Nanotechnology

Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures with at least one dimension sized from 1 to 100 nanometres.Quantum mechanical effects are important at this quantum-realm scale. Nanotechnology is considered a key technology for the future. Consequently, various governments have invested billions of dollars in its future. The USA has invested 3.7 billion dollars through its National Nanotechnology Initiative followed by Japan with 750 million and the European Union 1.2 billion.

Nanotechnology is very diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, from developing new materials with dimensions on the nanoscale to direct control of matter on the atomic scale. Nanotechnology entails the application of fields of science as diverse as surface science, organic chemistry, molecular biology, semiconductor physics,microfabrication, etc.

Scientists debate the future implications of nanotechnology. Nanotechnology may be able to create many new materials and devices with a vast range of applications, such as in medicine, electronics, biomaterials and energy production. On the other hand, nanotechnology raises many of the same issues as any new technology, including concerns about the toxicity and environmental impact of nanomaterials, and their potential effects on global economics, as well as speculation about various doomsday scenarios. These concerns have led to a debate among advocacy groups and governments on whether special regulation of nanotechnology is warranted.

Materials perspective

A number of physical phenomena become pronounced as the size of the system decreases. These include statistical mechanicaleffects, as well as quantum mechanical effects, for example the “quantum size effect” where the electronic properties of solids are altered with great reductions in particle size. This effect does not come into play by going from macro to micro dimensions. However, quantum effects become dominant when the nanometer size range is reached, typically at distances of 100 nanometers or less, the so calledquantum realm. Additionally, a number of physical (mechanical, electrical, optical, etc.) properties change when compared to macroscopic systems. One example is the increase in surface area to volume ratio altering mechanical, thermal and catalytic properties of materials. Diffusion and reactions at nanoscale, nanostructures materials and nanodevices with fast ion transport are generally referred to nanoionics. Mechanical properties of nanosystems are of interest in the nanomechanics research. The catalytic activity of nanomaterials also opens potential risks in their interaction with biomaterials.

Materials reduced to the nanoscale can show different properties compared to what they exhibit on a macroscale, enabling unique applications. For instance, opaque substances become transparent (copper); stable materials turn combustible (aluminum); insoluble materials become soluble (gold). A material such as gold, which is chemically inert at normal scales, can serve as a potent chemicalcatalyst at nanoscales. Much of the fascination with nanotechnology stems from these quantum and surface phenomena that matter exhibits at the nanoscale.


Molecular perspective

Modern synthetic chemistry has reached the point where it is possible to prepare small molecules to almost any structure. These methods are used today to manufacture a wide variety of useful chemicals such as pharmaceuticals or commercial polymers. This ability raises the question of extending this kind of control to the next-larger level, seeking methods to assemble these single molecules into supramolecular assemblies consisting of many molecules arranged in a well defined manner.

These approaches utilize the concepts of molecular self-assembly and/or supramolecular chemistry to automatically arrange themselves into some useful conformation through abottom-up approach. The concept of molecular recognition is especially important: molecules can be designed so that a specific configuration or arrangement is favored due to non-covalent intermolecular forces. The Watson–Crick basepairing rules are a direct result of this, as is the specificity of an enzyme being targeted to a single substrate, or the specificfolding of the protein itself. Thus, two or more components can be designed to be complementary and mutually attractive so that they make a more complex and useful whole.

Such bottom-up approaches should be capable of producing devices in parallel and be much cheaper than top-down methods, but could potentially be overwhelmed as the size and complexity of the desired assembly increases. Most useful structures require complex and thermodynamically unlikely arrangements of atoms. Nevertheless, there are many examples of self-assembly based on molecular recognition in biology, most notably Watson–Crick basepairing and enzyme-substrate interactions. The challenge for nanotechnology is whether these principles can be used to engineer new constructs in addition to natural ones.

Molecular nanotechnology

Molecular nanotechnology, sometimes called molecular manufacturing, describes engineered nanosystems (nanoscale machines) operating on the molecular scale. Molecular nanotechnology is especially associated with the molecular assembler, a machine that can produce a desired structure or device atom-by-atom using the principles ofmechanosynthesis. Manufacturing in the context of productive nanosystems is not related to, and should be clearly distinguished from, the conventional technologies used to manufacture nanomaterials such as carbon nanotubes and nanoparticles.

When the term "nanotechnology" was independently coined and popularized by Eric Drexler (who at the time was unaware of an earlier usage by Norio Taniguchi) it referred to a future manufacturing technology based on molecular machine systems. The premise was that molecular scale biological analogies of traditional machine components demonstrated molecular machines were possible: by the countless examples found in biology, it is known that sophisticated, stochastically optimised biological machines can be produced.

It is hoped that developments in nanotechnology will make possible their construction by some other means, perhaps using biomimetic principles. However, Drexler and other researchers have proposed that advanced nanotechnology, although perhaps initially implemented by biomimetic means, ultimately could be based on mechanical engineering principles, namely, a manufacturing technology based on the mechanical functionality of these components (such as gears, bearings, motors, and structural members) that would enable programmable, positional assembly to atomic specification. The physics and engineering performance of exemplar designs were analyzed in Drexler's bookNanosystems.

In general it is very difficult to assemble devices on the atomic scale, as all one has to position atoms on other atoms of comparable size and stickiness. Another view, put forth by Carlo Montemagno, is that future nanosystems will be hybrids of silicon technology and biological molecular machines. Yet another view, put forward by the late Richard Smalley, is that mechanosynthesis is impossible due to the difficulties in mechanically manipulating individual molecules.

This led to an exchange of letters in the ACS publication Chemical & Engineering News in 2003. Though biology clearly demonstrates that molecular machine systems are possible, non-biological molecular machines are today only in their infancy. Leaders in research on non-biological molecular machines are Dr. Alex Zettl and his colleagues at Lawrence Berkeley Laboratories and UC Berkeley. They have constructed at least three distinct molecular devices whose motion is controlled from the desktop with changing voltage: a nanotube nanomotor, a molecular actuator, and a nanoelectromechanical relaxation oscillator. See nanotube nanomotor for more examples.

An experiment indicating that positional molecular assembly is possible was performed by Ho and Lee at Cornell University in 1999. They used a scanning tunneling microscope to move an individual carbon monoxide molecule (CO) to an individual iron atom (Fe) sitting on a flat silver crystal, and chemically bound the CO to the Fe by applying a voltage.

Techniques

There are several important modern developments. The atomic force microscope and the Scanning Tunneling Microscope are two early versions of scanning probes that launched nanotechnology. There are other types ofscanning probe microscopy, all flowing from the ideas of the scanning confocal microscope developed by Marvin Minsky in 1961 and the scanning acoustic microscope developed by Calvin Quate and coworkers in the 1970s, that made it possible to see structures at the nanoscale.

The tip of a scanning probe can also be used to manipulate nanostructures (a process called positional assembly). Feature-oriented scanning methodology suggested by Rostislav Lapshin appears to be a promising way to implement these nanomanipulations in automatic mode. However, this is still a slow process because of low scanning velocity of the microscope.

Various techniques of nanolithography such as optical lithography, X-ray lithography dip pen nanolithography, electron beam lithography or nanoimprint lithography were also developed. Lithography is a top-down fabrication technique where a bulk material is reduced in size to nanoscale pattern.

