[Rachel’s introduction: Across the country, schools, parks, and private sports organizations are installing the “new generation” synthetic turf. It is springier than the old AstroTurf and feels more like natural grass. But it is made from used tires, which contain toxic chemicals.]

By William Crain and Junfeng (Jim) Zhang

Across the country, schools, parks, and private sports organizations are installing the “new generation” synthetic turf. It is springier than the old AstroTurf and feels more like natural grass. However, the new turf is being installed before there has been thorough research on its potential health risks. Fortunately, increasing numbers of research agencies are conducting studies. But as we shall see, the studies are often limited and reach premature conclusions about the turf’s safety.

Presence of Hazardous Chemicals

Of special concern are the small rubber granules that rest between the turf’s plastic blades of grass. These granules, which are the size of grains of rice or smaller (0.5 to 3 mm), contribute to the turf’s resiliency. The granules are typically made from large quantities of recycled rubber tires; between 25,000 and 40,000 scrap tires are used to produce the granules for a standard soccer field.[1]

Although the tiny granules (sometimes called the “infill”) lie between the plastic blades of grass, they also are common on the surface, so children and athletes come into frequent contact with them. In fact, many players have told us that the granules get into their shoes and wind up in their homes. When we learned that the granules are so accessible to park users, we decided to test samples of the granules to see if contained toxic chemicals found in scrap tires. Specifically, we wondered if they contained any of 15 polycyclic aromatic hydrocarbons (PAHs) on the U.S. Environmental Protection Agency priority pollutant list or heavy metals that also can have toxic effects.

Our first preliminary study[2] analyzed two samples of granules from a New York City Park. The analyses revealed six PAHs at concentrations sufficiently high that the New York State Department of Environmental Conservation (DEC) would have required their removal if the PAHs had been in contaminated soil sites. The six PAHs were: benzo(a) anthracene, chrysene, benzo(b)fluoranthene, benzo(a)pyrene, benzo(k) fluoranthene, and dibenzo(a,h)anthracene. All six are likely to be carcinogenic to humans.[3]

We also conducted follow-up analyses of granules from two other New York City Parks, gathering two samples from one park and one sample from the other park. We detected three of the same PAHs at elevated levels in at least one of the samples. A particularly hazardous PAH — dibenzo(a,h)anthracene — exceeded the DEC soil standard in all three samples.[4] The results of our studies generally conform to those of the Norwegian Building Research Institute.[5]

We also found that the granules contained worrisome levels of zinc and lead.[2] These metals also been detected in research by others, including the Norwegian Building Research Institute[5] and the Rochesterians Against the Misuse of Pesticides (RAMP).[6] Zinc isn’t necessarily harmful. In fact, we need some zinc, and it is included in multivitamin pills. But excessive zinc produces problems such as stomach cramps and anemia in humans.[7]

Although the detected levels of lead have generally been below contaminated site soil standards set by the New York Department of Environmental Conservation (DEC), many health scientists warn against adding any lead at all to the environment, for even small amounts can contribute to neurocognitive problems in children.[8]

These preliminary studies only indicated that toxicants are present in the rubber granules. The more critical question concerns the bioavailability of the toxicants: Can they leach into the surrounding environment and harm human and non-human organisms? Can they be absorbed into the bodies of children and athletes who use the turf fields?

Leaching into Water and Soil

Numerous studies have demonstrated that chemicals in whole tires, tire shreds, and recycled tire crumbs can leach into water and soil.[9-12] In addition, many of these studies have demonstrated that the chemicals harm or kill aquatic life, including algae, minnows, trout, and frogs.[13] The chemicals also can stunt the growth of land plants.[13] Researchers have been slower to identify precisely which chemicals in the rubber produce the toxic effects, but researchers generally believe that the culprits include metals such as zinc.[9, 13] One investigation implicated PAHs in the death of trout where rubber tires had been placed in water.[14]

Two studies specifically asked what happens when synthetic turf granules are placed in water, and both studies found that considerable zinc was released.[10,11] In a widely cited report funded by a Candadian tire recycling agency, Birkholz and his colleagues[15] discovered that ground-up rubber from a flat playground surface killed aquatic life. Birkholz emphasized that that rubber material was less toxic if it had been on the playground for more than three months, but the effects of ageing merit further study; zinc might actually be released in greater quantities after a few years, as the rubber degrades.[10]

Noting that most of the research on damage to non-human organisms has been conducted in the laboratory, a report by California’s Office of Environmental Health Hazard Assessment (OEHHA) concludes that there is little risk in real-life, outdoor conditions. Specifically, the OEHHA concludes that “during rain events” the recycled tire material in play areas is unlikely to leach toxic chemicals in high enough concentrations to harm aquatic life.[16] But the OEHHA’s conclusion is speculative; it only cites one study that supports its view. What’s more, the study it cites only examined how water quality was affected by a tire trench — not the tiny rubber particles in synthetic turf that move about and can potentially flow into streams and bodies of water. A study by FieldTurf Tarkett (Nanterre, France) and French research agencies also questions the potential harm of leaching, but FieldTurf Tarkett is the world’s largest manufacturer of synthetic turf, so it’s difficult to assess its findings.[17] A recent Dutch investigation reaches the more sober conclusion that “the leaching of zinc is a major concern.”[18]

Toxic chemicals in rubber material might also leach into human drinking water. So far, the research on this possibility is sparse. The OEHHA report observes evidence of increased quantities of toxic chemicals in groundwater, but the report emphasizes that the contaminants hadn’t spread more than a few meters from the rubber sites.[19]

We will now turn to the possibility that the toxicants in recycled rubber can be absorbed by children and athletes from play on synthetic turf surfaces.


In their widely cited report, Birkholz et al. maintained that inhalation in not “a plausible route of exposure because no volatile compounds would be expected to remain in the shredded, solid material.”[20] But as Brown[21] observes, this speculation has turned out to be incorrect. The Connecticut Agricultural Experiment Station recently found that at 60 deg. C (140 deg. F) — a temperature that synthetic turf reaches in the summer — the rubber granules off-gassed several hazardous volatile organic compounds (VOCs) into the air.[11] Three chemicals — benzothiazole, n-hexadecane, and 4-(t-octyl) phenol — are irritants to humans; a fourth chemical, butylated hydroxyanisole, has many toxic effects and may be carcinogenic to humans.[22] In addition, in 2006 the Norwegian Institute of Public Health and Radium Hospital observed that several VOCs were released from rubber granules in an indoor facility.[23] Others, including RAMP, also have detected VOCS.[5,6] Although the Norwegian Institute — as well as the FieldTurf/French agencies[17] — play down the possibility that the chemicals would remain in the air sufficiently long to cause harm, more research on this question is needed. Research also is needed on the extent to which rubber granules produce particulate matter that aggravates asthma.[21]


Because children’s bodies are still developing, they are especially vulnerable to the damaging effects of toxic exposures. Infants and toddlers are also uniquely susceptible to exposure through ingestion because they like to put objects into their mouths.[24] When parents watch games from the sidelines, they frequently let their young children crawl about on the turf nearby, and the children might pick up and swallow the rubber granules. Infants and toddlers also might ingest the granules that wind up in their homes after the games.

