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.S. taxpayers are, in effect, subsidizing the Gulf of Mexico’s dead zone, an area of coastal waters where dissolvedoxygen concentrations fall to less than 2 parts per million every summer, according to a new paper published in ES&T (pp 5410–5418). These findings don’t bode well for the Gulf, as more and more acres of land are planted with corn to meet the growing U.S. demand for alternative fuels. Scientists studying nutrient inputs that feed the Gulf’s hypoxic zone have known that certain intensively farmed areas in the upper Midwest leak more nitrogen derived from fertilizers than others. Now, there’s a new twist. Farmers in areas with the highest rates of fertilizer runoff tend to receive the biggest payouts in federal crop subsidies, says Mary Booth, lead author of the paper and a former senior scientist with the Environmental Working Group. What’s more, they have fewer acres enrolled in conservation programs compared with other parts of the Mississippi River basin (MRB). Modeling the major sources of nitrate in the MRB, Booth and her colleagues found that fertilizer runoff is responsible for 59% of springtime nitrate loading to the Gulf, atmospheric deposition for 17%, animal waste for 13%, and municipal wastewater for 11%. These findings are consistent with earlier analyses but go a step further by homing in on the seasonal aspects of nitrogen flux rather than annual loading, says Richard Alexander, with the U.S. Geological Survey. “Spring flux is what matters most in predicting the formation of the [Gulf’s] hyp oxia zone,” he adds. Booth’s team added data from
This graph depicts the measured area of the Gulf of Mexico hypoxic zone—the world’s second largest—from 1985 to 2006. The area still far exceeds a federal action plan goal to reduce the zone to 5000 square kilometers (km 2 ) by 2015.
federal commodity support and conservation programs to their model. The output shows that a large proportion of the commodity subsidy payments from 1995 to 2002 went to the areas with the most runoff and the least amount of land enrolled in conservation programs. This paper “points out that a modest shift in federal agricultural spending priorities could help bring about large-scale increases in the type of conservation efforts necessary to restore ecological stability in the Gulf,” says Donald Boesch, president of the University of Maryland’s Center for Environmental Science. That finding correlates with what the U.S. EPA’s Science Advisory Board is recommending in a draft reassessment about the Gulf’s hypoxia. To accomplish this target, Booth adds, monies would have to be shifted from commodity to conservation programs under the Farm Bill set to expire in September.
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Legislation proposed in January to reauthorize the Farm Bill moves in that direction. Commodity spending would fall by nearly $4.5 billion, and conservation spending would rise by $7.8 billion over the next 10 years. A spokesperson for the U.S. Department of Agriculture (USDA) admits that the growing demand for ethanol is driving up the number of acres planted with corn and could cause land currently in conservation programs to be pulled back into production. Ethanol production capacity is being ramped up quickly. To fuel this expansion, USDA predicts, a record 90.5 million acres of corn will be planted this year in the U.S., 15% more than last year. “As long as we talk about more corn to serve as feedstock for ethanol, we’ve got some significant problems with nitrogen—no question about it,” says Gyles Randall, a soil scientist at the University of Minnesota. —KRIS CHRISTEN © 2007 American Chemical Society
Nancy R abal ais, Louisiana Universities Marine Consortium
Rewarding fertilizer pollution with crop subsidies
News Briefs
Roman Ashauer
The sequence in which organisms are exposed to chemicals could matter just as much as dose and length of exposure, according to new research published in ES&T (pp 5535–5541). Most risk assessments consider only one chemical at a time when looking at toxicity or other deleterious effects. But mixtures are important, especially in agriculture, where farmers may apply different pesticides throughout the growing season that run off into streams in pulses.
Tiny freshwater shrimp from this U.K. stream ended up in one of two scenarios (upper right): exposed sequentially to carbaryl and then chlorpyrifos, or vice versa.