Another group of nanotechnological techniques include those used for fabrication of nanotubes and nanowires, those used in semiconductor fabrication such as deep ultraviolet lithography, electron beam lithography, focused ion beam machining, nanoimprint lithography, atomic layer deposition, and molecular vapor deposition, and further including molecular self-assembly techniques such as those employing di-block copolymers. However, all of these techniques preceded the nanotech era, and are extensions in the development of scientific advancements rather than techniques which were devised with the sole purpose of creating nanotechnology and which were results of nanotechnology research.

The top-down approach anticipates nanodevices that must be built piece by piece in stages, much as manufactured items are made. Scanning probe microscopy is an important technique both for characterization and synthesis of nanomaterials. Atomic force microscopes and scanning tunneling microscopes can be used to look at surfaces and to move atoms around. By designing different tips for these microscopes, they can be used for carving out structures on surfaces and to help guide self-assembling structures. By using, for example, feature-oriented scanning approach, atoms or molecules can be moved around on a surface with scanning probe microscopy techniques. At present, it is expensive and time-consuming for mass production but very suitable for laboratory experimentation.

In contrast, bottom-up techniques build or grow larger structures atom by atom or molecule by molecule. These techniques include chemical synthesis, self-assembly and positional assembly. Dual polarisation interferometry is one tool suitable for characterisation of self assembled thin films. Another variation of the bottom-up approach is molecular beam epitaxy or MBE. Researchers at Bell Telephone Laboratories like John R. Arthur. Alfred Y. Cho, and Art C. Gossard developed and implemented MBE as a research tool in the late 1960s and 1970s. Samples made by MBE were key to the discovery of the fractional quantum Hall effect for which the 1998 Nobel Prize in Physics was awarded. MBE allows scientists to lay down atomically precise layers of atoms and, in the process, build up complex structures. Important for research on semiconductors, MBE is also widely used to make samples and devices for the newly emerging field of spintronics.

However, new therapeutic products, based on responsive nanomaterials, such as the ultradeformable, stress-sensitive Transfersome vesicles, are under development and already approved for human use in some countries.

Implications

The Center for Responsible Nanotechnology warns of the broad societal implications of untraceable weapons of mass destruction, networked cameras for use by the government, and weapons developments fast enough to destabilize arms races.

Another area of concern is the effect that industrial-scale manufacturing and use of nanomaterials would have on human health and the environment, as suggested bynanotoxicology research. For these reasons, groups such as the Center for Responsible Nanotechnology advocate that nanotechnology be regulated by governments. Others counter that overregulation would stifle scientific research and the development of beneficial innovations.

Some nanoparticle products may have unintended consequences. Researchers have discovered that bacteriostatic silver nanoparticles used in socks to reduce foot odor are being released in the wash. These particles are then flushed into the waste water stream and may destroy bacteria which are critical components of natural ecosystems, farms, and waste treatment processes.

Public deliberations on risk perception in the US and UK carried out by the Center for Nanotechnology in Society found that participants were more positive about nanotechnologies for energy applications than for health applications, with health applications raising moral and ethical dilemmas such as cost and availability.

Experts, including director of the Woodrow Wilson Center's Project on Emerging Nanotechnologies David Rejeski, have testified that successful commercialization depends on adequate oversight, risk research strategy, and public engagement. Berkeley, California is currently the only city in the United States to regulate nanotechnology; Cambridge, Massachusetts in 2008 considered enacting a similar law, but ultimately rejected it. Relevant for both research on and application of nanotechnologies, the insurability of nanotechnology is contested. Without state regulation of nanotechnology, the availability of private insurance for potential damages is seen as necessary to ensure that burdens are not socialised implicitly.

Health and environmental concerns

Researchers have found that when rats breathed in nanoparticles, the particles settled in the brain and lungs, which led to significant increases in biomarkers for inflammation and stress response and that nanoparticles induce skin aging through oxidative stress in hairless mice.

A two-year study at UCLA's School of Public Health found lab mice consuming nano-titanium dioxide showed DNA and chromosome damage to a degree "linked to all the big killers of man, namely cancer, heart disease, neurological disease and aging".

A major study published more recently in Nature Nanotechnology suggests some forms of carbon nanotubes – a poster child for the “nanotechnology revolution” – could be as harmful as asbestos if inhaled in sufficient quantities. Anthony Seaton of the Institute of Occupational Medicine in Edinburgh, Scotland, who contributed to the article on carbon nanotubes said "We know that some of them probably have the potential to cause mesothelioma. So those sorts of materials need to be handled very carefully." In the absence of specific regulation forthcoming from governments, Paull and Lyons (2008) have called for an exclusion of engineered nanoparticles in food. A newspaper article reports that workers in a paint factory developed serious lung disease and nanoparticles were found in their lungs.

Business

A business is an organization engaged in the trade of goods, services, or both to consumers.Businesses are predominant in capitalist economies, where most of them are privately owned and administered to earn profit to increase the wealth of their owners. Businesses may also be not-for-profit or state-owned. A business owned by multiple individuals may be referred to as a company, although that term also has a more precise meaning.

The etymology of "business" relates to the state of being busy either as an individual or society as a whole, doing commercially viable and profitable work. The term "business" has at least three usages, depending on the scope — the singular usage to mean a particular organization; the generalized usage to refer to a particular market sector, "the music business" and compound forms such asagribusiness; and the broadest meaning, which encompasses all activity by the community of suppliers of goods and services. However, the exact definition of business, like much else in the philosophy of business, is a matter of debate and complexity of meanings.

Forms of ownership

Although forms of business ownership vary by jurisdiction, there are several common forms which are as follows:

• Sole proprietorship: A sole proprietorship is a business owned by one person for-profit. The owner may operate the business alone or may employ others. The owner of the business has unlimited liability for the debts incurred by the business.
• Partnership: A partnership is a business owned by two or more people. In most forms of partnerships, each partner has unlimited liability for the debts incurred by the business. The three typical classifications of for-profit partnerships are general partnerships,limited partnerships, and limited liability partnerships.
• Corporation: A corporation is a limited liability business that has a separate legal personality from its members. Corporations can be either government-owned or privately owned, and corporations can organize either for-profit or not-for-profit. A privately owned, for-profit corporation is owned by shareholders who elect a board of directors to direct the corporation and hire its managerial staff. A privately owned, for-profit corporation can be either privately held or publicly held.
• Cooperative: Often referred to as a "co-op", a cooperative is a limited liability business that can organize for-profit or not-for-profit. A cooperative differs from a for-profit corporation in that it has members, as opposed to shareholders, who share decision-making authority. Cooperatives are typically classified as either consumer cooperatives orworker cooperatives. Cooperatives are fundamental to the ideology of economic democracy.

Management

The efficient and effective operation of a business, and study of this subject, is called management. The major branches of management are financial management, marketing management, human resource management, strategic management, production management, operations management, service management and information technology management.

Owners engage in business administration either directly or indirectly through the employment of managers. Owner managers, or hired managers administer to three component resources that constitute the business' value or worth: financial resources, capital or tangible resources, and human resources. These resources are administered to in at least five functional areas: legal contracting, manufacturing or service production, marketing, accounting, financing, and human resourcing.

Organization and government regulation

Most legal jurisdictions specify the forms of ownership that a business can take, creating a body of commercial law for each type.

