(Beyond Pesticides, February 10, 2011) Despite the numerous scientific data on the devastating health and environmental consequences of endosulfan —a pesticide so toxic that is banned in over 60 countries including the U.S., officials in India say that a ban on the widely used chemical would put the country’s food security at risk and harm the welfare of farmers. However, thousands of villagers in Kerala, India, who have become disabled due to the use of the pesticide, pushed for a state ban in 2004 and have since joined the global movement to ban endosulfan. Doctors say that over 550 deaths and health problems in over 6,000 people in the region are related to the aerial spraying of the pesticide over cashew farms between 1979 and 2000. “Six thousand patients living with disabilities is not enough scientific evidence to enforce a national ban?,” asked B.C. Kumar, to the Washington Post. Kumar’s father, a cashew farm laborer, died of cancer. The endosulfan industry in India is estmiated to be worth over $100 million, making it the world’s largest producer, exporter and user of the product. The three companies that produce the product in India, including one that is partially government-owned, claim that […]

(Beyond Pesticides, December 16, 2010)The Center for Biological Diversity notified the U.S. Fish and Wildlife Service (USFWS) and U.S. Environmental Protection Agency (EPA) December 15 of its intent to sue the agencies for failing to study and act on threats posed by more than 60 pesticides to the threatened California red-legged frog. A 2006 legal settlement secured by the Center required the EPA to assess the impacts of pesticides on the frog, then consult with the U.S. Fish and Wildlife Service (USFWS) under the Endangered Species Act to address those impacts, by 2009. The completed assessments were submitted to the Wildlife Service between March 2007 and October 2009. Although EPA determined that 64 registered pesticides are likely to harm the frogs, the Service has not completed any consultations or adopted protective measures. “The EPA acknowledges that scores of pesticides may be dangerous to California’s rare red-legged frogs, but nothing’s been done about it,” said Jeff Miller, a conservation advocate with the Center. “This three-year delay violates the Endangered Species Act and jeopardizes the future of the largest native frog in California.” Historically abundant throughout California, red-legged frogs have declined in numbers over 90 percent and have disappeared from 70 percent […]

(Beyond Pesticides, December 8, 2010) A new study finds that oral contraceptives are not the main culprit in estrogenic pollution of U.S. rivers and drinking water. Instead, the contribution of contraceptives is quite small compared to other human, industrial and agricultural sources, including pesticides. Recent observed feminization of aquatic animals has raised concerns about estrogenic compounds in water supplies and the potential for these chemicals to reach drinking water. Public perception frequently attributes this feminization to oral contraceptives (OCs) in wastewater and raises concerns that exposure to OCs in drinking water may contribute to the recent rise in human reproductive problems. Studies have suggested that long-term exposure to low levels of estrogens in water may adversely affect human health. This new information eases concerns that contraceptives are a major factor contributing to feminized fish and frogs. This study, “Are Oral Contraceptives a Significant Contributor to the Estrogenicity of Drinking Water?” reviews the literature regarding various sources of estrogens, in surface, source and drinking water, to determine whether OCs were the source of estrogen in surface waters, with an emphasis on the active molecule that comes from OCs. The authors find that industrial and agricultural sources not only discharge estrogens, but […]

(Beyond Pesticides, October 15, 2010) Reversing previous rulings that claimed that the toxic pesticide endosulfan was “safe,” the Australian Pesticides and Veterinary Medicines Authority (APVMA) announced its decision Tuesday to finally cancel the registration of the highly hazardous chemical. Recent assessments by the Australian government’s Department of Sustainability, Environment, Water, Population and Communities (DSEWPC) concluded that the prolonged use of endosulfan is likely to lead to adverse environmental effects via spray drift and run-off, and that these long-term risks could not be mitigated merely through use restrictions or label changes. Australia joins over 60 countries, including to the U.S. to have banned endosulfan. Endosulfan is an organochlorine insecticide that was first registered for use in the U.S. in the 1950s. It is an endocrine disruptor and exposure in male children may delay sexual maturity and interfere with sex hormone synthesis. Endosulfan also decreases semen quality, sperm count, spermatogonial cells, and sperm morphology, and contributes to other defects in male sex hormones. It is volatile, persistent, and has a high potential to bio-accumulate in aquatic and terrestrial organisms. Two-headed bass, for example, were found in the Noosa River resulting from surrounding pesticide drift from neighboring farms in Queensland, Australia. The pesticides, […]