Roman Ashauer and colleagues at the Central Science Laboratory and the University of York (U.K.) studied exposure to the pesticides carbaryl and chlorpyrifos. Both act on the nervous system by targeting the enzyme acetylcholinesterase (better known as AChE). Tiny freshwater shrimp, Gammarus pulex, eliminate the two pesticides in so-called depuration times that differ by only a few days. Ashauer collected G. pulex from a small stream, Bishop Wilton Beck, along with water samples for testing. The team then exposed the approximately 11-millimeter crustaceans to a pulse of one pesticide, followed by a 14-day period of depuration, and then a pulse of the
second. They selected this timing to ensure that the first pesticide was out of the shrimp’s systems. Two weeks after a hit of carbaryl (about 27 micrograms per liter [μg/L]), the tiny shrimp seemed to handle a pulse of chlorpyrifos (about 0.5 µg/L) fairly well, with mortality rates of 31% for carbaryl and 21% for chlorpyrifos. But when the order was reversed, G. pulex suffered more damage, with mortality rates of 12% for chlorpyrifos and 55% for carbaryl. Although the death rates for the chlorpyrifos pulses are relatively similar no matter the order (21% and 12%), “the mortalities from the two carbaryl pulses are significantly different from each other,” Ashauer says. The shrimp seemed not to have recovered completely from the first chlorpyrifos pulse, even though they should have according to depuration data from previous experiments. The authors hypothesize that the lingering damage from the chlorpyrifos primed the shrimp for even greater mortality with the second, carbaryl pulse, but exactly how remains to be determined. They suggest “damage recovery” times of about 15 days for carbaryl and 25 for chlorpyrifos. “If you just do any kind of sequence experiment, you might not find these effects,” says Ashauer. In this case, the timing had to be just right: had the time between pulses been much shorter (so the shrimp could not recover in time) or much longer (so the shrimp recovered completely from both), the effect of order may not have been evident. Ashauer notes that “one of the most interesting experiments in the future would be two compounds that have different target sites.”
Nano needs oversight
To ensure environmental responsibility in the rapidly expanding nanotechnology industry, the U.S. EPA needs to ramp up its oversight. That’s the bottom line of a report by the nonpartisan Woodrow Wilson International Center for Scholars. Offering guidelines for developing an appropriate nano-oversight system, the report, EPA and Nanotechnology: Oversight for the 21st Century, says that EPA needs to use existing regulatory frameworks such as those provided under the Toxic Substances Control Act and modify them when necessary to include nanotechnology. Other recommendations in the May report include better intra- and interagency dialogues, increased funding dedicated to the human and environmental health aspects of nanomaterials, and the establishment of congressional committees to weigh regulatory mechanisms.
Revisiting dredging
Dredging up contaminated sediments may be the U.S. EPA’s best bet to clean up some Superfund sites, but whether the process reduces the long-term risk to wildlife and human health remains to be proven, according to a report released in June by the National Research Council. The report, Sediment Dredging at Superfund Megasites: Assessing the Effectiveness, focuses on 26 dredging projects across the U.S. A dearth of long-term data prevents the evaluation of the real success of these cleanup efforts, but in many cases, short-term goals have remained elusive. The report recommends more pre- and postdredging data collection and adaptive management to improve results.