Birkholz et al.[15] evaluated the possibility that the ingested crumb material from flat rubber playground surfaces produces cancer. Based on the results of in vitro genotoxicity assays, Birkholz et al. concluded that the risk is negligible; substances extracted from shredded rubber did not damage DNA or chromosomes. However, the investigators did not specify the potentially harmful chemicals they tested. In addition, the fact that the research was funded by the tire recycling industry raises questions in the minds of many.

OEHHA, whose research was commissioned by the State of California, examined the extent to which metals, PAHs, and VOCs might be absorbed through the digestive system. Simulating the environment of the human stomach, the researchers concluded that risks to human health are de minimis.[25] But as Brown[26] notes, the researchers explored only the acute effect of a single ingestion. The researchers acknowledged that if a child ingested some chemicals repeatedly, the results might be different. Their data suggest that the ingestion of several metals, including lead, is of particular concern.

Moreover, the OEHHA investigators only simulated the stomach environment. There is a need to simulate the digestive process more completely — to include the enzymatic actions of saliva and intestinal fluid as well.

Skin Contact

The results from studies of skin contact are ambiguous. In their main study of dermal exposure, the OEHHA researchers[27] found that one PAH, chrysene, can be absorbed from a playground rubber surface onto a polyester wipe. The authors then estimated that if children engaged in considerable hand contact with the rubber over several years — and sometimes put their hands in their mouths — the children would experience an increased cancer risk. This conclusion is based on a fair amount of speculation, but it alerts us to a danger.

In a 2005 study in Denmark, Nilsson et al. placed synthetic perspiration on a tractor tire for one hour but failed to find that any PAHs gravitated to the liquid.[28] However, this study, like the OEHHA research on dermal exposure, examined relatively large rubber surfaces (a playground surface and a tire). The results derived from this approach can be misleading when the actual dermal contact occurs with the tiny rubber granules in synthetic turf. Tiny particles have proportionately larger surface areas. Consequently, toxic chemicals contained in the small granules may be more readily absorbed through ingestion or skin contact.

A recent Netherlands study[10] examined the urine of football players after they had “intensive skin contact with rubber crumb on an artificial field pitch.” The urine tests did not “unambiguously” indicate that PAHs had entered the athletes’ bodies. Although this is important information, similar research needs to be repeated under a variety of playing conditions and include children.

In Korea, teachers have noticed nose and eye irritation among school children playing on artificial turf surfaces.[29] Others have called for research how dermal contact with rubber infill might cause allergic reactions.[10]


Hazardous chemicals are clearly present in synthetic turf rubber granules that are made from recycled tires. Some metals in the granules, including zinc, leach into water and, if they behave like the metals in other rubber tire material, they can kill aquatic life. However, it is not yet clear whether this leaching presents a health risk to humans and other species in ordinary life conditions. It also is unclear whether the various toxic chemicals in the rubber granules can be absorbed into the bodies of children and athletes through inhalation, ingestion, or skin contact. Much more research is needed. Although some reports have concluded that the risks are minimal, such conclusions are premature.


[1] A New Turf War: Synthetic Turf in New York City Parks. Special report, New Yorkers for Parks, Spring, 2006, p. 7. See also FieldTurf Tarkett, Debunking the Myth of SBR Dangers, p. 2.

[2] Crain, W., and J. Zhang. Hazardous Chemicals in Synthetic Turf. Rachel’s Democracy and Health News, #873, Sept. 21, 2006.

[3] International Agency for Research on Cancer (IARC) Monographs on the Evaluation of Carcinogenic Risk to Humans, PAHs, Vol. 95, 2006.

[4] Crain, W., and J. Zhang. Hazardous Chemicals in Synthetic Turf: Follow-up Analyses. Rachel’s Democracy and Health News, #902, April 12, 2007.

[5] Plesser, T. S. W., and O. J. Lund. Potential health and environmental effects linked to artificial turf systems — final report. Norwegian Building Research Institute (report to the Norwegian Football Association), 2004.

[6] Rochesterians Against the Misuse of Pesticides. Synthetic Turf Chemicals, 2007.

[7] ATSDR, ToxFAQs for Zinc, August 2005.

[8] Canfield, R.L., Henderson, C.R., Cory-Slechta, D.A., Cox, C., Jusko, T.A., and Lanphear, B.P. Intellectual impairment in children with blood lead concentrations below 10 micrograms per deciliter. New England Journal of Medicine, 348, 2003, pp. 1417-1526. Landrigan, P. Testimony to the U.S. Senate Committee on Environment and Public Works, Washington, DC, Oct. 1, 2002.

[9] Office of Environmental Health Hazard Assessment (OEHHA), Evaluation of health effects of recycled waste tires in playground and track products. Contractor’s report to the Integrated Waste Management Board, State of California (Publication #622-06-013), January, 2007, pp. 2, 91, 97.

[10] Hofstra, U. Environmental and Health Risks of Rubber Infill. Summary. INTRON, The Netherlands, February 9, 2007.

[11] Mattina, M. J., M. Isleyen, W. Berger, and S. Ozdemir. Examination of crumb rubber produced from recycled tires. The Connecticut Agricultural Experiment Station, 123 Huntington St., New Haven, CT 06504. Telephone 203-974-8449.

[12] Chalker-Scott, L. The myth of rubberized landscapes. Puyallup Research and Extension Center, Washington State University.

[13] OEHHA (see reference 9), pp. 97-102.

[14] Stephenson, E, M. Adolfsson-Erici, et al. Biomarker responses and chemical analyses in fish indicate leakage of polycyclic aromatic hydrocarbons and other compounds from car tire rubber. Environmental Toxicology and Chemistry, 22, 2003, 2926-2931.

[15] Birkholz, D. A., K. L Belton, and T. L. Guldotti. Toxicological evaluation for the hazard assessment of tire crumb for use in public playgrounds. J. Air & Waste Manage. Assoc., Volume 53, July 2003, p. 904.

[16] OEHHA (see reference 9), p. 2.

[17] Moretto, R. Environmental and health evaluation of elastomer granules (virgin and from used tires) on filling in third-generation artificial turf. Research by FieldTurf Tarkett, Aliapur, and Ademe, France, 2007.

[18] Hofstra, U. (see reference 10), p. 5.

[19] OEHHA (see reference 9), p. 95.

[20] Birkholz et al. (see reference 14), p. 904.

[21] Brown, D. Exposures to recycled rubber crumbs used on synthetic turf fields, playgrounds, and as gardening mulch. Environment and Human Health, Inc., August, 2007, p. 23.

[22] Brown (see reference 21), p. 8.

[23] Bjorge, C. Norwegian Public Health Report, Artificial Turf Pitches — An Assessment of the Health Risks for Football Players, Prepared by Norwegian Institute of Public Health and the Radium Hospital, Oslo, January 2006.

[24] Landrigan, P. (see reference 8).

[25] OEHHA (see reference 8), Ch. 6.

[26] Brown (see reference 21), p. 12.

[27] OEHHA (see reference 8), Ch. 7.

[28] Nilsson, N. H., A. Fielberg, and K. Pommer. Emission and evaluation of health effects of PAHs and aromatic amines. Survey of Chemical Substances in Consumer Products, no.54. [8 Mbyte PDF] Danish Ministry of the Environment, 2005.

