(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 15, 2010) Every year, more than 10,000 kids are poisoned by rodenticides (pesticides made to kill rodents) and virtually all of the calls to U.S. poison control centers concern children under six. New rules and restrictions set by the U.S. Environmental Protection Agency (EPA) will go into effect next June in an attempt to prevent incidents involving children, but do not go far enough to protect children or wildlife. EPA has known for a generation that children have easy access to these super-toxic rat poisons. Every year, more than 10,000 kids are getting a hold of them, with Black and Hispanic children living below the poverty line being disproportionately affected. Records show that the EPA is aware that children have been getting into these poisons in significant numbers, according to data since 1983. Between 2004 and 2008, U.S. poison control centers continued to receive 10,000 to 14,000 calls about the rat killers annually. EPA has estimated that these incidents reported to poison control centers probably account for only about one-fourth of all exposures. On average, about 3,700 of these cases are treated by medical professionals each year, according to reports of the American Association of Poison Control […]

(Beyond Pesticides, December 1, 2010) Several fishing and environmental conservation groups are suing the U.S. Environmental Protection Agency (EPA) for failing to limit the use of six agricultural pesticides to protect salmon. Restrictions on the use of six pesticides in Oregon, Washington and California shown to harm endangered salmon and steelhead, were ordered after a court found that EPA violated the Endangered Species Act (ESA) by failing to restrict the pesticides from entering salmon habitat. However EPA has failed to act to restrict the pesticides. The lawsuit, filed in U.S. District Court in Washington is the fourth lawsuit the plainstiffs -Northwest Coalition for Alternatives to Pesticides, Pacific Coast Federation of Fishermen’s Associations; Institute for Fisheries Resources and Defenders of Wildlife- brought against the EPA to restrict the pesticides diazinon, malathion, chlorpyrifos, carbaryl, carbofuran and methomyl in streams of endangered salmon and steelhead. The plaintiffs seek a judgment declaring that EPA’s failure to implement the organophosphate (OP) and carbamate biological opinions issued by the National Marine Fisheries Service (NMFS) violates the ESA, and a judgment declaring that EPA is taking listed salmonids in violation of the ESA. The lawsuit seeks an order vacating and enjoining EPA’s authorization of the uses of […]

(Beyond Pesticides, October 19, 2010) In addition to the ongoing investigation into the death of nearly 1,000 lobsters last fall around waters in New England and Canada, Environment Canada is now investigating the possible release of a pesticide that is not permitted for use in Canada. The pesticide, cypermethrin, is used in the U.S., including Maine, to control sea lice outbreaks in salmon farms, a practice under investigation. Cypermethrin is toxic to lobsters, and fishermen associations have been calling for the elimination of the use of pesticides in the marine environment. Fish farmers have been challenged in controlling sea lice outbreaks this summer, particularly in the upper Passamaquoddy Bay area. They have been using other chemicals to control the outbreaks, including hydrogen peroxide, Salmosan (azamethiphos), SLICE (emamectin benzoate) and Calicide (teflubenzuron). New Brunswick aquaculture organizations have maintained that fish farmers do not use cypermethrin, which is not permitted for use there. The New Brunswick Salmon Growers Association referred to the cocktail of pesticides used on salmon farms as “medicine” and referred to salmon farming techniques as “natural.” However, shoddy farming practices, such as growing too many fish per site and having too many sites in the same area, can lead […]