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U.S. EPA
Order matters in pesticide exposures
Environmentalt News Jim Lazorchak, an ecotoxicologist at the U.S. EPA in Cincinnati, calls the experiment “groundbreaking.” The team is “trying to explore modeling to predict realistic exposures,” he says, particularly for exposures to nonpoint sources of pesticides. Typical assessment methods don’t incorpo-
rate timing and order, which are critical in assessing real-world situations, where even more stressors occur, he emphasizes, from changes in water availability and climate to lack of food and habitat loss. “As far as assessing different exposure regimes, few people are getting involved” in such complex scenarios
he says, “but that’s the direction [eco]toxicology needs to go. “The order in which you are exposed is just as important as the concentration and duration you were exposed,” Lazorchak says. The question now becomes “Why is the order important?” —NAOMI LUBICK
EPA releases list of potential endocrine disrupters In mid-June, the U.S. EPA released its much-anticipated draft list of compounds to screen for endocrine disruption. The long-overdue list, which should have been completed in 1999, includes known and suspected endocrine disrupters, and all substances are pesticides selected because of their potential for human exposure and their high production volumes. The compounds were not chosen because they are suspected endocrine disrupters, EPA emphasized. The draft list contains 73 substances: 69 pesticides and 4 inerts used in pesticide formulations. More than half of the compounds have known effects on the endocrine system or have proven antiandrogenic or estrogenic activity. Theo Colborn, a longtime endocrine disruption researcher and activist, calls the list “unbiased” because to her it appears that EPA didn’t favor business interests. But she adds that “the whole thing is a waste.” Colborn and many other scientists, activists, and business representatives met with and advised EPA as it developed a process to select compounds and create a testing protocol for endocrine disrupters. Many say they are disappointed in the choices EPA has made on assays and in the compounds that didn’t make the list. “Why are they including things that are obviously endocrine disrupters? Why put them through a screening and waste precious resources and time on something we already know is an endocrine disrupter?” asks Sarah Janssen of the
environmental group Natural Resources Defense Council (NRDC). Mark Maier, a toxicologist and health science policy manager with the pesticide industry trade association CropLife America, agrees. “There are really no surprises on the list,” he says, but “the screening tests are redundant” and “unnecessary” because the pesticide manufacturers already test their products more comprehensively than any other industry does. “In some cases, endocrine activity may not be directly attributable to the parent compound” but instead to its metabolites, Maier says, “so it could be missed by screening.” And no unknowns appear on the list. “The program evolved through a political process, not a scientific process,” he says. Even so, EPA officials will not call these substances endocrine disrupters until they have gone through the agency’s entire testing battery, a series of assays that some critics say are not sensitive enough to detect low-dose exposures. Janssen notes that people are exposed to “six or seven phthalates on a daily basis that act together. . . . It doesn’t make sense for EPA not to look at them as a mixture.” But mixtures testing is not yet in the mix, and EPA continues to delay work on the simpler singlecompound tests. So far, only two tests have been validated—uterotrophic and Hershberger assays— both of which are considered old standards by scientific measures. EPA’s Linda Phillips, who leads the testing program, says that if vali-
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dation and peer review go well, she hopes to see all the screening tests online by 2008. But the agency’s past delays have bred skepticism among all of those who have advised the agency. After “all this effort, all this time spent in over 10 years, there’s been amazingly little progress made, and yet the agency expects to have all these tests wrapped up, validated, and ready for use by companies by 2008,” says James Stevens, a former Syngenta scientist and professor at Wake Forest University who participated in several of the EPA advisory committees. Stevens says he believes that the tests being required by EPA are more than sensitive enough to determine whether a substance is an endocrine disrupter. NRDC’s Janssen says EPA should move on to other compounds immediately. Drinkingwater contaminants that aren’t on the draft list—nonylphenols and octaphenols in particular—have “widespread potential for human exposure and are already having wildlife effects,” she points out. But the second list of candidate screening compounds remains far off in the future, after the agency establishes its testing protocols. And even if EPA approves its tests by the end of the year, Colborn argues, the procedure may never be adequate: “The endocrine system is so complex that you can’t say, ‘This is a safe product,’ ” perhaps no matter how many of the current tests it passes. —NAOMI LUBICK
Faced with a cumulative body of evidence that links serious health problems with prenatal and early infancy exposures to various chemicals, an international assembly of scientists, doctors, and researchers says it’s time to take action.
Fetal exposure of mice to nutrient supplements (genistein or various combinations of vitamin B12 , folic acid, choline, and betaine) contributed to epigenetically induced changes. Image from Dolinoy et al. (Environ. Health Perspect. 2006, 114, 567–572).