(Beyond Pesticides, August 26, 2010) Researchers from Indiana University have detected organochlorine pesticides and flame retardants in blood samples taken from bald eagle nestlings in the Great Lakes region. After DDT was banned, many scientists expected the bald eagle population to recover more quickly, so this study provides some evidence to explain their lackluster rebound. The researchers found not only organochlorines and PCBs (polychlorinated biphenyls), but several flame retardants commonly used in foam padding, such as pentabromoethylbenzene (PBEB), hexabromocyclododecanes (HBCDs) and Dechlorane Plus (DP). The paper, published in the August issue of the scientific journal Chemosphere was authored by Marta Venier of Indiana University. Ms. Venier and her colleagues collected blood samples by climbing trees to access the nests, carrying the nestlings carefully to the ground, and drawing a small blood sample before returning them to their nests. The statistically significant relationship between the total PBDE concentrations and total PCB concentrations suggest that these young eagles are ingesting pesticides and flame retardants through their food. Even low levels of these chemicals could be advsersely affecting the eagle population because as co-author of the study, Ronald Hites of Indiana University says, “Eagles are very vulnerable to chlorinated compounds.” Chlorinated materials are […]

(Beyond Pesticides, June 25, 2010) Two new studies published in the journal Environmental Science and Technology confirm that the majority of toxic contamination threatening national parks originates from agricultural pesticides and industrial operations. In one study an international group of scientists conducted research from 2003-2005 and detected elevated concentrations of various dangerous pesticides in all eight of the national parks and preserves. The other study collected samples of air, water, snow, sediment, lichens, conifer needles, and fish at remote alpine, subarctic, and arctic sites. Researchers found that these samples contained four current-use pesticides including dacthal (DCPA), chlorpyrifos, endosulfans, and y-hexachlorocyclohexane (HGH) as well as four historic-use pesticides including dieldrin, a-HCH, chlordanes, and hexachlorobenzene (HCB). Pesticide concentrations in snow are highest in Sequoia, Kings Canyon, Rocky Mountain and Glacier National Parks. Concentrations in vegetation are mostly dominated by endosulfan and dacthal, and are highest in Yosemite, Kings Canyon, Glacier, and Great Sand Dunes National Park and Preserve. Fish samples also show elevated concentrations of dieldrin and DDT (one of the first pesticides to be banned in 1972 because of Rachel Carson’s Silent Spring). Cold temperatures in alpine or arctic ecosystems tend to concentrate pesticides, which can also bioaccumulate in the local […]

(Beyond Pesticides, June 10, 2010) After years of pressure from environmental and international groups concerned about the chemical’s health effects, the U.S. Environmental Protection Agencey (EPA) announced that it is taking action to end all uses of the insecticide endosulfan in the United States. EPA has decided that new data presented to the agency in response to its 2002 reregistration eligibility decision (RED) have shown that risks faced by workers are greater than previously known. EPA also has found that there are risks above the agency’s level of concern to aquatic and terrestrial wildlife, as well as to birds and mammals that consume aquatic prey which have ingested endosulfan. Farmworkers can be exposed to endosulfan through inhalation and contact with the skin. An organochlorine insecticide first registered in the 1950s, endosulfan is used on a variety of vegetables, fruits, cotton, and on ornatmental shrubs, trees and vines. It poses unacceptable neurological and reproductive risks to farmworkers and wildlife and can persist in the environment. According to the EPA, crops with the highest use in 2006 — 2008 included tomato, cucurbit, potato, apple, and cotton. The use of endosulfan decreased overall from 2001 to 2008. A restricted use pesticide, endosulfan may […]

(Beyond Pesticides, March 30, 2010) Searching for clues to the mysterious disappearance of bees, known as “colony collapse disorder”(CCD), Penn State University researchers have identified widespread pesticide contamination of beehives. The study, “High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health,” was published March 19, 2010 in the scientific journal Public Library of Science (PLOS). The study finds 121 different types of pesticides within 887 wax, pollen, bee and hive samples from 23 states. The top 10 most frequently detected pesticides are fluvalinate, coumaphos, chlorpyrifos, chlorothalonil, amitraz, pendamethalin, endosulfan, fenpropathrin, esfenvalerate and atrazine. Miticides are the most common contaminant in the wax and bees, and fungicides are the most common contaminant of pollen. For the full results of the study, including several tables of wax, pollen and bee sample data, download the study from the PLOS website. “The pollen is not in good shape,” Chris Mullin, PhD, lead author of the study, told Discovery News. The authors state that the 98 pesticides and metabolites detected in mixtures up to 214 parts per million (ppm) in bee pollen alone represents a remarkably high level for toxicants in the brood and adult food of this primary […]