The major factors affecting how a business is organized are usually:

• The size and scope of the business firm and its structure, management, and ownership, broadly analyzed in the theory of the firm. Generally a smaller business is more flexible, while larger businesses, or those with wider ownership or more formal structures, will usually tend to be organized as corporations or partnerships. In addition, a business that wishes to raise money on a stock market or to be owned by a wide range of people will often be required to adopt a specific legal form to do so.
• The sector and country. Private profit-making businesses are different from government-owned bodies. In some countries, certain businesses are legally obliged to be organized in certain ways.
• Limited Liability Companies , limited liability partnerships, and other specific types of business organization protect their owners or shareholders from business failure by doing business under a separate legal entity with certain legal protections. In contrast, unincorporated businesses or persons working on their own are usually not so protected.
• Tax advantages. Different structures are treated differently in tax law, and may have advantages for this reason.
• Disclosure and compliance requirements. Different business structures may be required to make less or more information public (or report it to relevant authorities), and may be bound to comply with different rules and regulations.

Many businesses are operated through a separate entity such as a corporation or a partnership. Most legal jurisdictions allow people to organize such an entity by filing certain charter documents with the relevant Secretary of State or equivalent and complying with certain other ongoing obligations. The relationships and legal rights of shareholders, limited partners, or members are governed partly by the charter documents and partly by the law of the jurisdiction where the entity is organized. Generally speaking, shareholders in a corporation, limited partners in a limited partnership, and members in a limited liability company are shielded from personal liabilityfor the debts and obligations of the entity, which is legally treated as a separate "person". This means that unless there is misconduct, the owner's own possessions are strongly protected in law if the business does not succeed.

Where two or more individuals own a business together but have failed to organize a more specialized form of vehicle, they will be treated as a general partnership. The terms of a partnership are partly governed by a partnership agreement if one is created, and partly by the law of the jurisdiction where the partnership is located. No paperwork or filing is necessary to create a partnership, and without an agreement, the relationships and legal rights of the partners will be entirely governed by the law of the jurisdiction where the partnership is located.

A single person who owns and runs a business is commonly known as a sole proprietor, whether that person owns it directly or through a formally organized entity.

A few relevant factors to consider in deciding how to operate a business include:

1. General partners in a partnership (other than a limited liability partnership), plus anyone who personally owns and operates a business without creating a separate legal entity, are personally liable for the debts and obligations of the business.
2. Generally, corporations are required to pay tax just like "real" people. In some tax systems, this can give rise to so-called double taxation, because first the corporation pays tax on the profit, and then when the corporation distributes its profits to its owners, individuals have to include dividends in their income when they complete their personal tax returns, at which point a second layer of income tax is imposed.
3. In most countries, there are laws which treat small corporations differently than large ones. They may be exempt from certain legal filing requirements or labor laws, have simplified procedures in specialized areas, and have simplified, advantageous, or slightly different tax treatment.
4. To "go public" -- which basically means to allow a part of the business to be owned by a wider range of investors or the public in general—you must organize a separate entity, which is usually required to comply with a tighter set of laws and procedures. Most public entities are corporations that have sold shares, but increasingly there are also public LLCs that sell units (sometimes also called shares), and other more exotic entities as well. However, you cannot take a general partnership "public."

Commercial law

Most commercial transactions are governed by a very detailed and well-established body of rules that have evolved over a very long period of time, it being the case that governing trade and commerce was a strong driving force in the creation of law and courts in Western civilization.

As for other laws that regulate or impact businesses, in many countries it is all but impossible to chronicle them all in a single reference source. There are laws governing treatment of labor and generally relations with employees, safety and protection issues , anti-discrimination laws (age, gender, disabilities, race, and in some jurisdictions, sexual orientation), minimum wage laws, unionlaws, workers compensation laws, and annual vacation or working hours time.

In some specialized businesses, there may also be licenses required, either due to special laws that govern entry into certain trades, occupations or professions, which may require special education, or by local governments. Professions that require special licenses range from law and medicine to flying airplanes to selling liquor to radio broadcasting to selling investment securities to selling used cars to roofing. Local jurisdictions may also require special licenses and taxes just to operate a business without regard to the type of business involved.

Some businesses are subject to ongoing special regulation. These industries include, for example, public utilities, investment securities, banking, insurance, broadcasting, aviation, and health care providers. Environmental regulations are also very complex and can impact many kinds of businesses in unexpected ways.

Capital

When businesses need to raise money, more laws come into play. A highly complex set of laws and regulations govern the offer and sale of investment securities (the means of raising money) in most Western countries. These regulations can require disclosure of a lot of specific financial and other information about the business and give buyers certain remedies. Because "securities" is a very broad term, most investment transactions will be potentially subject to these laws, unless a special exemption is available.

Capital may be raised through private means, by public offer  on a stock exchange, or in many other ways. Major stock exchanges include the Shanghai Stock Exchange, Singapore Exchange, Hong Kong Stock Exchange, New York Stock Exchange and Nasdaq, the London Stock Exchange , the Tokyo Stock Exchange , Bombay Stock Exchange and so on. Most countries with capital markets have at least one.

Businesses that have gone "public" are subject to extremely detailed and complicated regulation about their internal governance (such as how executive officers' compensation is determined) and when and how information is disclosed to the public and their shareholders. In the United States, these regulations are primarily implemented and enforced by the United States Securities and Exchange Commission . Other Western nations have comparable regulatory bodies. The regulations are implemented and enforced by the China Securities Regulation Commission, in China. In Singapore, the regulation authority is Monetary Authority of Singapore , and in Hong Kong, it is Securities and Futures Commission .

As noted at the beginning, it is impossible to enumerate all of the types of laws and regulations that impact on business today. In fact, these laws have become so numerous and complex, that no business lawyer can learn them all, forcing increasing specialization among corporate attorneys. It is not unheard of for teams of 5 to 10 attorneys to be required to handle certain kinds of corporate transactions, due to the sprawling nature of modern regulation. Commercial law spans general corporate law, employment and labor law, health-care law, securities law, M&A law , tax law, ERISA law , food and drug regulatory law, intellectual property law , telecommunications law, and more.

Intellectual property

Businesses often have important "intellectual property" that needs protection from competitors for the company to stay profitable. This could require patents, copyrights, trademarks or preservation of trade secrets. Most businesses have names, logos and similar branding techniques that could benefit from trademarking. Patents and copyrights in the United States are largely governed by federal law, while trade secrets and trademarking are mostly a matter of state law. Because of the nature of intellectual property, a business needs protection in every jurisdiction in which they are concerned about competitors. Many countries are signatories to international treaties concerning intellectual property, and thus companies registered in these countries are subject to national laws bound by these treaties. In order to protect trade secrets, companies may require employees to sign non-compete clauses which will impose limitations on an employees interactions with stakeholders, and competitors.

Impact of nanotechnology

The impact of nanotechnology extends from its medical, ethical, mental, legal and environmental applications, to fields such as engineering, biology, chemistry, computing, materials science, military applications, and communications.

Major benefits of nanotechnology include improved manufacturing methods, water purification systems, energy systems, physical enhancement, nanomedicine, better food production methods and nutrition and large scale infrastructure auto-fabrication.Nanotechnology's reduced size may allow for automation of tasks which were previously inaccessible due to physical restrictions, which in turn may reduce labor, land, or maintenance requirements placed on humans.