The public proclamation came at the end of a conference held last May in the Faroe Islands. The multidisciplinary support of the “Faroes Statement” from nearly 200 people adds considerable weight to several decades of diverse science on the effect of pollutants at these early stages of development. The statement refers to the growing number of substances that affect developing embryos and infants, including the pesticides DDT, atrazine, methoxychlor, and vinclozolin. Other suspects include the plastics and epoxy resin ingredient bisphenol A, plasticizing agents called phthalates, and the drug diethylstilbestrol, once used to prevent miscarriages and other pregnancy problems, as well as mercury, lead, arsenic, organotins, PCBs, carbon monoxide, fine particulates, tobacco smoke, and alcohol. “Until now, it’s been difficult to know if there’s a consensus on the issue,” says Bruce Lanphear, a pediatrics professor at Cincinnati Children’s Hospital Medical Center who attended the conference. Public-health officials are con-
cerned about early exposures, even at very low concentrations, to certain chemicals that might be linked to major health problems later in life. The statement also shines a light on the relatively new field of epigenetics, which finds that numerous heritable changes occur through alterations of a gene’s function and not just changes in its structure. Research in epigenetics by Michael Skinner, director of the Center for Reproductive Biology at Washington State University, and his colleagues has found that disorders—for example, breast tumors, kidney disease, and immune abnormalities—caused by prenatal exposure in rats to the fungicide vinclozolin can extend through at least four generations even without direct exposure to the fungicide by subsequent generations (Endocrinology 2006, 147, 5515–5523; 5524–5541). Skinner and his team have also found in a published study (Proc. Natl. Acad. Sci. U.S.A. 2007, 104, 5942–5946) that females at least three generations removed from the brief initial exposure preferred males who were not exposed, suggesting implications for mate selection and evolution. The declaration calls for governments to make changes in policies and regulations to help prevent exposures; improve and expand baseline testing to assess human exposures and environmental occurrences; and conduct more research on topics such as disease processes, exposure timing, effects of mixtures, and nonchemical influences, such as socioeconomic factors. The statement was developed by a 28-person international committee before the conference, but it wasn’t officially signed by any group. Still, the sponsors of the meeting included the World Health Organization (WHO), the European Environment Agency, the U.S. Centers for Disease Control and Preven-
News Briefs Congress and carbon sequestration
The U.S. Congress should mandate a standard for all new coal-fired power plants that requires them to control emissions to a level that can be obtained through a carbon capture and sequestration (CCS) system, asserts the nonprofit research group Center for American Progress (CAP). Such a move would demonstrate U.S. leadership and create a technological and regulatory foundation that countries such as China and India could emulate, CAP writes in a new paper, Global Warming and the Future of Coal. The great challenge for CCS is making sure its widespread deployment happens soon. The group recommends policies such as allowing the construction of some power plants that don’t meet CCS emissions levels and initiating a greenhousegas cap-and-trade program.
Low-cost greenhousegas controls
Six advanced energy technologies have the potential to control greenhouse-gas emissions at low cost if they are deployed on a large scale across the globe, according to a consortium of U.S. government scientists and their international collaborators. Global Energy Technology Strategy, a report released in May by Battelle, the U.S. Department of Energy’s Pacific Northwest National Laboratory, and the University of Maryland, marks the first effort to blend all aspects of climate change into a global systems model that integrates energy use and economics. The technologies analyzed are CO2 capture and storage; biotechnology; hydrogen systems; nuclear energy; wind and solar energy; and end-use energy technologies that can be used in buildings, transportation, and industry. To view the report, go to www.pnl.gov/gtsp.