(Beyond Pesticides, September 8, 2010) The U.S. Environmental Protection Agency (EPA) has received a new Biological Opinion from the National Marine Fisheries Service (NMFS) with a finding that the application of products containing any of 12 organophosphate (OP) pesticides are likely to jeopardize federally listed threatened or endangered Pacific salmon and steelhead and their designated critical habitat. The 12 OPs addressed in this Biological Opinion, issued under the Endangered Species Act, are azinphos-methyl, bensulide, dimethoate, disulfoton, ethoprop, fenamiphos, methamidophos, methidathion, methyl parathion, naled, phorate, and phosmet. This opinion concludes that EPA’s registration of pesticides containing bensulide, dimethoate, ethoprop, methidathion, naled, phorate, and phosmet are each likely to jeopardize the continued existence of one or more of the 28 endangered and threatened Pacific salmonids and are each likely to destroy or adversely modify designated critical habitat for one or more of the 28 threatened and endangered salmonids. NMFS reached this conclusion because predicted concentrations of these seven pesticides in salmonid habitats, particularly in floodplain habitats, are likely to cause adverse effects to at least one listed Pacific salmonids including significant reductions in growth or survival. EPA’s registration of bensulide, dimethoate, ethoprop, methidathion, naled, phorate, and phosmet is also likely to result […]

(Beyond Pesticides, August 30, 2010) AquaBounty Technologies Inc.. a small biotechnology firm based in Waltham, Massachusetts, is seeking FDA approval for a genetically engineered salmon, hoping to do for aquaculture what biotech giants such as Monsanto have done for agronomy. Currently, the vast majority of US soybeans, corn, and cotton are genetically engineered, but this would be the first commercially available genetically engineered food animal. While AquaBounty argues their fish will help feed the world, many are leery of “frankenfish” being introduced into the food supply. If the proliferation of genetically engineered crops in the U.S. is any indication, the introduction of genetically engineered animals into the food supply will fail to produce an increase in yield. AquaBounty has invested $50 million over 14 years to develop AquAdvantage Fish. AquAdvantage Salmon (AAS) unlike conventional salmon grows year around reaching market weight in 18 months instead of 36, and consuming 25% less food over its lifetime. The variety was developed by inserting part of a gene from an Ocean Pout, an eel-like fish, into the growth gene of a Chinook salmon. The blended genetic material is then injected into the fertilized egg of a North Atlantic salmon. According to AquaBounty CEO […]

(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 24, 2010) Our food purchases have a direct effect on the health of our environment and those who grow and harvest what we eat. Beyond Pesticides launched its Organic Food: Eating with a Conscience guide, which shows consumers why, according to the group, “food labeled organic is the right choice.” Jay Feldman, executive director of Beyond Pesticides, said, “In addition to serious health questions linked to actual residues of toxic pesticides on the food we eat, our food buying decisions support or reject hazardous agricultural practices, protection of farmworkers, and stewardship of the earth.” The Eating with a Conscience guide explains to consumers the effect they are having on health and the environment when they purchase food grown with chemical-intensive methods, even if a large number of residues do not remain on the finished food product. The group points to USDA organic certification as “the only system of food labeling that is subject to independent public review and oversight, assuring consumers that toxic, synthetic pesticides used in conventional agriculture are replaced by management practices focused on soil biology, biodiversity, and plant health.” “Organic practices under the Organic Foods Production Act eliminate commonly used toxic chemicals in the […]

(Beyond Pesticides, June 1, 2010) Atrazine, one of the most commonly used herbicides in the world, has been shown to affect reproduction of fish at concentrations below U.S. Environmental Protection Agency’s (EPA) water-quality guideline, according to a new U.S. Geological Survey (USGS) study. “Concentrations of atrazine commonly found in agricultural streams and rivers caused reduced reproduction and spawning, as well as tissue abnormalities in laboratory studies with fish,” said USGS scientist Donald Tillitt, Ph.D., the lead author of the study, “Atrazine Reduces Reproduction in Fathead Minnow (Pimephales promelas)” published in Aquatic Toxicology. Fathead minnows were exposed to atrazine at the USGS Columbia Environmental Research Center in Columbia, Missouri, and observed for effects on egg production, tissue abnormalities and hormone levels. Fish were exposed to concentrations ranging from zero to 50 micrograms per liter of atrazine for up to 30 days. All tested levels of exposure are less than the EPA Office of Pesticides Aquatic Life Benchmark of 65 micrograms per liter for chronic exposure of fish. Study results show that normal reproductive cycling was disrupted by atrazine and fish did not spawn as much or as well when exposed to atrazine. Researchers found that total egg production was lower in […]