Potential risks include environmental, health, and safety issues; transitional effects such as displacement of traditional industries as the products of nanotechnology become dominant; military applications such as biological warfare and implants for soldiers; and surveillance through nano-sensors, which are of concern to privacy rights advocates. These may be particularly important if potential negative effects of nanoparticles are overlooked before they are released.

Whether nanotechnology merits special government regulation is a controversial issue. Regulatory bodies such as the United States Environmental Protection Agency and the Health & Consumer Protection Directorate of the European Commission have started dealing with the potential risks of nanoparticles. The organic food sector has been the first to act with the regulated exclusion of engineered nanoparticles from certified organic produce, firstly in Australia and the UK, and more recently in Canada, as well as for all food certified to Demeter Internationalstandards

Health and safety impact from nanoparticles

The presence of nanomaterials (materials that contain nanoparticles) is not in itself a threat. It is only certain aspects that can make them risky, in particular their mobility and their increased reactivity. Only if certain properties of certain nanoparticles were harmful to living beings or the environment would we be faced with a genuine hazard. In this case it can be called nanopollution.

In addressing the health and environmental impact of nanomaterials we need to differentiate between two types of nanostructures: (1) Nanocomposites, nanostructured surfaces and nanocomponents (electronic, optical, sensors etc.), where nanoscale particles are incorporated into a substance, material or device (“fixed” nano-particles); and (2) “free” nanoparticles, where at some stage in production or use individual nanoparticles of a substance are present. These free nanoparticles could be nanoscale species of elements, or simple compounds, but also complex compounds where for instance a nanoparticle of a particular element is coated with another substance (“coated” nanoparticle or “core-shell” nanoparticle).

There seems to be consensus that, although one should be aware of materials containing fixed nanoparticles, the immediate concern is with free nanoparticles.

Nanoparticles are very different from their everyday counterparts, so their adverse effects cannot be derived from the known toxicity of the macro-sized material. This poses significant issues for addressing the health and environmental impact of free nanoparticles.

To complicate things further, in talking about nanoparticles it is important that a powder or liquid containing nanoparticles almost never be monodisperse , but contain instead a range of particle sizes. This complicates the experimental analysis as larger nanoparticles might have different properties from smaller ones. Also, nanoparticles show a tendency to aggregate, and such aggregates often behave differently from individual nanoparticles.

The lethal dose over six months for lab rats, of different kinds of nanoparticles are often characterized by a Skov Kjaer index, named after the scientist Kasper Skov Kjaer.

The National Institute for Occupational Safety and Health has conducted initial research on how nanoparticles interact with the body’s systems and how workers might be exposed to nano-sized particles in the manufacturing or industrial use of nanomaterials. NIOSH currently offers interim guidelines for working with nanomaterials consistent with the best scientific knowledge.

In "The Consumer Product Safety Commission and Nanotechnology," E. Marla Felcher suggests that the Consumer Product Safety Commission, which is charged with protecting the public against unreasonable risks of injury or death associated with consumer products, is ill-equipped to oversee the safety of complex, high-tech products made using nanotechnology.

Longer-term concerns center on the impact that new technologies will have for society at large, and whether these could possibly lead to either a post-scarcity economy, or alternatively exacerbate the wealth gap between developed and developing nations. The effects of nanotechnology on the society as a whole, on human health and the environment, on trade, on security, on food systems and even on the definition of "human", have not been characterized or politicized.

The health impact of nanotechnology are the possible effects that the use of nanotechnological materials and devices will have on human health. As nanotechnology is an emerging field, there is great debate regarding to what extent nanotechnology will benefit or pose risks for human health. Nanotechnology's health impact can be split into two aspects: the potential for nanotechnological innovations to have medical applications to cure disease, and the potential health hazards posed by exposure to nanomaterials.

Nanotoxicology is the field which studies potential health risks of nanomaterials. The extremely small size of nanomaterials means that they are much more readily taken up by the human body than larger sized particles. How these nanoparticles behave inside the organism is one of the significant issues that needs to be resolved. The behavior of nanoparticles is a function of their size, shape and surface reactivity with the surrounding tissue. Apart from what happens if non-degradable or slowly degradable nanoparticles accumulate in organs, another concern is their potential interaction with biological processes inside the body: because of their large surface, nanoparticles on exposure to tissue and fluids will immediately adsorb onto their surface some of the macromolecules they encounter. The large number of variables influencing toxicity means that it is difficult to generalise about health risks associated with exposure to nanomaterials – each new nanomaterial must be assessed individually and all material properties must be taken into account. Health and environmental issues combine in the workplace of companies engaged in producing or using nanomaterials and in the laboratories engaged in nanoscience and nanotechnology research. It is safe to say that current workplace exposure standards for dusts cannot be applied directly to nanoparticle dusts.

Nanomedicine is the medical application of nanotechnology. The approaches to nanomedicine range from the medical use of nanomaterials, to nanoelectronic biosensors, and even possible future applications of molecular nanotechnology. Nanomedicine seeks to deliver a valuable set of research tools and clinically helpful devices in the near future.The National Nanotechnology Initiative expects new commercial applications in the pharmaceutical industry that may include advanced drug delivery systems, new therapies, and in vivo imaging. Neuro-electronic interfaces and other nanoelectronics-based sensors are another active goal of research. Further down the line, the speculative field of molecular nanotechnology believes that cell repair machines could revolutionize medicine and the medical field.

Environmental issues

Nanopollution is a generic name for all waste generated by nanodevices or during the nanomaterials manufacturing process. This kind of waste may be very dangerous because of its size. It can float in the air and might easily penetrate animal and plant cells causing unknown effects. Most human-made nanoparticles do not appear in nature, so living organisms may not have appropriate means to deal with nanowaste.

To properly assess the health hazards of engineered nanoparticles the whole life cycle of these particles needs to be evaluated, including their fabrication, storage and distribution, application and potential abuse, and disposal. The impact on humans or the environment may vary at different stages of the life cycle. Environmental assessment is justified as nanoparticles present novel (new) environmental impacts. Scrinis raises concernsabout nano-pollution, and argues that it is not currently possible to “precisely predict or control the ecological impacts of the release of these nano-products into the environment.”

On the other hand, some possible future applications of nanotechnology have the potential to benefit the environment. Nanofiltration, based on the use of membranes with extremely small pores smaller than 10 nm  are suitable for a mechanical filtration for the removal of ions or the separation of different fluids. Furthermore, magnetic nanoparticles offer an effective and reliable method to remove heavy metal contaminants from waste water. Using nanoscale particles increases the efficiency to absorb the contaminants and is comparatively inexpensive compared to traditional precipitation and filtration methods.

Furthermore, nanotechnology could potentially have a great impact on clean energy production. Research is underway to use nanomaterials for purposes including more efficient solar cells, practical fuel cells, and environmentally friendly batteries.

Societal impact

Beyond the toxicity risks to human health and the environment which are associated with first-generation nanomaterials, nanotechnology has broader societal impact and poses broader social challenges. Social scientists have suggested that nanotechnology's social issues should be understood and assessed not simply as "downstream" risks or impacts. Rather, the challenges should be factored into "upstream" research and decision making in order to ensure technology development that meets social objectives

Many social scientists and organizations in civil society suggest that technology assessment and governance should also involve public participation

Societal risks from the use of nanotechnology have also been raised. On the instrumental level, these include the possibility of military applications of nanotechnology (for instance, as in implants and other means for soldier enhancement like those being developed at the Institute for Soldier Nanotechnologies at MIT ) as well as enhanced surveillance capabilities through nano-sensors.