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jupiterimages
Consensus reached on prenatal exposures
Environmentalt News tion, and the U.S. National Institutes of Health. WHO already has begun to circulate the declaration among organizations it works with. The architects of the U.S. National Children’s Study (NCS) say they will consider the statement. NCS, scheduled to begin in mid2008, is designed to provide longterm and case-control studies of 100,000 children from preconception to age 21 for a wide range of health issues. Sarah Keim, NCS coordinator, says, “We will always up-
date our plans to reflect the latest thinking and hope to answer a lot of the questions that were raised.” Yet, incorporating the information addressed by the proclamation into policies and regulations is likely to be a slow, incremental process. In Europe, new chemical regulations known as REACH (the Registration, Evaluation, and Authorisation of Chemicals), which went into effect on June 1, address prenatal and early infancy exposures in only a limited way, says
Philippe Grandjean, co-chair of the conference, who holds positions at the University of Southern Denmark and the Harvard School of Public Health. He says it’s possible that the European Parliament may consider this issue as it works through its reauthorization of pesticides. The final statement is expected to be posted on the website of the journal Basic & Clinical Pharmacology & Toxicology later this year, Grandjean says. —ROBERT WEINHOLD
For decades, paper mills, municipal waste incinerators, and petrochemical industries lining the banks of the Houston Ship Channel (HSC) have filled the waters with 2,3,7,8-tetrachlorodibenzop-dioxin and its equivalents. The sediments lying underneath still bear that toxic legacy. A new study published in ES&T (pp 5291–5298) suggests that soil erosion, hurricanes, tides, shipping, and dredging may be churning up contaminants, transporting them to different parts of the channel, and reintroducing them into the aquatic environment. The findings may help reveal why mysteriously high dioxin levels are in fish and shellfish in the channel despite tight regulations on emissions. The HSC is a 52-mile-long, very narrow channel and is one of the busiest ports in the U.S. It receives freshwater from the San Jacinto and Trinity rivers and connects to the Gulf of Mexico via Galveston Bay. High concentrations of dioxins have been found in blue crab and catfish in the HSC since Texas first started testing for the chemicals in the early 1990s. In other places in the state, tissue levels of dioxins plummeted within 1–2 years of reductions in emissions, but in the HSC, levels have remained almost constant, even after a decade of tightened regulations on industries and years of
Ke vin Ye ager
Unleashing a dioxin legacy
The waters and sediments of the HSC remain contaminated with dioxins despite a decade of tighter regulations.
cleaning up. This suggests that “something different was happening” there, says Larry Koenig, manager of the Texas Commission on Environmental Quality’s HSC Total Maximum Daily Load project, which is determining acceptable amounts of daily dioxin input into the channel. “We’re finding alarming amounts of it, and what we want to know is: is this dioxin derived from continuing inputs, or is it legacy dioxin,” says Kevin Yeager of the University of Southern Mississippi, who teamed up with Hanadi Rifai of the University of Houston and other colleagues for the current study. Yeager and his team collected 55 sediment cores from the upper part of the channel. Most of the cores were so heavily mixed that they were unsuitable for analysis. The team settled on eight sediment cores that showed the least
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amount of mixing and analyzed them for the rate of sedimentation and the rate of deposition of 17 of the most toxic dioxins and other airborne pollutants. They also tested for dioxin content and changes in dioxin concentrations within each core. They compared these findings with a background atmospheric dioxin deposition rate obtained from one sediment core from a wetland farther northwest. Although most of the sites had recently deposited dioxins, the observed rate of deposition could not be explained by atmospheric processes alone. “Some industries do continue to produce and emit dioxin, although much reduced from pre-1990s,” says Koenig. “At this time, we do not have any specific indication that a specific type of industry or specific facility is currently emitting enough dioxin to exceed water quality standards.” The traditional view on dioxins is that they attach to organic matter in sediments and get buried over time. But Yeager and colleagues’ study shows why things are different in the HSC: dioxins there do not bind to the organic matter in the sediments as tightly as expected. Taken together, these findings suggest that the HSC sediments are unable to safely store historic dioxins and are reintroducing them to the aquatic environment. Yeager’s team is currently studying the impact of dredging on dioxin distribution in the sediments. —RHITU CHATTERJEE
News Briefs
He ath R auschenberger
Alligator populations have recovered slowly since the federal government declared the species endangered in 1967, but a new study published in ES&T (pp 5559–5563) illustrates that they are not completely out of danger. The study confirms previous suspicions that organochlorine pesticides (OCPs) in reconstructed wetlands in Florida affect the survival of gator eggs and demonstrates, for the first time, a pathway by which these historic chemicals might reach the eggs. The findings raise questions about the future of such restored ecosystems.
