Environmental Science 15th Edition by Scott Spoolman,Tyler Miller

Exercise 7

THE NANOTECHNOLOGY REVOLUTION
N anotechnology , or tiny tech, uses science and engineering to manipulate and create materials out of atoms and molecules at the ultra-small scale of less than 100 nanometers. The diameter of the period at the end of this sentence is about a half million nanometers.
At the nanometer level, conventional materials have unconventional and unexpected properties. For example, scientists have learned to link carbon atoms together to form carbon nanotubes that are 60 times stronger than high-grade steel. An incredibly thin and nearly invisible thread of this material is strong enough to suspend a pickup truck. Using carbon nanotubes to build cars would make them stronger and safer and would improve gas mileage by making them up to 80% lighter.
Currently, nanomaterials are used in more than 1,300 consumer products and the number is growing rapidly. Such products include certain batteries, stain-resistant and wrinkle-free clothes, odor-eating socks, self-cleaning glass surfaces and exterior surfaces on buildings, self-cleaning sinks and toilets, sunscreens, waterproof coatings for cell phones and other electrical devices, some cosmetics, some processed foods, and food containers that release nanosilver ions to kill bacteria, molds, and fungi. A new one-atom thick nanotextile material that can conduct electricity could be incorporated into clothing, and this could allow you to charge your cellphone or start your laptop using solar energy by plugging it into your jeans or your tee shirt. In 2014, Swedish scientists developed a paper filter made of cellulose nanofibers that can remove viruses from drinking water.
Nanotechnologists envision technological innovations such as a supercomputer smaller than a grain of rice, thin and flexible solar cell films that could be attached to or painted onto almost any surface, motors smaller than a human cell, biocomposite materials that would make our bones and tendons super strong, nanovessels filled with medicines that could be delivered to cells anywhere in the body, and nanomolecules specifically designed to seek out and kill cancer cells. Computercontrolled tabletop nanofactories could produce items from computerized blueprints within minutes. Nanotechnology would allow us make materials from the bottom up, using atoms of abundant elements (primarily hydrogen, oxygen, nitrogen, carbon, silicon, and aluminum) as substitutes for scarcer elements, such as copper, cobalt, nickel, and tin, to make a wide variety of products.
Nanotechnology has many potential environmental benefits. Designing and building existing and new products from the molecular level up would greatly reduce the need to mine many materials. It would also require less material and energy and reduce waste production. We may be able to use nanoparticles to remove industrial pollutants in contaminated air, soil, and groundwater. Nanofilters might someday be used to desalinate and purify seawater at an affordable cost, thereby helping to increase drinking water supplies. GREEN CAREER: Environmental nanotechnology
So what's the catch? The main problem is serious concerns about the possible harmful health effects of nanotechnology on humans. The tiny size and large combined surface area of the huge numbers of these nanoparticles involved in any particular application make them more chemically reactive and potentially more toxic to humans and other animals than are conventional materials composed of much larger particles. Laboratory studies involving mice and other test animals reveal that nanoparticles can
•be inhaled deeply into the lungs and absorbed into the bloodstream and can penetrate cell membranes, including those in the brain;
•move across the placenta from a mother to her fetus and can move from the nasal passage to the brain;
•result in lung damage similar to that caused by mesothelioma, a deadly cancer resulting from the inhalation of asbestos particles; and
•cause changes in the rate and rhythm of a rodent's heartbeat, similar to such changes caused by heart disease.
We know far too little about these and other risks at a time when the use of untested, unregulated, and unlabeled nanoparticles is growing rapidly. An expert panel from the U.S. National Academy of Sciences has said that the U.S. government is not doing enough to evaluate the potential health and environmental risks of using engineered nanomaterials. For example, the U.S. Food and Drug Administration does not even maintain a list of the food products and cosmetics that contain nanomaterials.
By contrast, the European Union (EU) takes a precautionary approach to the use of nanomaterials and other untested chemicals. While U.S. regulators generally assume that nanoparticles and chemicals are innocent until shown to be harmful, EU laws require that manufacturers demonstrate the safety of their products before they can enter the marketplace.
Many analysts say we need to take three steps before unleashing nanotechnology more broadly. First, greatly increase research on the potential harmful health effects of nanoparticles. Second, develop guidelines and regulations for controlling its growing applications until we know more about the potentially harmful effects of this new technology. Third, require labeling of all products containing nanoparticles.
Critical Thinking
Do you think the potential benefits of nanotechnology products outweigh their potentially harmful effects? Explain.