The last few years has seen a gold rush to claim patents at the nanoscale. Over 800 nano-related patents were granted in 2003, and the numbers are increasing year to year. Corporations are already taking out broad-ranging patents on nanoscale discoveries and inventions. For example, two corporations, NEC and IBM, hold the basic patents on carbon nanotubes, one of the current cornerstones of nanotechnology. Carbon nanotubes have a wide range of uses, and look set to become crucial to several industries from electronics and computers, to strengthened materials to drug delivery and diagnostics. Carbon nanotubes are poised to become a major traded commodity with the potential to replace major conventional raw materials. However, as their use expands, anyone seeking to (legally) manufacture or sell carbon nanotubes, no matter what the application, must first buy a license from NEC or IBM.

Potential benefits and risks for developing countries

Nanotechnologies may provide new solutions for the millions of people in developing countries who lack access to basic services, such as safe water, reliable energy, health care, and education. The United Nations has set Millennium Development Goals for meeting these needs. The 2004 UN Task Force on Science, Technology and Innovation noted that some of the advantages of nanotechnology include production using little labor, land, or maintenance, high productivity, low cost, and modest requirements for materials and energy.

Potential opportunities of nanotechnologies to help address critical international development priorities include improved water purification systems, energy systems, medicine and pharmaceuticals, food production and nutrition, and information and communications technologies. Nanotechnologies are already incorporated in products that are on the market. Other nanotechnologies are still in the research phase, while others are concepts that are years or decades away from development.

Protection of the environment, human health and worker safety in developing countries often suffers from a combination of factors that can include but are not limited to lack of robust environmental, human health, and worker safety regulations; poorly or unenforced regulation which is linked to a lack of physical (e.g., equipment) and human capacity (i.e., properly trained regulatory staff). Often, these nations require assistance, particularly financial assistance, to develop the scientific and institutional capacity to adequately assess and manage risks, including the necessary infrastructure such as laboratories and technology for detection.

However, concerns are frequently raised that the claimed benefits of nanotechnology will not be evenly distributed, and that any benefits (including technical and/or economic) associated with nanotechnology will only reach affluent nations. The majority of nanotechnology research and development - and patents for nanomaterials and products - is concentrated in developed countries (including the United States, Japan, Germany, Canada and France). In addition, most patents related to nanotechnology are concentrated amongst few multinational corporations, including IBM, Micron Technologies, Advanced Micro Devices and Intel. This has led to fears that it will be unlikely that developing countries will have access to the infrastructure, funding and human resources required to support nanotechnology research and development, and that this is likely to exacerbate such inequalities.

Producers in developing countries could also be disadvantaged by the replacement of natural products (including rubber, cotton, coffee and tea) by developments in nanotechnology. These natural products are important export crops for developing countries, and many farmers' livelihoods depend on them. It has been argued that their substitution with industrial nano-products could negatively affect the economies of developing countries, that have traditionally relied on these export crops.

Effects on laborers

Ray Kurzweil has speculated in The Singularity is Near that people who work in unskilled labor jobs for a livelihood may become the first human workers to be displaced by the constant use of nanotechnology in the workplace, noting that layoffs often affect the jobs based around the lowest technology level before attacking jobs with the highest technology level possible. It has been noted that every major economic era has stimulated a global revolution both in the kinds of jobs that are available to people and the kind of training they need to achieve these jobs, and there is concern that the world's educational systems have lagged behind in preparing students for the "Nanotech Age".

It has also been speculated that nanotechnology may give rise to nanofactories which may have superior capabilities to conventional factories due to their small carbon and physical footprint on the global and regional environment. The miniaturization and transformation of the multi-acre conventional factory into the nanofactory may not interfere with their ability to deliver a high quality product; the product may be of even greater quality due to the lack of human errors in the production stages. Nanofactory systems may use precise atomic precisioning and contribute to making superior quality products that the "bulk chemistry" method used in 20th century and early 21st currently cannot produce. These advances might shift the computerized workforce in an even more complex direction, requiring skills in genetics, nanotechnology, and robotics.

Impact of molecular nanotechnology

Molecular nanotechnology is a speculative subfield of nanotechnology regarding the possibility of engineering molecular assemblers, machines which could re-order matter at a molecular or atomic scale. Regarding the risks from molecular manufacturing, an often cited worst-case scenario is "grey goo", a hypothetical substance into which the surface of the earth might be transformed by self-replicating nanobots running amok. This concept has been analyzed by Freitas in "Some Limits to Global Ecophagy by Biovorous Nanoreplicators, with Public Policy Recommendations" With the advent of nan-biotech, a different scenario called green goo has been forwarded. Here, the malignant substance is not nanobots but rather self-replicating organisms engineered through nanotechnology.

According to the Center for Responsible Nanotechnology:
          Molecular manufacturing allows the cheap creation of incredibly powerful devices and products. How many of these products will we want? What environmental damage will they do? The range of possible damage is vast, from personal low-flying supersonic aircraft injuring large numbers of animals to collection of solar energy on a sufficiently large scale to modify the planet's albedo and directly affect the environment. Stronger materials will allow the creation of much larger machines, capable of excavating or otherwise destroying large areas of the planet at a greatly accelerated pace.

It is too early to tell whether there will be economic incentive to do this. However, given the large number of activities and purposes that would damage the environment if taken to extremes, and the ease of taking them to extremes with molecular manufacturing, it seems likely that this problem is worth worrying about. Some forms of damage can result from an aggregate of individual actions, each almost harmless by itself. Such damage is quite hard to prevent by persuasion, and laws frequently don't work either; centralized restriction on the technology itself may be a necessary part of the solution.

Finally, the extreme compactness of nanomanufactured machinery will tempt the use of very small products, which can easily turn into nano-litter that will be hard to clean up and may cause health problems. The site list numerous other risks and benefits.

The Business Of Nanotech

Pity the poor alchemists. They spent the Middle Ages in candle-lit laboratories, laboring to brew universal elixirs and to turn base metals into gold or silver. They failed utterly. By the dawn of the Scientific Revolution, researchers equipped with microscopes founded modern chemistry -- and dismissed alchemy as hocus-pocus.

But it turns out alchemists were just a few centuries ahead of schedule. Today, in sparkling labs equipped with powerful microscopes, scientists on three continents are promising dramatic new materials and medicines that would make alchemists proud. This work takes place in the realm of nanotechnology, industry's tiniest stage. The standard unit of measurement, a nanometer, is a billionth of a meter -- barely the size of 10 hydrogen atoms in a row. In this universe entire dramas can unfold on the tip of a pin, and a sneeze packs the punch of a raging hurricane.

Why so small? Researchers have discovered that matter at this tiny scale often behaves very differently. While some of the science behind this phenomenon is still shrouded in mystery, the commercial potential of the infinitesimal is coming sharply into focus. Familiar materials -- from gold to carbon soot -- display startling and useful new properties. Some transmit light or electricity. Others become harder than diamonds or turn into potent chemical catalysts. What's more, researchers find that a tiny dose of nanoparticles can transform the chemistry and nature of far bigger things, creating everything from fortified fenders to superefficient fuel cells. Engineers working at the nano scale have a brand-new tool kit that's full of wonder and brimming with potential riches.