Alligators in Lake Apopka are still battling the effects of residual pesticides from years of agriculture in the area.
In Florida, large swaths of wetlands were converted into farmlands beginning in the 1900s. But agricultural runoff soon began to boost nutrient levels in adjacent lakes, thus affecting wildlife and the overall health of the ecosystems. The state bought the lands from the farmers in the 1990s to reduce nutrient input into the lakes and to restore wildlife, says Mike Coveney, an environmental scientist at St. Johns River Water Management District, one of five such districts in Florida. But residual pesticides in the farms have remained a problem for wildlife, including the ecosystem’s top predator—the alligator. Scientists began to notice the effect of OCPs such as chlordane, toxaphene, and dieldrin on the reproductive systems of alligators in Florida lakes in the early 1990s.
Louis Guillette of the University of Florida recorded that pesticides in the marshes were causing the male gators to have smaller penises and the females to have abnormal egg development. About the same time, Allan Woodward of the Florida Fish and Wildlife Conservation Commission noticed fewer eggs hatching in lakes that had high levels of pesticides. But that amounted to nothing more than “coincidental evidence” for a potential link between pesticides and survival of the eggs, says Woodward. The alligator population in Lake Apopka has revived in the past two decades, and the hatching rate has bounced back to about 50% from less than 10% in the 1980s, he says. But “we still don’t see the hatching rate that we’d like to see.” To further examine the possible connection between pesticides and egg survival, Heath Rauschenberger of the University of Florida and colleagues painstakingly documented the levels of OCPs in alligator eggs from four highly contaminated lakes (Lake Apopka, Lake Griffin, and two lakes in the Emeralda Marsh Conservation Area) and two relatively uncontaminated ones (Orange Lake and Lake Lachloosa). They found a strong correlation between a lower hatching rate (about 40%) in the clutches and high pesticide concentrations. When the researchers bred alligators in captivity and fed them environmentally relevant concentrations of a mixture of four OCPs, the alligator eggs ended up with OCP levels similar to those of pesticide-exposed eggs in the wild and with similar hatching success. This suggests that alligators in the wild are consuming pesticides through their diet, ultimately leading to deposition of the toxic chemicals in their eggs. The study gives the first proof of “causation” for the low viability of alligator eggs in pesticide-contam-
Sowing carbon credits
Forests and farmlands may offer the first, best front for reducing U.S. greenhouse-gas emissions, according to a new mitigation guide published by Duke University and the advocacy group Environmental Defense. Designed as a how-to manual, it lays out how to turn forestry and farming activities into verifiable, tradable credits in future carbon markets. Highlighted projects remove CO2 from the atmosphere by sequestering it in soils (for example, no-till farming) or biomass (planting new forests and grasslands). The guide also looks at reducing greenhousegas emissions, such as methane from livestock and rice production. The suggested approaches ensure that offsets are real and that verification costs won’t sink a project, said economist Zach Willey of Environmental Defense when the guide was released in May. Go to www.env.duke. edu/institute/ghgoffsetsguide.
Cities for sustainability
EU ministers signed a charter in May that outlines for the first time the ideal European city for the 21st century. The Leipzig Charter on Sustainable European Cities will focus on helping cities tackle problems of social exclusion, structural change, aging, climate change, and mobility. The signatories agreed on common strategies for urban-development policy, including assisting “deprived” neighborhoods. Funding is also an issue. So far, €19.5 billion ($26.2 billion) of EU funding has been earmarked for cities. But the Leipzig Charter makes it clear that member states will need to do more on their own to contend with demographic change, global warming, and economic structural change. It recommends that governments make more use of public–private partnerships to enhance investments in city infrastructure.