[29] Brown (see reference 21), p. 20.

Authors’ affiliations

William Crain, Ph.D., is professor of psychology at The City College of New York and president of Citizens for a Green Riverside Park. Billcrain@aol.com

Junfeng (Jim) Zhang, Ph.D. is professor and acting chair, Department of Environmental and Occupational Health, the School of Public Health, the University of Medicine and Dentistry of New Jersey and Rutgers University. jjzhang@eohsi.rutgers.edu


From: Harper’s Magazine (pg. 78)
October 1, 2007


[Rachel’s introduction: Europe has replaced the U.S. as the leader in regulating chemicals; as a result European manufacturers are gaining a competitive advantage over American companies.]

By Mark Schapiro

In the late 1990s, citizens of several European countries learned from newspaper reports that their infants were constantly being exposed to a host of toxic chemicals. Babies were sleeping in pajamas treated with cancer-causing flame retardants; they were sucking on bottles laced with plastic additives believed to alter hormones; their diapers were glued together with nerve-damaging toxins normally used to kill algae on the hulls of ships. When European health officials tried to look into the matter, they were confounded by how little they actually knew about these and other potentially hazardous chemicals. Regulators discovered that they had no way of assessing the dangers of long-term exposure to everyday products. Some manufacturers of baby goods did not even know what was in their own products, since chemical producers were under no obligation to tell them. Such data, if it existed at all, was secreted away in the vaults of chemical companies and had never been submitted to any government authority.

In the years since those news reports, the nascent science of hio- monitoring has provided further insight into how the industrial chemicals that are in clothes, food packaging, cosmetics, toys, electronics, and just about every modern convenience are actually lodging in the human body. Greenpeace U.K. released a study in 2005 that found numerous toxic chemicals in the umbilical-cord blood of European infants. That same year, World Wildlife Fund International tested the blood of three generations of women from twelve European countries. The largest number of chemicals — sixty-three — was found in the group of grandmothers. Given the number of years they had had to accumulate exposure, this result was perhaps not surprising. But the next-highest level was among their grandchildren, aged twelve to twenty-eight, who in their short lifetimes had amassed fifty-nine different toxic chemicals. The blood of a nineteen-year-old Italian, who later sent me her test results, included brominated flame retardants, which are potential liver, thyroid, and neurological toxins that are used to coat many electronics; the pesticides DDT and lindane, the latter of which is suspected of contributing to breast and other cancers; perfluorinated chemicals, known carcinogens that are used as stain- and water-repellents on clothing, furniture, and non-stick cookware; and artificial musk aromas, found in soaps and perfumes, that scientists claim can reduce the body’s ability to expel other toxins.

Bio-monitoring tests in the United States have revealed the same dangerous chemicals making their way into the blood of Americans. In 2005, the Centers for Disease Control and Prevention completed screening for the presence of 148 toxic chemicals in the blood of a broad cross section of Americans; it found that the vast majority of subjects harbored almost all the toxins. In the same year, the CDC’s National Survey on Family Growth concluded that rates of infertility were rising for women under the age of twenty-five, a spike many scientists attribute, at least in part, to routine exposure to toxic chemicals. The Environmental Working Group conducted tests on the umbilical cords of ten newborns in 2006 and discovered that cancer- causing, endocrine- disrupting, and gene-mutating chemicals had passed from the mothers to their fetuses through the placenta.

Up until the 1970s, no country had imposed any meaningful oversight of the tens of thousands of chemicals that had entered the marketplace since World War II. Then, in 1976, the U.S. Congress passed the Toxic Substances Control Act (TSCA), which granted the government the authority to track industrial chemicals and to place restrictions on any that proved harmful to humans or the environment. Because the United States was the world’s preeminent economic power, other major chemical producers — Germany, France, and Britain — soon brought their national regulations into line with TSCA so as not to lose the U.S. market. Shortly thereafter, Japan and other countries hoping to conduct trade with the West also had to adopt the central principles of the law as their own. Thus, America set the rules for chemical regulation across the globe.

But TSCA came with an enormous loophole, a caveat leveraged into it by the powerful chemical industry: every chemical already on the market before 1979 was exempted from the law’s primary screening requirements. Three decades after TSCA came into being, 95 percent of all chemicals in circulation have never undergone any testing for toxicity or their impact on the environment. The extent to which TSCA has failed to regulate hazardous substances is now evident in the bio- monitoring results in Europe and America.

Europeans have recently decided to do something about all the untested chemicals that are ending up in their blood. “The assumption among Americans is, “If it’s on the market, it’s okay,” explained Robert Donkers, an E.U. official who was asked to review Europe’s regulatory laws after the baby-product scare. “That fantasy is gone in Europe.” Donkers’s efforts were the first steps in what became, seven years later, a new E.U. chemical regulation called REACH — Registration, Evaluation and Authorisation of Chemicals. REACH amounts to a revolution in how chemicals are managed, and in how production decisions around the world will be made from now on. Regulations set by the most powerful countries have quickly become, through trade, the international standard. And the European Union, with a market of 480 million people stretching across twenty-seven countries, is now significantly larger than the United States in both population and wealth; Europe’s gross national product surged past that of the United States in 2005, and the gap increased when two more countries joined the E.U. earlier this year. The E.U. is now the most significant trading partner for every continent except Australia. The ripple effects from this shift in economic power have been one of the great untold stories of the new century.

Indeed, Europe is now compelling other nations’ manufacturers to conform to regulations that are far more protective of people’s health than those in the United States. Europe has emerged not only as the world’s leading economic power but also as one of its moral leaders. Those roles were once filled by the United States.

When TSCA took effect in the late 1970s, the United States was seen as a pioneer of health and environmental regulation. The Environmental Protection Agency had been established only a few years before, and the government had recently set standards for fuel economy, hazardous- waste disposal, and many other factors affecting the country’s air and water quality. Currently, some 42 billion pounds of chemicals are produced in or brought to America each day, but because of TSCA exemptions, fewer than 200 of all the chemicals on the market have ever under-gone any serious risk assessments. Among the 62,000 chemicals the act excused from testing or review were thousands of highly toxic substances, such as ethyl benzene, a widely used industrial solvent suspected of being a potent neurotoxin; whole families of synthetic plastics that are potential carcinogens and endocrine disrupters; and numerous other chemicals for which there was little or no information.

The EPA is actually allowed to place restrictions on the chemicals grandfathered onto the market if the substances present an “unreasonable risk to human health.” In order to demonstrate this risk, however, the agency must surmount tremendous legal and administrative obstacles. The EPA is required to weigh the “costs to industry” of any regulation, and it is obliged to impose restrictions that are the “least burdensome” to chemical manufacturers. According to a 2005 Government Accountability Office analysis, the EPA relies too heavily on industry test data when making safety assessments and allows companies to keep critical data from the public through “indiscriminate” claims that information is proprietary. Even for those few new chemicals brought to market after TSCA, the screening record is not reassuring. Ninety days before commercial-scale production of a chemical begins, manufacturers are required to provide the EPA with all exposure and toxicity data. Theoretically, this information enables the agency to determine whether regulatory action is warranted before chemicals hit the market. But according to the EPA’s own figures, 85 percent of the notifications submitted contain no health data.