Now it's time to start cashing in. Throughout 2005, companies large and small will be rushing more nano-based products from labs to the marketplace. Consumers will encounter nanotechnology in the form of nick-proof trims on Hummers, Wilson tennis racquets with extra pop, even golf balls designed to fly straight. Investors, meanwhile, will be faced with a slew of bold announcements. On Feb. 1, for example, computer giant Hewlett-Packard Co. disclosed a breakthrough in nanotechnology that, within a decade, could carry computing beyond today's silicon and transistors. "We are reinventing the computer at the molecular scale," says Stan Williams, an HP senior fellow and co-author of the report.

For now, nano is starting out modestly. The biggest markets for nanoparticles remain in familiar products, from the black rubber filler in tires, a $4 billion industry, to the silver used in traditional photography. Lux Research Inc., a New York nanotech market researcher, estimates that only $13 billion worth of manufactured goods will incorporate nanotechnologies this year. That's little more than a rounding error in the global economy.

Feverish Activity
Yet new nano-based products that could have a far bigger impact are only a step or two away. Within the next two years, diagnostic machines with components built at the nano scale should allow doctors and nurses to carry pint-size laboratories in their briefcases, perhaps to test for HIV or count white blood cells on the spot. Nano sensors will scour airports and post offices for anthrax and sarin. Toward the end of the decade, scientists say, new computer memories composed of nanoparticles could conceivably pack the digital contents of the Library of Congress into a machine the size of a yo-yo. By that point, Lux predicts, nanotechnologies will have worked their way into a universe of products worth $292 billion.

How does nanotechnology conjure up such surprises? Nature provides examples of this molecular magic. Think of coal compressing, over millennia, into diamonds. The gems are made of the same carbon atoms. But they've been rejiggered over time into orderly crystal patterns linked by superstrong chemical bonds. Soft becomes hard, sooty blackness becomes glittering clarity.

These days scientists can pull off such transformations between coffee breaks. With atomic probes they manipulate molecules, one-upping Mother Nature. Delving into the nano realm gives them startling surprises right in the old periodic table of elements -- and they're filing a flurry of patents to lay claim to these miraculous materials. "It's a land grab," says Douglas Sharrott, a patent lawyer at Fitzpatrick, Cella, Harper & Scinto in New York.

The questions around nano are no longer whether it's coming or if it's real but just how big it will be. Some see nano simply as a new material revolution, akin to the dawn of plastics. Others herald a transition as dramatic as mankind's advance from stone to metal tools. But those hazy predictions aside, the questions that are echoing from laboratories in Tokyo to the hectic offices of short-sellers on Wall Street are about money. Which nanotechnologies will create new fortunes, industries, and corporate champs?

Activity on the ground is feverish. Some 1,200 nano startups have emerged around the world, half of them in the U.S. Companies that long labored in dull-as-dishwater materials businesses are finding that they can create a stir by trumpeting their mastery over age-old particles, from specks of ceramic to soot. Brokerages such as Merrill Lynch & Co. and Punk, Ziegle & Co. are scouring the markets for nano-focused companies and plunking them into nano indexes. Meanwhile, investors, torn between an alluring new market and the fear of a dot-com-like bubble, are struggling to get a grip on exactly what nano means for them.

Their confusion is understandable. Nano is not a single industry but a scale of engineering involving matter between 1 and 100 nanometers. Instead of one new phenomenon, like the Internet, nano offers new possibilities for thousands of materials that already exist. This means much of the early activity will likely take place at industrial giants. Already, 19 of the 30 companies in the Dow Jones industrial index have launched nano initiatives. Says Margaret Blohm, manager of General Electric's nanotechnology research and development program: "I lose sleep at night because expectations are so high."

How do these tiny molecules create big new products? Sometimes size alone is the key. Consider DuPont's new Voltron, a super-durable wire coating used in heavy-duty electric motors. If you looked at previous generations of such coatings through a powerful microscope, the chemical components would look loosely packed, with irregular spaces between the molecules. This structure leads the material to break down more easily. Voltron's nanoscale particles fill in many of the voids, making a stronger insulator that lasts longer. In DuPont's tests on electric motors, a coating of Voltron extended the time between failures by a factor of 10, to more than 1,000 hours. And since such motors consume an estimated 65% of U.S. electric power, lengthening their life and efficiency promises big energy savings. "This chemical combination can only be done with nanomaterials," says Krish Doraiswany, a senior planning manager for DuPont's nanotech research effort.

Most of the early advances in nano will improve what we already have. Examples: lightweight army fatigues that resist chemical weapons and food packaging designed to keep last month's lettuce green and crunchy. Later this year, duffers will be able to buy golf balls manufactured by NanoDynamics Inc. in Buffalo, N.Y., that are designed to prevent a shift in weight as they spin. This should create balls that fly straight down the fairway and even hold a steadier line on the putting green. "If demand for the balls takes off, this could become a major business for us," says NanoDynamics CEO Keith Blakely, who plans to sell the balls for a pricey $5 apiece.

Beyond straight putts and fresh produce, can nano live up to its potential to create entirely new industries and corporate titans? The answer depends on how the players, from regulators to entrepreneurs, handle a host of thorny challenges. Governments must devise smart regulations to control new materials and therapies. Companies face logistical conundrums, such as carrying out quality control on shipments of minuscule carbon nanotubes and silicon crystals -- the I-beams and sheet glass of this industrial revolution -- that are virtually invisible.

The nascent industry also must hammer out standards and enforcement practices that are sorely lacking. A 2004 study by Lux Research found that many of the 200 global suppliers of basic nanomaterials failed to deliver what they promised. "As a group they have a frighteningly poor track record," says Lux Vice-President Matthew Nordon. The upshot? Until the industry puts a qualified supply chain in place, only innovators working with world-class labs can count on reliable material. This limits access to nanotechnology and hurts its growth.

An even greater challenge for nano industries is to ensure that their new materials are safe in the human body and in the environment. Setbacks could sink nano companies and even lead to a global backlash among the same activists who are raging against genetically modified food. "I'm worried about an overreaction to both the hype and the fear," says Kristen Kulinowski, an executive director at Rice University's Center for Biological & Environmental Nanotechnology.

Such concerns rattle the equity markets. As recently as last summer, about a dozen nanotech companies were positioning themselves for initial public offerings. But last year's most widely anticipated IPO in the sector -- a $115 million offering for Nanosys Inc. in August -- was withdrawn at the last minute as investors cooled to a company rich in patents but still years from making a profit. Now the IPO market appears stalled, even for stars such as Nanofilm, a profitable Valley View  manufacturer of optical films, and Konarka Technologies Inc., a Lowell leader in plastic solar panels.

Premature Marketing?
Doubts and confusion plague the market, where even the definition of nano is open to debate. When Merrill Lynch analysts released their Nano Index last April featuring 25 companies, critics howled that they were fueling hype -- and that a few of the pharmaceutical outfits on the list were included simply because they engaged in the common practice of making molecules. Merrill retooled the list, limiting it to companies that publicly stress a commitment to nano. Still, Manuel P. Asensio, president of Asensio & Co., a short-seller that is still betting against the stock of one nano index company -- NVE Corp. a maker of electronic sensor instruments -- continues to grumble. "There is no market yet," he says. "Isn't Merrill attempting to create a retail fervor?" Merrill's Steven Milunovich, who directs its nanotech research, responds that the firm covers only three of the stocks on the index and compiles the list not to recommend investment vehicles but as a way to track the young industry. "It's a 30-year trend, and we're only at the beginning," he says.