(Beyond Pesticides, January 14, 2010) Stating that current water-quality criteria does not reflect the latest scientific knowledge, The Center for Biological Diversity petitioned the U.S. Environmental Protection Agency (EPA) to establish new water-quality criteria for numerous endocrine-disrupting chemicals (EDC) under the Clean Water Act. If adopted, it will be a big step in regulating and eliminating persistent and widespread chemicals that damage reproductive functions in wildlife and humans. The Center for Biological Diversity formally requested that the EPA publish water quality criteria and information taking into account overwhelming science about the effects of EDC pollution on January 11. It says that under the Clean Water Act, EPA has a duty to periodically update water quality criteria to reflect the latest scientific knowledge. The petition presents scientific information on endocrine disrupting chemical pollution found in our waters and requests that the EPA promptly update water quality criteria reflecting this scientific information. Last month, legislation was introduced into Congress to explore linkages between hormone disrupting chemicals in the environment and everyday products and the dramatic increase of autism, hyperactivity, diabetes, obesity, breast cancer, prostate cancer and other hormone related disorders. After the identification of endocrine disruptors, the bill, The Endocrine Disruption Prevention […]

(Beyond Pesticides, January 13, 2010)The Coalition Against Bayer Dangers, based in Germany, is urging the multinational company Bayer to withdraw its most dangerous pesticides from the world market. The network specially is calling on Bayer to end sales of all products that contain active ingredients in the highest acute toxicity Class 1 of the World Health Organization (WHO) classification of pesticides. Bayer is the world market leader in sales of pesticides, many of which account for pollution and poisonings all over the world. The company acknowledges that “crop protection products may not always be used correctly under certain circumstances in some Third World countries.” Already in its 1995 Annual Report Bayer promised to “replace products with the Classification 1 of the World Health Organization with products of lower toxicity.” Public health advocates say that safe use of Class 1 (highest acute toxicity) pesticides is not possible, especially in countries where, because of poverty, illiteracy and other social conditions, as well as tropical climatic conditions, do not permit the wearing of protective gear. WHO estimates the number of people poisoned annually at three to 25 million. At least 40,000 people are killed accidentally by pesticides every year. The estimated number of […]

(Beyond Pesticides, December 21, 2009) Earlier this month, Congressman Jim Moran of Northern Virginia and Senator John Kerry of Massachusetts introduced legislation to explore linkages between hormone disrupting chemicals in the environment and everyday products and the dramatic increase of autism, hyperactivity, diabetes, obesity, breast cancer, prostate cancer and other hormone related disorders. After the identification of endocrine disruptors, the legislation requires federal agencies with regulatory authority to report to Congress on the action it plans to take. For years, scientists have noted strange anomalies in fish and wildlife in locations where endocrine disrupting chemicals (EDCs) are found. A recent study found that an astounding 100 percent of small mouth bass in certain sites of the Potomac River basin have exhibited both male and female organs, a characteristic linked to EDCs. According to a 2009 study by the U.S. Geologic Survey, the occurrence of “intersex” fish is now found to be nationwide. “These fish are the proverbial ”˜canaries in the coal mine,’ a symptom of a larger sickness in our environment. The implications for humans are real and deeply troubling,” said U.S. Representative Moran, who worked with experts for roughly a year to craft the legislation. “We need facts driven […]

(Beyond Pesticides, December 8, 2009) Following a recent recommendation by the international Persistent Organic Pollutants Review Committee to take “global action” to address health and environmental impacts, a broad coalition of 42 environmental, health, labor, and farming groups sent a letter to EPA Administrator Lisa Jackson urging EPA to finally take action to ban the antiquated insecticide. Acute poisoning from endosulfan can cause headaches, nausea, vomiting, convulsions, and in extreme cases, unconsciousness and even death. Studies have linked endosulfan to smaller testicles, lower sperm production, an increase in the risk of miscarriages and autism. Endosulfan is a potent environmental pollutant and is especially toxic to fish and other aquatic life. It also affects birds, bees, earthworms, and other beneficial insects. Endosulfan travels such long distances that it has been found in Sierra Nevada lakes and on Mt. Everest. This persistent pesticide can also migrate to the Poles on wind and ocean currents where Arctic communities have documented contamination. “It’s time for the U.S. to step up to the plate and get rid of endosulfan,” notes Karl Tupper, Ph.D., staff scientist with Pesticide Action Network North America (PANNA). “EPA’s review of endosulfan has been dragging on for years. Since 2006 they’ve […]