(Beyond Pesticides, May 19, 2010) EPA has announced plans to place additional limitations on the use of three N-methyl carbamate pesticides — carbaryl, carbofuran and methomyl — to protect endangered and threatened salmon and steelhead in California, Idaho, Oregon and Washington, in compliance with the Endangered Species Act. The decision comes after manufacturers of the chemicals diazinon, malathion and chlorpyrifos refused to adopt the limits voluntarily. The new protections are based on recommendations by the National Marine Fisheries Service (NMFS) in their April 2009 Biological Opinion relative to use of the three pesticides to ensure no likely jeopardy to 28 threatened or endangered Pacific salmon and steelhead species. In a May 14, 2010 letter to NMFS, EPA explains how the Agency plans to achieve protection goals through the methods outlined by NMFS in the Biological Opinion or by alternative methods that EPA’s scientific analyses determined will achieve the same purpose. For example, EPA will require pesticide drift buffers adjacent to salmon and steelhead habitat but will impose different width buffers, some wider and others narrower than those recommended by NMFS, depending on factors that affect how far the pesticide might drift from the application site. In correspondence to the EPA […]

(Beyond Pesticides, March 11, 2010) The New York State Department of Environmental Conservation (DEC) determined that a pair of bald eagles were killed and a host of other wildlife were injured after an Allegany County farmer applied a highly toxic pesticide that has been canceled for use by the U.S. Environmental Protection Agency (EPA). Following an investigation, the state DEC determined that the two bald eagles were poisoned after ingesting the improperly applied pesticide Furadan, or carbofuran, on his farm. The farmer and landowner, Richard Sekoll, was charged with and pleaded guilty to violating state pesticide laws and fish and wildlife laws and paid $3,000 in fines. After receiving a call that two dead bald eagles were found near the Genesee River last fall, DEC began an investigation and sent the eagles to the department’s Wildlife Pathology Unit. Lab results showed that the birds died of poisoning from consumption of carbofuran, which occurred after the eagles consumed prey that had ingested the pesticide. State officials with the DEC’s Division of Pesticides and the Division of Wildlife, as well as the U.S. Fish and Wildlife Service assisted in the investigation, which found that a farm within 500 yards of where the […]

(Beyond Pesticides, March 3, 2010) A recently published study in the Proceedings of the National Academy of Sciences finds that male frogs exposed to the herbicide atrazine can become so completely female that they can mate and lay viable eggs. This latest study adds to the growing scientific evidence which shows that atrazine, one of the most common herbicides used in the U.S., disrupts the development and behavior of aquatic animals, and negatively effects their immune, hormone, and reproductive systems. The study, “Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis),” led by Tyrone Hayes, PhD, at the University of California, Berkeley, demonstrates the reproductive consequences of atrazine exposure in adult amphibians. Dr. Hayes and other researchers examined a group of 40 African clawed frogs, all of which carried male chromosomes. As tadpoles, the frogs were put in water with 2.5 parts per billion (ppb) of atrazine — a concentration within federal drinking water standards. Atrazine-exposed males were both demasculinized (chemically castrated) and completely feminized as adults. Exposed genetic males developed into functional females that copulated with unexposed males and produced viable eggs. The eggs produced were all male offspring since both parents contributed male […]