One result of this industry-friendly screening is that the EPA has banned only five chemicals since its inception in 1970. For a brief time the banned list included a sixth substance: asbestos. In 1989, the EPA prohibited nearly all uses of asbestos, which it classified as a “known carcinogen.” The chemical industry challenged the agency, however, and in 1990 a federal court vacated the ban, asserting that the EPA had neither met TSCA’s requirement that the conclusive dangers of the chemical should exceed its perceived usefulness nor demonstrated that the ban was the “least burdensome alternative” for eliminating the “unreasonable risk” of exposure. The EPA has not acted to ban a chemical since that decision, even though other countries have outlawed asbestos and numerous toxins that are still in use in the United States. (Since 2004, the E.U. has banned entire categories of hazardous chemicals from use in cosmetics, toys, electronics, and other consumer goods.) By making it easier to hang on to old chemicals than to develop new ones, TSCA provides no incentive for manufacturers to create less toxic alternatives. The absence of even minimal toxicity data insulates the industry from the normal supply-demand dynamic of the market; consumers, in other words, have no means of expressing their potential preference for a less toxic substitute. Chemical companies have spent lavishly to preserve these lax standards. Since 1996, the industry has contributed $47 million to federal election campaigns, and it pays about $30 million each year to lobbyists in Washington. Lynn Goldman, who served as assistant administrator for toxic substances at the EPA from 1993 to 1998, told me that she and her colleagues knew TSCA was largely ineffectual. “There were thousands of chemicals out there, and we didn’t know what they were. We weren’t able to get the data, weren’t able to assess the risks, nothing.” Goldman recalls a party held in Washington to commemorate TSCA’s twentieth anniversary. “Someone from the chemical industry got up to salute TSCA and said, ‘This is the perfect statute. I wish every law could be like TSCA.'”

The primary target of Europe’s new chemical regulation is the more than 60,000 compounds TSCA allowed to stay on the market without testing. Under REACH, these chemicals will have to he registered, evaluated for toxicity, and authorized before being permitted to remain in use. Fifteen hundred chemicals are expected to be placed on a 2008 list of “substances of very high concern.” These toxins, which are known to cause cancer, alter genes, and affect fertility, will be the first to be removed from the market unless producers are able to prove that they can be “adequately controlled.” In addition to assessing chemicals in their raw form, REACH also extends to the endless array of consumer goods that utilize these compounds; thus, tens of thousands of “downstream users,” from construction companies to tennis-shoe manufacturers and fashion houses, will be forced to find out and report what chemicals are in their products and what effects they have on human health and the environment.

By the end of 2008, the first sets of risk data are to be submitted to the E.U. Manufacturers will then have ten more years to complete what amounts to a scientific cataloguing of the chemical makeup of the global economy. Whereas U.S. regulators are forced to find scientifically improbable definitive evidence of toxic exposure before acting, REACH acts on the basis of precaution. European authorities consider the inherent toxicity of a substance and, based on an accumulation of evidence, determine whether its potential to cause harm is great enough to remove it from circulation. Unlike TSCA, REACH places the burden of proof on manufacturers, who must demonstrate that their chemicals can he used safely. The law also proposes to drastically limit the amount of health-related data that companies can claim as proprietary.

Critics of stricter chemical regulations have long contended that the price of compliance would be far too steep. But the E.U. estimated that REACH would cost European chemical manufacturers about $4 billion over fourteen years — a figure that amounts to less than 1 percent of their combined yearly revenue. The E.U. further calculated that these expenses would be repaid many times over by the resulting health benefits. According to their figures, REACH would prevent some 4,500 occupational cancer cases each year and reduce European health-care costs from ailments related to chemical exposure by $69 billion over the next three decades. Moreover, by establishing what will be the first open, actually free market in chemicals, in which informed consumers will be able to make decisions as to what risks they are willing to take, REACH promotes new research into the development of safer chemicals. Chemists have already come up with substitutes for some of the most problematic toxic chemicals on the market, and the E.U. estimates that its environmental initiatives have spawned billions of dollars in “green” industries and technologies.

U.S. companies could be put at a serious competitive disadvantage if they do not acknowledge the changes taking place across the Atlantic. Americans are already losing ground to Europeans in the chemical business, having slipped in the past decade from a trade surplus with European manufacturers to a more than $28 billion deficit.

That deficit promises to increase as environmentally aware consumers are given the opportunity to choose between European goods with chemicals that have undergone toxicity screening and American goods with unscreened chemicals. Because American companies interested in exporting to the E.U. will also have to supply toxicity data to the European authorities, REACH does present opportunities for U.S. consumers. Not only will these chemicals he subject to their first- ever health- and environmental-impact review but the findings will then be available on the European Chemical Agency’s website. At that point, U.S. consumers may no longer choose to use untested American goods.

The American public, along with the American media, has so far been mostly oblivious to the new chemical regulations coming out of Europe. The Bush Administration and U.S. manufacturers, however, have been fixated on it for years. REACH is far more than just another foreign ban of a specific chemical with which U.S. industry will have to contend; it strikes at the fundamental belief that the United States decides what can and cannot be contained in the goods sold all over the world. So as REACH was being debated in the European Parliament from 2003 to 2006, the U.S. government and the nation’s industries teamed up to undertake an unprecedented international lobbying effort to kill or radically weaken the proposal.

The assault came from an assortment of government and industry offices. A memo that circulated at the State Department’s Bureau of European and Eurasian Affairs denounced REACH as too “costly, burdensome, and complex” for industry to follow. If chemicals were put through the rigors of review, a Commerce Department brief warned, “hundreds of thousands of Americans could be thrown out of their jobs.” U.S. Trade Representative Robert Zoellick submitted a protest to the World Trade Organization asserting that REACH amounted to a “non-tariff” barrier to foreign exporters. A delegation of State Department officials joined two Dow Chemical executives in Athens to lobby the Greeks, who then held the presidency of the European Union. Colin Powell himself sent out a seven-page cable to U.S. embassies throughout the world claiming that REACH “could present obstacles to trade” and cost American chemical producers tens of billions of dollars in lost exports. At the same time, Washington sent emissaries to such new E.U. members as Hungary, Poland, Estonia, and the Czech Republic-formerly Communist countries where environmental consciousness was far less developed than in Western Europe — in an effort to peel off support within the E.U. by claiming that REACH would hurt European firms competing in foreign markets. The State Department also recruited a coalition of allies to oppose REACH from countries heavily reliant on exports; pleas went out to Brazil, India, Japan, Malaysia, South Africa, and others to develop a “coordinated outreach” strategy among “E.U. trading partners.” In E.U. parliamentary hearings on REACH that I attended, I was able to identify lobbyists not only for the U.S. and European chemical industries but also for such downstream chemical users as cement, automobile, textile, and pharmaceutical companies.

The U.S. lobbying effort amounted to an historic intrusion into European affairs. Robert Donkers, who in 2003 was stationed in the United States to explain REACH to Americans, invited me to consider the reverse scenario: European officials descending on Washington to lobby against a hill being considered in Congress. “It wouldn’t he tolerated,” he said. “We wouldn’t last ten minutes!” By early 2006, REACH had already undergone a rewrite by the European Commission and had passed its first reading in the parliament.