(Beyond Pesticides October 22, 2009) At least seven million inhabitants of Moldavia and Ukraine are endangered by 10,000 tons of old pesticides. This has been reported by the International HCH and Pesticides Association (IHPA). According to the organization the EU must act as fast as possible to disarm this ”˜biggest chemical time bomb of Europe.’ This position was adopted at the closure of the 10th HCH & Pesticides Forum of the IHPA in the Czech Republic. During the congress, it became known that in the former Kalush factory in the west of Ukraine there is a stockpile of no less than 10,000 ton of superfluous Hexachlorobenzene (HCB). The factory location along the Dniester River makes the situation extremely hazardous: a single flood and the high concentrations of poison would pollute the natural habitat of some seven million people in the west of Ukraine and Moldavia. Pesticides are threatening tens of millions of people living throughout Europe, Central Asia, and the former Soviet Union, accordding to the statement. There is an estimated 178,000 to 289,000 tons of obsolete pesticides stockpiled throughout the European Union, Southeast Europe, and the former Soviet Union. Ukraine alone has 4,500 storage locations with over 30,000 tons […]

(Beyond Pesticides, October 16, 2009) On October 14th, Earthjustice and Farmworker Justice filed a petition asking the U.S. Environmental Protection Agency (EPA) to set safety standards protecting children who grow up near farms from the harmful effects of pesticide drift. The groups are also asking the agency to adopt an immediate no-spray buffer zone around homes, schools, parks and daycare centers for the most dangerous and drift-prone pesticides, organophosphates. The petition was filed by the public interest law firms on behalf of farmworker groups: United Farm Workers, Oregon-based Pineros y Campesinos Unidos del Noreste, California Rural Legal Assistance Foundation, and the Farm Labor Organizing Committee, AFL-CIO as well as Physicians for social Responsibility, Washington-based Sea Mar Community Health Center, Pesticide Action Network North America, and MomsRising.org. Specifically, the petition states that the EPA has failed to address the facts that children are particularly vulnerable to pesticides according findings by the National Academy of Sciences (NAS) in 1993. Congress took recommendations from NAS and passed the Food Quality Protection Act in1996, requiring EPA to “ensure that there is a reasonable certainty that no harm will result to infants and children from aggregate exposure” to pesticides. However, while EPA has made some […]

(Beyond Pesticides, September 18, 2009) Previously documented in the Potomac River, which flows through downtown Washington, DC, the occurrence of “intersex” fish is now found to be nationwide. U.S. Geological Survey (USGS) researchers published their study, “Widespread occurrence of intersex in black basses from U.S. rivers” in the online edition of Aquatic Toxicology. USGS researchers examined 16 different species of fish across the U.S. between 1995 and 2004. The condition of intersex fish, male fish producing eggs, is most commonly found in smallmouth and largemouth bass. One third of male smallmouth bass and one fifth of the male largemouth bass are intersex. Scientists tested sites in the Apalachicola, Colorado, Columbia, Mobile, Mississippi, Pee Dee, Rio Grande, Savannah, and Yukon River basins. Research shows intersex fish in approximately one-third of all examined sites. The only site where researchers found no intersex fish is the Yukon River basin. While the study did not look for the causes for intersex fish, scientists believe endocrine disruptors, chemicals that interfere with the body’s hormonal systems, are certainly to blame. “We know that endocrine-active compounds have been associated with intersex in fish, but we lack information on which fish species are most sensitive to such compounds, […]