(Beyond Pesticides, February 16, 2010) Pyrethroids, among the most widely-used home pesticides, are winding up in California rivers at levels toxic to some stream-dwellers, possibly endangering the food supply of fish and other aquatic animals, according to a study by researchers at the University of California, Berkeley, and Southern Illinois University (SIU). The study, “Urban and Agricultural Sources of Pyrethroid Insecticides to the Sacramento-San Joaquin Delta of California,” in the journal Environmental Science & Technology, is the first published work to document toxic levels in the water column as well as in the sediments at the bottom of streams. Pyrethroid insecticides, commonly used to kill ants and other insects around the home, have been found in street runoff and in the outflow from sewage treatment plants in the Sacramento, California area. The insecticide ended up in two urban creeks, the San Joaquin River and a 20-mile stretch of the American River, traditionally considered to be one of the cleanest rivers in the region. Although the pyrethroid levels were low, around 10-20 parts per trillion, they were high enough to kill a test organism similar to a small shrimp that is used to assess water safety. “These indicator organisms are ‘lab […]

(Beyond Pesticides, February 8, 2010) The Center for Biological Diversity filed a notice of intent to sue the Environmental Protection Agency (EPA) last week. The lawsuit argues that EPA violated the Endangered Species Act when it approved 394 pesticides known to be harmful to humans and wildlife, without consulting with wildlife regulatory agencies as to the pesticides’ effects on endangered species. By registering pesticides known to harm migratory birds the EPA has also violated the Migratory Bird Treaty Act, according to the suit. The pesticides named in the suit pose a danger not only to wildlife, but to human health as well. Some of the pesticides named include 2,4-D the most commonly used pesticide in the nonagricultural sector, atrazine, triclosan, and pyrethrins. Jeff Miller, conservation advocate at the Center for Biological Diversity, said, “It’s time for the Environmental Protection Agency to finally reform pesticide use to protect both wildlife and people…Many endangered species most affected by toxic pesticides are already struggling to cope with habitat loss and rapid climate changes. For too long this agency’s oversight has been abysmal, allowing the pesticide industry to unleash a virtual plague of toxic chemicals into our environment.” The suit names 887 threatened and […]

(Beyond Pesticides, December 18, 2009) Biologists are finding that short-term, seasonal exposure to pesticides in rivers and basins limit the growth and size of wild salmon populations. Along with the widespread deterioration of salmon habitats, these findings show that exposure to commonly used pesticides continue to detriment the recovery of the salmons’ populations. The findings can be found in the study, “A fish of many scales: extrapolating sublethal pesticide exposures to the productivity of wild salmon populations,” in the December 2009 issue of the Ecological Society of America (ESA) journal, Ecological Applications. “Major efforts are currently underway to restore Pacific salmon habitats in an effort to recover depressed populations,” says David Baldwin, Ph.D., of the National Oceanic and Atmospheric Administration (NOAA), who co-authored the study with NOAA colleagues, “However, not much research has been done to determine the importance of pollution as a limiting factor of ESA-listed species.” The researchers studied the impact of pesticides, such as diazinon and malathion, on individual salmon using pre-existing data, and then devised a model to calculate the productivity and growth rate of the population. They used several exposure scenarios to reflect realistic pesticide use across various landscapes and over time. “An important aim […]

(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, September, 15, 2009) On September 11, 2009, the Environmental Protection Agency (EPA) announced plans to place additional limitations on the use of three organophosphate pesticides ”” chlorpyrifos, diazinon and malathion ”” to protect endangered and threatened salmon and steelhead in California, Idaho, Oregon and Washington. The announcement comes in response to a series of lawsuits brought by Pacific Coast Federation of Fishermen’s Associations (PCFFA), the Northwest Coalition for Alternatives to Pesticides, and other salmon advocates, with legal representation from Earthjustice, aimed at removing toxic pesticides from salmon spawning streams throughout the northwest. In response to the litigation, the National Marine Fisheries Service (NMFS) in November of 2008 released a “biological opinion” that set forth a plan for protecting Pacific salmon and steelhead from three toxic organophosphate pesticides. That decision came after almost a decade of legal wrangling between salmon advocates led by Earthjustice and the federal government. The biological opinion prescribed measures necessary to keep these pesticides out of water and to protect salmon populations in Washington, Oregon, California, and Idaho. The announcement from EPA moves this work forward. Although the experts at NMFS recommended prohibiting aerial applications of the three pesticides within 1,000 feet of salmon waters […]