Nearly a thousand amendments had been voted on and consolidated. Environmentalists in Europe felt the standards had already been weakened in significant ways. Priority had been put on “high-volume chemicals” produced in excess of a thousand tons a year, with diminishing data requirements as the volume declined; broad exemptions were issued for certain plastics. But REACH still retained its core principles: that thousands of existing chemicals would be reviewed for their toxicity, that the data from those reviews would be made public, and that responsibility for demonstrating a chemical’s safety would rest with the manufacturers.

In Washington, however, President Bush signaled that the struggle was far from over. He sent C. Boyden Gray to Brussels in February as the new U.S. ambassador to the E.U. A veteran Republican operative and an heir to the R. J. Reynolds tobacco fortune, Gray had spent a career in and out of government rewriting the rules of environmental oversight to reduce the burden on business. As general counsel to the first President Bush, he helped transform how the EPA and other federal agencies were managed so that cost-benefit analyses would be given precedence over risk-based decisions. “This is the beast we have confined and tamed,” he told me, referring to his success in limiting U.S. regulatory laws.

One of Gray’s first public undertakings as ambassador began at AmCham E.U., an affiliate of the U.S. Chamber of Commerce in Brussels. Am- Cham E.U. lobbies the E.U. on behalf of 140 U.S. companies, including Apple, Boeing, Dow, DuPont, General Motors, and McDonald’s. Environmental policies are one of their top concerns. In June 2006, Gray orchestrated a joint press release, from the United States and twelve other countries, that objected to REACH’s hazard- based system for assessing risks and called for weakening its registration requirements. That press release, it turns out, was written at the offices of AmCham E.U. and sent from the U.S. Mission in Brussels. One morning that June, I received a leaked copy of the original draft, which, thanks to Microsoft tracking software, included the editorial changes that were written into the document as it made its way through various readers. Where AmCham E.U.’s address had once been now ran the imprimatur of the United States Mission to the European Union. This edit and others offered a rare glimpse into the routine merging of the U.S. government with American corporations. When U.S. Representative Henry Waxman conducted an investigation into the Bush Administration’s efforts to undermine REACH, he unearthed dozens of pages of diplomatic cable traffic showing how the government had coordinated its efforts with those of industry. Talking points, lobbying junkets, statistics (many of them proven inaccurate) had been shared. Instead of considering these reforms on their merits, or revising its own failed regulations, our government demonstrated once again that it puts business interests ahead of the safety of its own — and the world’s — citizens.

The European Parliament finally voted to approve REACH on December 13, 2006. By February, the U.S. Department of Commerce, which had lobbied so vigorously against the proposed regulation, was hosting a seminar in Charlotte, North Carolina, to explain to companies doing business in Europe how to comply with the law intended to protect Europeans. It was the first of a series of sessions to be held with American businesses across the country. In the same month, representatives from the Pentagon, defense contractors, U.S. scientists, and California state officials met in Monterey to discuss the effects REACH would have on military hardware being used on U.S. bases in Europe. Several major American electronics and cosmetics companies are already reformulating their products to meet the new E.U. standards. And DuPont, Dow, and other large U.S. chemical manufacturers are busy preparing toxicity data to submit to the E.U. In many instances, smaller American chemical companies and most downstream manufacturers that utilize chemicals will have to purchase this data from the big corporations, which now stand to profit from the REACH strictures.

Many American states, tired of waiting for direction from Washington, are now looking to Brussels for ideas on environmental reform. California, Massachusetts, and New York have begun exploring the possibility of implementing elements of REACH in their state regulations; Maine and Washington have cited Europe’s precedent in their efforts to ban particular chemicals, such as those poly- brominated flame retardants found in children’s sleepwear. Elsewhere in the world, governments have worked to bring their own policies into line with REACH. The Chinese Ministry of Commerce had REACH translated into Mandarin within days of its passage. European consultants also traveled to China to show industry and government officials there what exporters will have to do to abide by the chemical regulations. The Europeans were willing to aid their competitors in China, with whom they have a significant trade deficit, because just about anything made in Chinese factories can end up in the hands of Europeans. To protect its population, Europe is working backward, toward the potential sources of future chemical contamination. European consultants also fanned out to Brazil, Mexico, South Africa, South Korea, Thailand, and other major players in the world economy. And in the upcoming year, Robert Donkers, who had long tried to forewarn American businesses of this tectonic shift in environmental influence, is expected to be transferred to India, where he will be advising that up-and-coming economic powerhouse.

The European Union is demanding that its industries take responsibility for the collateral health damages that its products may cause, and it is doing so with innovations that are leading the world. In the process, American consumers are being put in a position that would have been unimaginable as little as a decade ago. Shortly after the EPA was founded, the United States imposed domestic restrictions on some of the most dangerous pesticides and other chemicals, and U.S. companies responded by exporting millions of pounds of these toxins to Third World countries, where such regulations didn’t exist. The irony is that our nation’s steady retreat from environmental leadership means it may soon be-come a dumping ground for chemicals deemed too hazardous by more progressive countries. Meanwhile, Americans may also be the incidental beneficiaries of protective standards created by the government of a foreign country in which they have no say. In recent years the United States has opposed a multitude of environmental and human-rights initiatives that have gained international legitimacy without its participation. Indeed, this country is no longer where it likes to imagine itself to be — at the axis of influence around which the rest of the world revolves.


From: HealthDay
December 7, 2007


[Rachel’s introduction: Scientists have discovered the mechanism by which a chemical known as perchlorate can collect in breast milk and cause cognitive and motor deficits in newborns.]

By Carolyn Colwell, HealthDay Reporter

Scientists have discovered the mechanism by which a chemical known as perchlorate can collect in breast milk and cause cognitive and motor deficits in newborns.

Used since the 1940s to manufacture explosives and rocket fuel, the contaminant is still widely present in the water and food supply, experts say.

And high concentrations of perchlorate in breast milk can be passed to an infant and affect it’s ability to manufacture essential thyroid hormone, the new study suggests. Perchlorate can also lessen the amount of iodide available to a mother to pass on to her infant, and a baby needs iodide to produce thyroid hormones.

“The deficit of thyroid hormone is particularly delicate if it’s at the beginning of life because the central nervous system has not completely matured,” said study author Dr. Nancy Carrasco, a professor of molecular pharmacology at Albert Einstein College of Medicine, in New York City.

Thyroid hormones are “absolutely critical” for the development and maturation of the central nervous system, skeletal muscles and lungs, she explained.

In laboratory and rat research, Carrasco’s team found that perchlorate limited the amount of iodide transported to a mother’s mammary glands. The only source of iodide a baby typically has is mother’s milk, she explained.

Her team discovered that perchlorate accumulates in mother’s milk, but before this study, “we didn’t know it would be passed on as actively to the baby,” she said.

Carrasco and her colleagues at Einstein and at Johns Hopkins University reached this conclusion after experimental studies on how sodium iodide carries perchlorate to, and concentrates it in, mammary glands.