In today's cautious climate, investors are focusing less on dazzling visions and more on companies with real products, customers, and profits. The leading performer in Merrill's index in 2004 was MTS Systems Corp. a 39-year-old testing-equipment company whose tools are widely used in nano labs. Its stock rose 80%. Harris & Harris Group Inc. a venture-capital firm with heavy investments in nano, saw its stock rise 75% -- a sign that investors hold high hopes for the segment. But most businesses selling true nano products, from materials company Altair Nanotechnologies Inc. to France's Flamel Technologies , a medical supplier, suffered market declines through 2004. And the Merrill index fell another 12% in January, 2005.

No doubt nano is in for its share of bumps, with flops sure to outnumber successes by a wide margin. Yet the technology of the tiny is on track to disrupt nearly everything in its path, including companies, industries, and universities. Why? At the atomic level the boundaries among biology, chemistry, physics, and electronics lose much of their meaning. The sciences start to merge. Many of the winners in nano will be those that can reach across old boundaries and create novel hybrids. Israeli biologists and electrical engineers, for example, have teamed up to attach dna to carbon nanotubes to create microscopic transistors. These assemble themselves in the lab following a biological blueprint. The result is an inanimate transistor -- but one that grows, like a tadpole or a toenail.

Funding Magnet
Companies that can bring such innovations to market stand to restructure entire industries. Korea's Samsung Group plans to produce TV displays featuring the most prominent building blocks of the Nano Age -- carbon nanotubes -- by 2006. If successful, these screens could be lighter, cheaper, brighter, and more energy-efficient than today's models. The technology would spread quickly from TVs to computer screens, even electronic billboards. GE is adding a new nano-focused wing to its R&D center in Niskayuna, N.Y. The company won't disclose the size of its investment but says a 50-member team of researchers is looking to seed nano into everything from medical technology to lighting to high-performance turbines.

For entrepreneurs, nano spells funding. Venture capitalists have invested $1 billion in nano companies, nearly half of it in the past two years. Meanwhile, government funding is holding steady at $4.7 billion annually, nearly equally divided among Asia, Europe, and North America. The cash is pouring into university labs and new nano corridors from Albany to Shanghai and Fukuoka prefecture in Japan. "Any professor with his head screwed on has moved research programs into nano," says Greg Blonder, a partner at Morgenthaler Ventures.

Many of the early prospectors are focusing on health-care testing tools, which are far less regulated than medicines and therapies. LabNow Inc., an Austin (Tex.) startup, has its sights set on addressing the AIDS epidemic. Using minute channels and sensors, the company has devised a blood laboratory on a chip the size of a business card. The patient places a single drop of blood on the chip, which is then inserted into a small electronic reader. Within minutes, HIV/AIDS patients can get a count of their white blood cells -- a crucial metric for treatment. Currently that test takes weeks or months in poor regions of the world, where blood samples are trundled back and forth in slow trucks. Patients can die waiting for the results. LabNow's technology has the potential to speed AIDS treatment in much of the world -- and let LabNow cash in on the $5 billion global market for point-of-care testing. In October, LabNow got $14 million in equity funding from a consortium led by George Soros. The company hopes to roll out its systems in South Africa by the end of 2005.

Red Flag
More dramatic breakthroughs are expected within two or three years as companies developing novel medical procedures begin to emerge from the regulatory maze. Already, nano-ized versions of existing drugs are causing a stir. Last month, American Pharmaceutical Partners Inc. shares surged 50% on news that the Food and Drug Administration had approved the marketing of Abraxane, a nanoscale protein-based drug for the treatment of metastatic breast cancer. The nano version is able to squeeze into places in the body that its existing macro counterpart cannot without intolerable side effects. Further out, researchers are working on customized treatments, such as nanoparticles built to match the unique genetic profile of a patient's cancer cells -- and programmed to seek out and destroy them. Hundreds of these therapies are in the works. Most will fail. But if even a handful succeed, they could change medicine.

To achieve such triumphs, nano companies must squelch fears about the effects of the particles in the body. Worries grew last spring when researchers at Southern Methodist University reported brain damage in a large-mouth bass that had been swimming in an aquarium stoked with common carbon-based nanoparticles known as buckyballs. Although far from conclusive, such findings raise red flags worldwide -- and they extend far beyond the networked legions of activists. Last year, giant reinsurer Swiss Reinsurance Co. warned against a rush into nano, citing "the unforeseeable nature of the risks it entails and the recurrent and cumulative losses it could lead to."

One industry that should be able to tap nano's potential without those risks is semiconductors. As the circuits and pathways on the chips grow tinier, manufacturers are running into problems. Electrons tunnel through flimsy walls that are only several atoms thick. The electricity coursing through the intricate maze generates searing heat, which is increasingly costly and hard to control. As the industry struggles to maintain Moore's Law, which predicts the doubling of computing power every 18 months, costs are exploding. The price of a new semiconductor fabricating plant is projected to reach $10 billion by the end of the decade.

Nano innovators aren't likely to replace the silicon chip anytime soon, but they could help ease the squeeze over the next decade. This process has already started with memory chips, the least complicated kind. Within two or three years, developers hope to make viable memory chips from spaghetti-shaped carbon nanotubes, each one only 1 nm wide. Further out, engineers are learning how to replace minuscule metal circuits and gateways on today's chips with new nano-engineered materials. IBM researchers have built transistors with carbon nanotubes that promise "a huge leap in performance while cutting heat loss," says Phaedon Avouris, a researcher at Big Blue's Nanometer Scale Science & Technology Labs.

Despite this progress, it's a long hike to nanocomputing, not a sprint. HP researchers don't expect their platinum circuits to debut until 2011 at the earliest. And it won't be until much later in the next decade, say scientists, that nanotechnology may be able to provide a new architecture for faster computing in the post-Silicon era.

The future of nanotechnology? It may seem strange now, but within a decade or so the term is likely to vanish from syllabuses and portfolios and remain part of company names only as a vestige of the past. After all, nano denotes only size. Once work on that scale becomes routine, that buzzword will fade. But the physical world -- medicines, metals, and even the roles the elements play -- will be utterly changed by this revolution, all brought about by bits far too small for the eye to see.

What are the Possible Dangers of Nanotechnology

Nanotechnology is a branch of science that deals with particles 1-100 nanometers in size. Experts believe possible dangers of nanotechnology lie in how these tiny particles might interact with the environment, and more importantly, with the human body. Billions of dollars are being spent to incorporate nanoparticles into products that are already being marketed to the public; when this investment is compared to the the comparatively scant research into nanotech health issues, some scientists become concerned.

Experts say the issue is that elements encountered at the nanoscale behave differently than their larger counterparts. As an example, graphite's properties are well known and it holds specific position in toxicology guidelines. Nobel winning physicist Richard Smalley of Rice University discovered carbon nanotubes and fullerenes — nanoparticles of carbon — which are legally categorized as graphite, yet they behave in ways unlike graphite making the classification a potentially dangerous one.