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Florida gators battle pesticides
Environmentalt News inated lakes, says Rauschenberger, lead author of the new ES&T research. And “it indicates that if this is happening to alligators, it’s happening to turtles. If it’s happening to turtles, it’s happening to frogs and birds,” adds coauthor Timothy Gross of the University of Florida, who is also finding similar effects in fish and water birds.
But “to use a cliché, it is always more complex than it initially appears,” says Rauschenberger. OCPs seem to be only part of the story. “Other factors, such as nutrition and algal toxins, may also be direct or indirect contributors” to the problem, Woodward says. The findings have important implications for restoring wet-
Ontario, Canada’s most populous province, rushed stringent new testing regulations into place this month after finding high levels of lead in its drinking water. But Ontario’s lead problem could well be the tip of the iceberg for Canada, say some experts. Canada lacks national rules for monitoring tap water and doesn’t survey blood-lead levels in children or pregnant women, the most vulnerable populations. To make matters worse, some Canadian regions have naturally corrosive water and use water treatments that reduce disinfection byproducts. These treatments are likely to lower pH and enhance corrosivity. “Across the country, there has been little in the way of water sampling. So we don’t know how big the water problem could be,” says engineer Ian Douglas with the City of Ottawa Drinking Water Services. Insufficient information also applies to childrens’ blood-lead levels. “There is not adequate surveillance data,” says Bruce Lanphear, director of the Cincinnati Children’s Environmental Health Center. Children are most vulnerable to low-level lead exposure, which harms brain and neurological development at all concentrations. Pediatrician Michael Shannon at Children’s Hospital in Boston notes that water is a primary source of background exposure. A 1993 Canadian study found that lead in household water was the pri mary residential source in Saint
PHOTOS.COM
Lead levels high in Canadian tap water
Elevated levels of lead have been found in drinking water from 16 Ontario municipalities, including Toronto.
John, New Brunswick (Balram, C. A Study of Blood Lead Levels in Children Living in Saint John, New Brunswick; New Brunswick Health and Community Services: Saint John, New Brunswick, 1993). Ontario’s new regulations require schools and day-care centers to test for lead annually. Those built before 1990 have to flush their water systems daily. Further proposals for municipalities include sampling taps for lead every 6 months and optimizing corrosion control. Water companies that are out of compliance must monitor a smaller number of taps every 2 weeks. Ontario utilities are reeling from the changes. “This marks a
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lands, says Mike Hooper at Texas Tech University. “They’re trying to restore a lost ecosystem, and that’s not easy when contaminants are involved,” he says. “This work demonstrates that one good model to monitor levels of exposure over time might be alligator eggs,” says Coveney. —RHITU CHATTERJEE
huge shift. I doubt whether any Ontario utility could achieve this as it stands,” says one Canadian industry insider. Almost 100 comments have been filed about the proposal from a range of groups, says Sharon Bailey of the Ontario Ministry of the Environment (MOE). The agency plans to update the proposal before it is finalized later this year, she says. The proposal comes just weeks after provincially ordered testing in 36 municipalities found that almost half of the communities, including Toronto, had some lead levels that exceeded Health Canada’s standard of 10 parts per billion even after the taps were flushed for 5 minutes. Excessive lead levels found in London, Ontario, this spring prompted these tests. John Steele, a spokesman for MOE, says that a 5-minute flush is realistic given the way people behave in the morning. But community activists say that sampling needs to be applied to the worst-case scenarios. “To be health-protective, we should be concerned about the worst case, the sleepy woman coming downstairs and making formula for her infant,” says Barbara McElgunn, health policy officer for the Learning Disabilities Association of Canada, a nongovernmental organization. Some monitoring is in the works, however. The Canadian Health Measures Survey launched in March will measure blood-lead levels in 5000 Canadians, including children ages 6–19. Survey results are expected in 2010. —REBECCA RENNER