The next steps in this research will include animal studies looking at the effects of perchlorate exposure during pregnancy, she said.

The debate continues on how much perchlorate is a high and harmful concentration, Carrasco said. But scientists have long known that iodide deficiency contributes to lowered IQ.

The new finding is relevant to the Environmental Protection Agency’s standards for acceptable perchlorate levels, added R. Thomas Zoeller, a professor of biology at the University of Massachusetts-Amherst who has served on the EPA’s peer review panels for the assessment of perchlorate.

At the time the current safety standards were established, the EPA was not thinking about how perchlorate is concentrated in breast milk, he said.

Zoeller said the study’s discovery of how perchlorate is transported to breast milk is important to setting safety standards because perchlorate has a half-life of about eight hours and doesn’t accumulate in the body. But because of the new findings, “we no longer have to debate whether perchlorate is being concentrated in milk,” he added. “We have enough data to know that this is a very dangerous thing.”

Large studies need to be done to confirm the findings, Zoeller added.

It’s now “enormously important to find out if perchlorate in [breast] milk is affecting thyroid hormones in infants,” he said. Such a study would be difficult to conduct because it would involve drawing blood from 1- and 2-week old infants, Zoeller said.

Tyrone Hayes, a professor of integrative biology at the University of California at Berkeley, said the discovery of a mechanism by which perchlorate can be transmitted to nursing infants is important.

“I think probably the most obvious significance is that we have a very common contaminant in the environment that has a profound negative impact, and that the most profound impact is on humans that don’t have a choice at a critical development stage that can impact the rest of their lives,” he said.

The Environmental Protection Agency has more on perchlorate.

SOURCES: Nancy Carrasco, M.D., professor, molecular pharmacology, Albert Einstein College of Medicine, Yeshiva University, New York City; Tyrone Hayes, Ph.D., professor, integrative biology, University of California at Berkeley; R. Thomas Zoeller, Ph.D, professor, biology, University of Massachusetts, Amherst; December 3-7, 2007, Proceedings of the National Academy of Sciences online

Copyright 2007 ScoutNews, LLC.


From: Toronto Globe and Mail
December 6, 2007


[Rachel’s introduction: The international community may have as little as a decade to bring greenhouse gases under control or risk catastrophic global warming that places millions of people at risk, warns a group of the world’s leading climate scientists.]

Martin Mittelstaedt, Environment Reporter

The international community may have as little as a decade to bring greenhouse gases under control or risk catastrophic global warming that places millions of people at risk, warns a group of the world’s leading climate scientists.

In a declaration released today in Bali, Indonesia, where representatives from about 180 countries are attending a UN conference on climate change, the scientists say emissions need to peak and then start to decline within the next 10 to 15 years as a first step, and then be cut in half by 2050 from the level prevailing in 1990.

If releases aren’t curbed soon, “millions of people will be at risk from extreme events, such as heat waves, drought, floods and storms; our coasts and cities will be threatened by rising sea levels; and many ecosystems, plants and animal species will be in serious danger of extinction,” the scientists say in their declaration.

More than 200 leading researchers — many of the world’s pre-eminent climate scientists, including seven from Canada — endorsed the statement. Its release was timed to put heat on the negotiators at the Bali climate-change talks.

An ill wind blows

Government officials from the countries taking part in the Bali talks have been meeting this week, but starting next week, with the arrival of ministers and other elected officials, the pace of the talks is expected to quicken. The leaders are trying to lay the groundwork for plans to curb greenhouse-gas emissions after the Kyoto Protocol expires at the end of 2012.

The declaration was organized by scientists at the Climate Change Research Centre at the University of New South Wales, in Sydney, Australia.

Andrew Weaver, a climatologist from the University of Victoria who signed the declaration, said it was prompted because many scientists have become alarmed at the precariousness of the world’s weather system, and want to convey a sense of urgency to politicians about the need to do something to prevent dangerous changes.

Scientists are usually an “argumentative bunch” who “can’t even agree on the time of day,” yet more than 200 agreed to sign the statement, Dr. Weaver said in an e-mail. “I think it is a testament to the urgency of dealing with global warming.”

(The text of the declaration is posted at http://www.climate.un sw.edu.au/bali)

The declaration says emissions need to peak and start falling in the 10-to 15-year time frame to keep global temperatures from rising more than two degrees. That is a level beyond which many scientists fear widespread species extinctions would occur, along with harm to the massive Greenland ice sheet, whose melting would lead to extensive flooding in low-lying coastal areas.

Temperatures rose about 0.7 degrees Celsius during the 20th Century due to human activity.

To hold temperatures to a two-degree increase, greenhouse-gas concentrations will have to be stabilized at a level “well below” 450 parts per million, if all harmful gases are measured in terms of carbon dioxide, the declaration says. The current reading is about 430 parts per million.

Biologist John Smol of Queen’s University in Kingston and one of the signatories, said he thinks scientists have done a good job alerting the public to the threat posed by climate change, but he worries that political squabbling at the talks may delay action.

Copyright Copyright 2007 CTVglobemedia Publishing Inc.


From: Reuters
December 11, 2007


[Rachel’s introduction: The food web of Antarctica, and thus the survival of penguins and many other species, is bound up in the future of the sea ice, which has declined 40% in the last 26 years.]

By Sugita Katyal

NUSA DUA, Indonesia — Antarctica’s penguin population has slumped because of global warming as melting ice has destroyed nesting sites and reduced their sources of food, a WWF report (6 Mbyte PDF) said on Tuesday.

The Antarctic peninsula is warming five times faster than the average in the rest of the world, affecting four penguin species — the emperor penguin, the largest and the grandest in the world, the gentoo, chinstrap and adelie, it said.

“The Antarctic penguins already have a long march behind them,” Anna Reynolds, deputy director of WWF’s Global Climate Change Programme, said in a statement at the Bali climate talks.

“Now it seems these icons of the Antarctic will have to face an extremely tough battle to adapt to the unprecedented rate of climate change.”

The report, “Antarctic Penguins and Climate Change”, said sea ice covered 40 per cent less area than it did 26 years ago off the West Antarctic Peninsula, leading to a fall in stocks of krill, the main source of food for the chinstrap and gentoo penguins.

In the northwestern coast of the Antarctic peninsula, where warming has been fastest, populations of adelie penguins have dropped by 65 percent over the past 25 years, it said.

The number of chinstraps decreased by 30 to 66 percent in some colonies, as less food made it more difficult for the young to survive, while the emperor penguin has seen some of its colonies halve in size over the past half a century.

Warmer temperatures and stronger winds mean the penguins had to raise their chicks on increasingly thinner sea ice which tends to break off early while many eggs and chicks have been blown away before they were able to survive on their own.

Scientists have predicted that global temperatures could rise sharply this century, raising world sea levels and bringing more extreme weather.

A 2005 study showed that most glaciers on the Antarctic peninsular were in headlong retreat because of climate change — and the speed was rising. Scientists say that most of the rest of the ice on the giant continent seems to be stable.

“The food web of Antarctica, and thus the survival of penguins and many other species, is bound up in the future of the sea ice,” said James P. Leape, director general of WWF International.