(Beyond Pesticides, August 17, 2009) The four-day testing period the U.S. Environmental Protection Agency (EPA) commonly uses to determine ”˜safe’ levels of pesticide exposure for humans and animals could fail to account for the long-term effects of toxic chemicals, University of Pittsburgh researchers report in the September edition of Environmental Toxicology and Chemistry. The team found that the highly toxic pesticide endosulfan, a neurotoxin banned in several nations but still used extensively in U.S. agriculture, can exhibit a “lag effect” with the fallout from exposure not surfacing until after direct contact has ended. The findings build on a 10-year effort by Rick Relyea, Ph.D., an associate professor of biological sciences in Pitt’s School of Arts and Sciences, to understand the potential links between the global decline in amphibians, routine pesticide use, and the possible threat to humans in the future. The team exposed nine species of frog and toad tadpoles to endosulfan levels “expected and found in nature” for the EPA’s required four-day period, then moved the tadpoles to clean water for an additional four days, Jones reported. Although endosulfan was ultimately toxic to all species, three species of tadpole showed no significant sensitivity to the chemical until after they […]

(Beyond Pesticides, August 10, 2009) The multinational chemical company Bayer has stated that it will end distribution of the pesticide endosulfan in 2010, and to replace the toxic pesticide with safer alternatives. The decision follows an innovative action in 16 countries, led by Pants to Poverty, the organic and Fairtrade underwear company, and its coalition of partners including Pesticide Action Network, Fairtrade Alliance Kerala and Zameen Organic. In a letter addressed to Coalition Against Bayer Dangers, Bayer said: “We plan to stop the sale of the substance endosulfan by the end of 2010 in all the countries where it is still legally available.” The letter, signed by Bayer CropScience’s head of investor relations, Judith Nestmann, said endosulfan would be replaced by alternatives “with a significantly better risk profile”. Bayer’s decision comes after years of global campaigning by the PAN Network and its partners and allies against this persistent pesticide, which is linked to autism, birth defects and male reproductive harm, as well as deaths and acute injuries to farmers through direct contact. It is banned in over 60 countries including those in the European Union. In the United States endosulfan is used primarily on cotton in the state of California […]

(Beyond Pesticides, July 23, 2009) A new study published in the August 2009 issue of Environmental Toxicology and Chemistry found that insecticides used in highly populated agricultural areas of California’s Central Valley affect amphibians that breed in the Sierra Nevada Mountains to the east. This study adds to the increasing evidence that pesticides impact areas and wildlife species that are miles from sources of pesticide application. Researchers from the Cooperative Wildlife Research Laboratory, Southern Illinois University and U.S. Geological Survey (USGS) examined the chronic toxicity of two of the insecticides most commonly used in the Central Valley- chlorpyrifos and endosulfan, to larval Pacific treefrogs (Pseudacris regilla) and foothill yellow-legged frogs (Rana boylii), the amphibians with declining populations that live and breed in meadows surrounding the Sierra Nevada. The results are discussed in “Toxicity of Two Insecticides to California, USA, Anurans and Its Relevance to Declining Amphibian Populations.” The study used laboratory testing to examine how the insecticides affected the two frogs at environmentally realistic concentrations. During testing, tadpoles were observed at various stages of development to see how the insecticides affected their growth and health. The researchers found that endosulfan was more toxic than chlorpyrifos to both species, and tadpoles […]

(Beyond Pesticides, July 10, 2009) The Center for Biological Diversity notified the U.S. Environmental Protection Agency (EPA) earlier this week of its intent to file suit against the agency for failing to consider impacts to the polar bear and its Arctic habitat from toxic contamination resulting from pesticide use in the U.S. Pesticides registered by EPA for use in the U.S. are known to be transported to the Arctic via various atmospheric, oceanic, and biotic pathways. Such pesticides are biomagnified with each step higher in the food web, reaching some of their greatest concentrations in polar bears, the apex predators of the Arctic. A body of literature demonstrates the far-reaching effects of commonly used pesticides that are suspected endocrine disruptors and persistent organic pollutants, such as atrazine, 2,4-D, lindane, endosulfan, and permethrin, on global ecosystems. These pesticides, among others, and related contaminants have been linked to suppressed immune function, endocrine disruption, abnormalities in reproductive organs, hermaphroditism, and increased cub mortality in polar bears. Human subsistence hunters in the Arctic, who share the top spot on the food web with the polar bear, also face increased risks from exposure to these contaminants. “The poisoning of the Arctic is a silent crisis […]