Case in point: in March 2004 tests conducted by environmental toxicologist Eva Oberdörster, Ph.D., with Southern Methodist University in Texas found extensive brain damage to fish exposed to fullerenes for a period of just 48 hours at a relatively moderate dose of 0.5 parts per million (commiserate with levels of other kinds of pollution found in bays). The fish also exhibited changed gene markers in their livers, indicating their entire physiology was affected. In a concurrent test, the fullerenes killed water fleas, an important link in the marine food chain.

Oberdörster could not say whether fullerenes would also cause brain damage in humans but cautioned that more studies are necessary and that the accumulation of fullerenes over time could be a concern, particularly if they were allowed to enter the food chain. Earlier studies in 2002 by CBEN (Center for Biological and Environmental Nanotechnology) indicated nanoparticles accumulated in the bodies of lab animals, and still other studies showed fullerenes travel freely through soil and could be absorbed by earthworms. This is a potential link up the food chain to humans and presents one of the possible dangers of nanotechnology.

Other nanoparticles have also been shown to have adverse effects. Research from University of California in San Diego in early 2002 revealed cadmium selenide nanoparticles, also called quantum dots, can cause cadmium poisoning in humans. In 2004 British scientist Vyvyan Howard published initial findings that indicated gold nanoparticles might move through a mother's placenta to the fetus; and as far back as 1997 scientists at Oxford discovered nanoparticles used in sunscreen created free radicals that damaged.

Complicating the dangers of nanotechnology, size and shape of nanoparticles affect the level of toxicity, preempting the ease of uniform categories even when considering a single element. In general, experts report smaller particles are more bioactive and toxic. Their ability to interact with other living systems increases because they can easily cross the skin, lung, and in some cases the blood/brain barriers. Once inside the body, there may be further biochemical reactions like the creation of free radicals that damage cells.

While the body has built-in defenses for natural particles it encounters, the danger ofnanotechnology is that it is introducing entirely new type of particles. Particles some experts say the body is likely to find toxic.

Highest at risk are workers employed by manufacturers producing products that contain nanoparticles. The National Institute for Occupational Safety and Health  reports over 2 million Americans are exposed to high levels of nanoparticles and they believe this figure will rise to 4 million in the near future. NIOSH publishes safety guidelines and other information for those employed in the nanoindustry.

There is no doubt that nanoparticles have interesting and useful properties. That said, many groups propose a moratorium on marketing and urge research to precede manufacturing rather than proceed it. Strong economic drives and competition in the marketplace may be taking precedence over methodical scientific prudence when it comes to public health and possible dangers of nanotechnology.

Some have compared the situation to that of asbestos dust -- another material that was assumed safe until it was learned that it can cause cancer from accumulation in the body. Today 3,000 deaths per year are still attributed to asbestos from decades-old use. Those concerned with possible dangers of nanotechnology wish to avoid a similar or even worse scenario down the road, especially considering the growing market for nanoparticles in such diverse products as car paint, tennis rackets, and make-up.

Nanotechnology should not be confused with molecular nanotechnology  a still theoretical science dedicated to manufacturing products from the atom up through use of nanoscale machines. MNT is spearheaded by physicist Dr. Eric Drexler, who coined the term, "nanotechnology" and later, "molecular nanotechnology."

Nanotechnology in everyday life

From the clothes and sunglasses you wear to computer hard drives and even cleaning products, nanotechnology – often inspired by the natural world – plays a big part in the manufacture of many familiar products

You're going on holiday. Off the plane and checked into your hotel, you don the wrinkle-free shirt you packed so you wouldn't have to do any ironing. Grabbing your scratch-resistant sunglasses and your sunscreen you dash to the hotel pool, not forgetting to pick up your camera phone so you can send that boastful photo home. Poolside, you relax listening to summery tunes on your MP3 player, before taking a plunge into the cool refreshing water.

As you soak up the sun, nanotechnology is probably the furthest thing from your mind. Yet throughout every step of your trip you've unknowingly encountered it. From the nanoparticles that coated the surface of your plane to reduce drag, to the way the hotel pool was cleaned, nanotechnology was there. It boosted your sunscreen's ability to reflect harmful ultraviolet radiation, rendered your shirt with that just-ironed look and armoured your designer shades against unwanted scratches. Your gadgets also used nanotechnology to store your snaps and songs on their respective hard-drives and flash memory.

Nanotechnology is an inescapable part of modern everyday life, both on holiday and at home. "There are things we've been using for a long time which contain nanosize components, like the lasers in DVD and CD players," says Milo Shaffer, head of the London Centre for Nanotechnology. Yet most of the time it goes unnoticed. "On the whole people aren't very aware of the nanotechnology all around them," Shaffer explains.

So if you stretch out an arm you'll almost certainly be able to grab something that employs nanotechnology. But you might also be breathing in nanoparticles that have been around for many years. Ultrafine particles (UFPs) are airborne nanoscale materials that originate from many sources, including traffic pollution. UFPs can deposit in your lungs with the potential to cause respiratory problems including asthma and lung disease.

Although not all nanotech is the result of human activity, evolution has had at least a 3bn-year head-start when it comes to manipulating materials on the smallest scales. "Nature is all about nanoscale structures. It starts with the cell," explains Julian Vincent, a former biologist and now professor of mechanical engineering at the University of Bath. "Biology plays around with the molecular scale all the time, it's the level at which all biological reactions occur," he adds.

Silk is a prime example of naturally occurring nanotechnology. "Silk is strong because of the way its molecules are aligned into a set of cross-links," says Vincent. Kevlar, used in everything from flak-jackets to frying pans, was constructed by engineering its constituent molecules in a similar fashion.

Mimicking nature's nanotech is becoming big business. Teams of researchers have turned to geckos and mussels in order to develop adhesives that bind to dry and wet surfaces alike. They've drawn inspiration from nanofibres in the geckos' foot hairs, which allow the lizards to cling upside down on inclined surfaces, and the nanoscale structures used by mussels to "glue" themselves to rocks despite being underwater.

Similarly, non-reflective materials have been improved by imitating the nanostructures found in the wings of cicada insects. Their wings contain small projections, spaced about 200 nanometres (a nanometre is equivalent to one billionth of a metre) apart, which allow 98% of light to pass through them. Nanostructures are also responsible for the brilliant white colouring of the cyphochilus beetle. The arrangement of molecules within the beetle's scales scatter almost all incoming light. Mimicking this molecular arrangement in made-made materials would eliminate the need for potentially toxic pigments, which are often currently used to create white paint and paper.

Plants too are big exploiters of natural nanotech. Nanostructures on the surface of lotus leaves repel water which carries away dirt as it rolls off the leaf, allowing the lotus to remain spotless despite growing in muddy water. This "lotus effect" is the basis behind self-cleaning windows. But rather than shedding water, beetles in the Namib desert are using a series of alternating waxy and non-waxy nanostructures to capture precious moisture from the early morning fog. Applying the idea to buildings could allow them to trap moisture for use inside.

Whether in your office, home or while sunning yourself on holiday, it is impossible not to encounter technology based on the manipulation of the very small. Many technologies in the modern world rely on nanostructures, often inspired by evolution in the natural world. But there is much untapped potential left to explore. "The overlap between the way nature solves these problems and the way we do, using technical solutions, is only 10-20%," Vincent explains. "I'd like to see a world where we can truly utilise the tried and tested methods nature has employed," he says.