“After such a long march to Bali, ministers must now commit to sharp reductions in carbon emissions for industrialized countries, to protect Antarctica and safeguard the health of the planet.”

(Editing by Alister Doyle)

Copyright Reuters2007


From: New Scientist (pg. 32)
December 8, 2007


[Rachel’s introduction: It has been a long slow revolution, but finally years of diligent research and investment by a group of true believers is beginning to pay off. Solar power has finally come of age.]

By Bennett Daviss

In theory, solving the world’s energy problems should be pretty straightforward. Locate a piece of sun-drenched land about half the size of Texas, find a way to capture just 20 per cent of the solar energy that falls there and bingo — problem solved. You have enough power to replace the world’s entire energy needs using the cleanest, most renewable resource there is.

Can it really be that easy? For years, supporters of solar power have heralded every new technical breakthrough as a revolution in the making. Yet time and again it has failed to materialise, largely because the technology was too expensive and inefficient and, unlike alternatives such as nuclear and wind power, no substantial subsidies were available to kick-start a mass transition to solar energy. This time things are different. A confluence of political will, economic pressure and technological advances suggests that we are on the brink of an era of solar power.

The prospect of relying on the sun for all our power demands — conservatively estimated at 15 terawatts in 2005 — is finally becoming realistic thanks to the rising price of fossil fuels, an almost universal acceptance of the damage they cause, plus mushrooming investment in the development of solar cells and steady advances in their efficiency. The tried-and-tested method of using the heat of the sun to generate electricity is already hitting the big time (see sidebar, “Hot Power”), but the really big breakthroughs are happening in photovoltaic (PV) cells.


Sidebar: Hot power

Exotic photovoltaic materials aren’t the only way to convert sunlight into electricity. Over the past few decades, techniques have been developed that use mirrors to concentrate the sun’s rays and convert the heat this generates into electricity on a commercial scale.

The most widely used so far is the solar trough concentrator system. Rows of parabolic mirrors track the sun, focusing its energy onto tubes filled with a fluid such as oil or water. The liquid is heated to around 400 deg. C and circulated to a conventional steam turbine to generate electricity. Solar trough systems convert roughly 20 per cent of the sun’s heat they capture into electricity, comparable with some commercial photovoltaic cells, but at a fraction of the cost.

In the late 1980s, nine parabolic-trough energy farms were built in the Nevada desert. Together covering just over 1 square kilometre, they produced 354 megawatts of electricity. Plans to expand the farm were abandoned in the early 1990s when the price of fossil fuels slumped, but they kept supplying power to the grid. Now, with energy prices on the rise, plans are being drawn up to revive the technology. In December 2005 the first trough system built in the US since 1988 was switched on in Seguaro, Arizona. It is capable of generating 1 megawatt of power.

An alternative to the trough system is the solar tower, pictured above, in which a field of flat mirrors track the sun and reflect its rays onto water pipes. The water boils, generating steam that drives a turbine. This approach achieves an efficiency of around 15 per cent. The first commercial solar tower, with a capacity of 11 megawatts, was completed in 2005 near Seville in Spain. Construction of a second tower, capable of generating 20 megawatts, began last year.

New solar tower designs replace the water with molten salts (for example, a mix of sodium nitrate and potassium nitrate) which can be heated to 600 deg. C. The heat can be used immediately to produce steam to drive a turbine, or stored and used overnight or when clouds block the sun.

Another method uses dish-shaped mirrors around 10 metres in diameter to focus solar energy onto a Stirling engine, which contains a gas that expands under heating and so drives a generator. At 24 per cent, its efficiency beats all other solar concentrator systems. In 2005, the California Public Utilities Commission, the state body responsible for regulating private power stations, gave the go-ahead for the world’s biggest solar dish concentrator farm to be built in the Mojave desert, north-east of Los Angeles. When completed in 2010, its 20,000- dish array will generate 500 megawatts.


Ever since the first photovoltaic (PV) cell was created by Bell Labs in 1954, the efficiency with which a cell can convert light into electricity has been the technology’s Achilles’ heel. The problem is rooted in the way PV cells work. At the heart of every PV cell is a semiconducting material, which when struck by a photon liberates an electron. This can be guided by a conductor into a circuit, leaving behind a “hole” which is filled by another electron from the other end of the circuit, creating an electric current (see Diagram).

Photons from the sun arrive at the semiconductor sporting many different energies, not all of which will liberate an electron. Each semiconducting material has a characteristic “band gap” — an energy value which photons must exceed if they are to dislodge the semiconductor’s electrons. If the photons are too weak they pass through the material, and if they are too energetic then only part of their energy is converted into electricity, the rest into heat. Some are just right, and the closer the photons are to matching the band gap, the greater the efficiency of the PV cell.

Bell Labs discovered that silicon, which is cheap and easy to produce, has one of the best band gaps for the spectrum of photon energies in sunlight. Even so, their first cell had an efficiency of only 6 per cent. For a long time improvements were piecemeal, inching up to the mid-teens at best, and at a cost only military and space exploration programmes could afford. The past decade has seen a sea change as inexpensive cells with an efficiency of 20 per cent have become a commercial reality, while in the lab efficiencies are leaping forward still further.

Last year, Allen Barnett and colleagues at the University of Delaware, Newark, set a new record with a design that achieved 42.8 per cent energy conversion efficiency. Barnett says 50 per cent efficiency on a commercial scale is now within reach. Such designs, married to modern manufacturing techniques, mean costs are falling fast too.

As a result, in parts of Japan, California and Italy, where the retail price of electricity is among the world’s highest, the cost of solar- generated electricity is now close to, and in some cases matches, that of electricity generated from natural gas and nuclear power, says Michael Rogol, a solar industry analyst with Photon Consulting, based in Aachen, Germany. For example, in the US the average price of conventionally generated electricity is around 10 cents per kilowatt- hour. The cost of solar-generated electricity has fallen to roughly double that. This has created a booming market for PV cells — now growing by around 35 per cent annually — and private investors are starting to take a serious interest. The value of stocks in companies whose business focuses primarily on solar power has grown from $40 billion in January 2006 to more than $140 billion today, making solar power the fastest-growing sector in the global marketplace.

George W. Bush has acknowledged this new dawn, setting aside $168 million of federal funds for the Solar America Initiative, a research programme that aims to make the cost of PV technology competitive with other energy technologies in the US by 2015. Rogol thinks Bush’s target is achievable. He says the cost of manufacturing PV equipment has fallen to the point where, in some places, PV-generated electricity could already be produced for less than conventional electricity. Manufacture PV cells at $1 per watt of generating capacity and the cost should be competitive everywhere.

Perhaps surprisingly, given its less than cloudless skies, one of the countries leading the solar revolution is Germany. In November 2003, amid rising oil and gas prices and growing concern over global warming, its parliament agreed a “feed-in tariff” programme, which guarantees a market for solar power. Anyone who produces electricity from solar power can sell it to the national grid for between $0.45 and $0.57 per kilowatt-hour, which is almost three times what consumers pay for their electricity, roughly $0.19 per kilowatt-hour. Germany’s power-generating companies are required by law to pay this premium, which is guaranteed until 2024. This guarantee has spurred enterprising individuals to invest in solar panels, confident of earning back the cost of their systems and possibly turning a profit. Today there are over 300,000 PV systems in Germany, mostly on the rooftops of homes and small businesses, and Germany is the world’s fastest-growing PV market. It has 55 per cent of the world’s installed base of PV panels and can generate around 3 gigawatts of electricity from solar energy, equivalent to between three and five conventional power stations.