(Beyond Pesticides, January 14, 2009) Two-headed bass found in the Noosa River are at the center of a controversy surrounding pesticide drift from neighboring farms in Queensland, Australia. The pesticides, endosulfan and carbendazim, have been implicated in the contamination of the river, which has yielded thousands of chronically deformed fish. Experts believe that the mutated fish, which survive only 48 hours after hatching, are the victims of pesticide drift from neighboring macadamia nut farms that routinely use endosulfan and the fungicide, carbendazim. Aquatic health expert and vice-president of the Australian College of Veterinarian Scientists’ Aquatic Animal Health Chapter, Matt Landos, PhD, has been investigating the phenomenon and concludes that there were no other probable causes to explain the fish and larval mortality. Dr. Landos documented evidence and completed a report which was sent to the state’s Department of Primary Industries and Fisheries last year. “The timing between the mist spraying and the affected larvae fits hand in glove,” Dr. Landos said. His report also found that chickens, sheep and horses raised at nearby fish hatcheries are also recording abnormally high levels of fetal deaths and birth defects. Gwen Gilson, who runs a Boreen Point fish hatchery, says she has observed […]

(Beyond Pesticides, December 18, 2008) The New Zealand’s Environmental Risk Management Authority (ERMA) has announced it will ban the controversial organochlorine pesticide endosulfan, effective January 16, 2009. Endosulfan, already banned in numerous countries including all the European Union countries, is an insecticide used on a wide range of fruits and vegetables and also on athletic fields in New Zealand. Illegal residues have been found in beef destined for South Korea, resulting in enormous costs for New Zealand exporters. Use of endosulfan for agriculture continues in the U.S., despite causing severe health and environmental problems. A coalition of groups, including the Pesticide Action Network Aotearoa New Zealand (PAN ANZ), Soil and Health Association and Safe Food Campaign, have long campaigned for the banning of endosulfan. Earlier this year, the three organizations carried out a number of residue tests on produce to draw attention to the extent of endosulfan residues, especially in tomatoes. “We are delighted that ERMA has overturned its earlier ”˜proposed’ decision to keep using this pesticide,” stated Meriel Watts, Ph.D., co-coordinator of PAN ANZ. “It would have been deeply embarrassing for New Zealand to continue its use when the pesticide has entered the process for a global ban under […]

(Beyond Pesticides, December 8, 2008) A new study by a National Institute for Occupational Safety and Health (NIOSH) researcher finds the pesticide poisoning incidence rate among U.S. agricultural workers is thirty-nine times higher than the incidence rate found in all other industries combined. The study, “Acute Pesticide Poisoning Among Agricultural Workers in the United Sates, 1998-2005,” published in the December issue of the American Journal of Industrial Medicine, is believed to be the first detailed multi-state assessment of acute pesticide poisonings among agricultural workers. From 1998 to 2005, a total of 3,271 cases of acute occupational pesticide-related illness/injury among agricultural workers were identified in ten states. According to EPA, the Worker Protection Standards are designed to reduce the risk of injury or illness to agricultural field workers resulting from exposure to pesticides. Although the WPS was expanded in 1995 and in 2005 EPA developed a new WPS How to Comply (HTC) Manual, the NIOSH findings indicate that agricultural workers continue to have an elevated risk for acute pesticide poisoning. Furthermore, female agricultural workers experienced nearly twice the risk of pesticide poisoning of male agricultural workers. The most common factors that contributed to pesticide exposure included off-target drift, early reentry into […]

(Beyond Pesticides, November 17, 2008) A toxic soup of the most commonly used pesticides frequently detected in nature can adversely affect the environment and decimate amphibian populations even if the concentration of the individual chemicals are within limits considered safe, according to University of Pittsburgh research published in the online edition of Oecologia. The results of this study build on a nine-year effort to understand potential links between the global decline in amphibians, routine pesticide use, and the possible threat to humans in the future. Amphibians are considered an environmental indicator species because of their unique sensitivity to pollutants. Their demise from pesticide exposure could foreshadow the fate of less sensitive animals, according to study author Dr. Rick Relyea, Ph.D., an associate professor of biological sciences in the University of Pittsburgh’s School of Arts and Sciences. Leopard frogs, in particular, are vulnerable to contamination; once plentiful across North America, their population has declined in recent years as pollution and deforestation has increased. Dr. Relyea exposed gray tree frog and leopard frog tadpoles to small amounts of the ten pesticides that are widely used throughout the world. Dr. Relyea selected five insecticides: carbaryl, chlorpyrifos, diazinon, endosulfan, and malathion; and five herbicides: […]