Last year, following in Germany’s footsteps, Italy and Spain launched their own tariff programmes, while the California Solar Initiative earmarked $2.8 billion for cash incentives that will subsidise new PV installations to the tune of up to $2.50 per watt, with the aim of creating 3 gigawatts of capacity by 2016. By the end of 2008, 20 nations will have similar tariff programmes for solar power, Rogol predicts.

The hope is that by spurring demand, these subsidies will also stimulate PV research and manufacturing technology, driving down costs. This may help speed the development of existing PV technologies, but could also drive the industry down a blind alley, as silicon PVs may soon reach their theoretical efficiency limit of about 30 per cent. Yet according to Martin Green at the University of New South Wales, Australia, it should be possible to create cells from other materials with a 74 per cent efficiency limit. And while subsidies go some way to stimulating the market, most analysts agree that the cost of existing PV cells is too high for the technology to hit the mainstream.

That’s why researchers have been looking at alternative designs. One of the cheapest cells to manufacture is the thin-film cell, in which semiconductor compounds are sprayed onto a flexible substrate. Thin- film cells use as little as 1 per cent of the volume of materials that ordinary PV cells demand, and the band gap of the cells can be improved by adjusting the proportions of the ingredients that form the film. For example, cells that use a low-cost blend of copper, indium, a pinch of gallium, and selenium (CIGS), have already achieved an efficiency of around 19 per cent in lab tests. The material’s efficiency is so high relative to its cost that researchers have shifted their attention from boosting CIGS’s photon-collecting power to slashing the cost of producing the cells. This could enable the technology to deliver grid-competitive electricity within five years.

Grand designs

One innovation aimed at improving mainstream solar-cell design is the use of lenses to focus and amplify the amount of light hitting the PV material. Among the most successful designs to incorporate a concentrating lens is one created by Soliant Energy, a California start-up company staffed by scientists formerly at NASA’s Jet Propulsion Laboratory. Its PV module is a box holding rows of half- pipes, like gutters facing skywards. The trough of each half-pipe is lined with a strip of PV material, while the open side of the pipe is covered with an acrylic lens that concentrates sunlight by a factor of 500. This slashes the quantity of PV material required for a given power output, and thus the cost of the cell.

The company’s next generation of PV modules will couple concentrators with PV crystals made by Spectrolab, Boeing’s subsidiary which engineers PV materials for NASA space probes. With efficiencies of up to 40 per cent, these alternative materials are twice as good as current silicon PV cells, says Brad Hines, Soliant’s founder and chief technology officer. The downside is that they cost 100 times as much, but Soliant has found a way of using just a sliver of the amount used in spacecraft solar cells, keeping them affordable.

Barnett’s record-breaking cell also uses a concentrator, but it only needs to intensify the light by a factor of 20. The real breakthrough in Barnett’s design is to split the incoming light into separate beams, each containing a narrow range of wavelengths. These are each directed into materials optimised to convert those frequencies into electricity.

Light entering the cell first falls onto PV material that absorbs high-energy wavelengths of light up to 500 nanometres. Longer wavelengths slip through to a dichroic mirror — a material that reflects certain wavelengths while allowing others to pass through it. Here, light with wavelengths of between 500 and 900 nanometres is reflected onto one photovoltaic stack, while wavelengths longer than 900 nanometres pass through the mirror and fall onto another stack (see Diagram).

Barnett’s group is stepping back to let engineers at DuPont and other companies take on the task of producing a prototype. The US Defense Advanced Research Projects Agency has committed $33 million to the project, while cash from private investors could bring the total investment to as much as $100 million. Barnett says PV modules based on the new design could be up to 50 per cent efficient and should go on sale within five years, costing under $2 per watt.

There are yet more ambitious plans to build cheap, efficient PV cells. Several groups worldwide are now working with nanocrystals called quantum dots (see New Scientist, 27 May 2006, p 44) with the aim of developing low-cost PV cells with an efficiency of 42 per cent. The nanocrystal’s special properties mean one photon of light will release up to four electrons.

Martin Green, one of the leaders in the field, is designing quantum dots to match specific light spectra and so make them more energy efficient. He wants to address a specific problem with conventional solar cells: some of the energy supplied by an incoming photon is lost as heat. Green is designing “hot carrier” cells that should transfer more of the energy from the photon to the electron, producing a higher output voltage. “In principle, a hot carrier cell would have an efficiency quite close to the 74 per cent limit,” he says.

The challenge in creating a hot carrier cell is collecting the electrons quickly, before they move around the semiconducting material and lose their energy. That would mean creating a semiconductor shot through with nanowires or other collectors that would gather up electrons as soon as they are liberated from atoms — a requirement that could send manufacturing costs skyrocketing. “So far,” Green acknowledges, “we don’t know how to do that.”

Allen Heeger, at the University of California, Santa Barbara, is trying another approach. The co-inventor of plastics that can conduct electricity, Heeger has created a semiconducting plastic which allows incoming photons to liberate electrons, just as in silicon and other photovoltaic materials. In July, Heeger unveiled a two-layer polymer PV stack that reached 6.5 per cent efficiency, a record for plastic solar cells.

The promise of plastic PV cells, Heeger points out, is that they could be manufactured using a kind of printing process “similar to the way newspapers are printed”, because all the materials they are made of are soluble. “We have a goal of getting to 10 per cent efficiency and eventually well beyond that,” he says, but he’s not too bothered about efficiency. “The critical comparison is dollars per watt,” he says. “Even if our efficiency is lower than silicon, the cost per watt could still be better because this is such a low-cost manufacturing process.”

And perhaps that’s where the true promise of solar power lies, not in expensive high-efficiency cells, but in clever new designs that are dirt cheap to produce. It has been a long slow revolution, but finally years of diligent research and investment by a group of true believers is beginning to pay off. Solar power has finally come of age.

Energy and Fuels — Learn more about the looming energy crisis in our comprehensive special report.

Climate Change — Want to know more about global warming: the science, impacts and political debate? Visit our continually updated special report.

Bennett Daviss is a science writer in New Hampshire From issue 2633 of New Scientist magazine, 08 December 2007, page 32-37

Copyright Copyright Reed Business Information Ltd.


Rachel’s Democracy & Health News highlights the connections between issues that are often considered separately or not at all.

The natural world is deteriorating and human health is declining because those who make the important decisions aren’t the ones who bear the brunt. Our purpose is to connect the dots between human health, the destruction of nature, the decline of community, the rise of economic insecurity and inequalities, growing stress among workers and families, and the crippling legacies of patriarchy, intolerance, and racial injustice that allow us to be divided and therefore ruled by the few.

In a democracy, there are no more fundamental questions than, “Who gets to decide?” And, “How DO the few control the many, and what might be done about it?”

Rachel’s Democracy and Health News is published as often as necessary to provide readers with up-to-date coverage of the subject.

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