(Beyond Pesticides, September 8, 2009) Researchers at the University of Nebraska-Lincoln believe they may have determined the first causal relationship linking colony collapse disorder (CCD) to pathogens and other environmental stresses, including pesticides. CCD is a disappearance of honey bees that has beset beekeepers killing off more than a third of commercial honey bees in the U.S. in 2006-2007. Their study, “Changes in transcript abundance relating to colony collapse disorder in honey bees,” was published September 1, 2009 in the Proceedings of the National Academy of Sciences. The team also included researchers from the University of Illinois and the U.S. Department of Agriculture. In a nutshell, the researchers determined, by comparing the differences in gene expression in healthy and CCD colonies, the infected colonies had considerably more damage in their ribosomes. (Ribosomes function in the expression of the genetic code from nucleic acid into protein in all animal, plant and fungal cells.) The infected hives also had higher rates of picorna-like viruses, which damage the ribosome. The researchers believe the loss of ribosomal function leaves the bees susceptible to pesticides and other infections. The honey bee genome project was launched in 2006 by University of Illinois researchers. The new study […]

(Beyond Pesticides, September 2, 2009) At least 40 small birds were found dead on Sunday in Quebec City, Canada, in what residents described as a scene out of a “Hitchcock movie.” A bird feeder, stuffed with 4-aminopyridine laced corn was the culprit. The chemical was set out on the roof of a building in effort to ward off nuisance pigeons; dozens of other birds were accidentally killed, particularly bronzed grackles. While Quebec City police purport that this pesticide is legal and no charges will be made, the Quebec Environment Ministry is investigating the incident to see if exterminators followed the proper guidelines. “The wrong type of bird ended up being targeted,” Quebec City police spokeswoman Catherine Viel said. A similar event happened in Schenectady New York in 2006, when Rentokill, Inc., a local exterminator applied 4-aminopyridine in order to ward off pigeons from a hospital. This caused a “deadly rain” of pigeons to fall from the sky, closing the hospital emergency room. One of the most prominent avicides, Avitrol –the trade name for 4-aminopyridine–i s available as grain baits or powder concentrate. It repels birds by poisoning a few members of a flock, causing them to become agitated, which signals […]

(Beyond Pesticides, August 6, 2009) American Bird Conservancy has petitioned the U.S. Environmental Protection Agency (EPA) to ban the import of crops containing any residues of 13 pesticides that are banned or restricted for use in the United States. These pesticides are highly toxic to birds, but are commonly used on crops throughout Latin America where many species of U.S. migratory birds spend the winter months. In addition to the environmental risks to birds, several of these chemicals also pose a risk to agricultural workers. “Allowing residues of these hazardous pesticides on imported food gives tacit U.S. approval to foreign countries to use chemicals that are known to be deadly to U.S. migratory birds,” said Dr. Michael Fry, American Bird Conservancy’s Director of Conservation Advocacy. “EPA has an obligation under Executive Order 13186, the Migratory Bird Treaty Act, and the Endangered Species Act to ensure that migratory birds are not harmed.” Many Latin American countries that currently use these pesticides export coffee, bananas, citrus crops, and other fruits and vegetables to the United States. Agricultural areas — in particular shade coffee farms — provide valuable habitat for migratory birds, and so pesticide use in these areas can pose a significant […]

(Beyond Pesticides, July 31, 2009) A group of advocates and experts is warning that pesticide pollution from farm fields and households is contributing to the Chesapeake Bay’s decline, and may well be linked to declines in frogs across the region and intersex fish seen in the Potomac River. In a report released yesterday, the group calls on federal, state and local government to accelerate research into what threats pesticide contamination may pose to the bay, and to step up efforts to reduce such toxic pollution. “The thing that alarms us the most are the endocrine disruptors and the findings that have come out about intersex fish and frogs with reproductive problems,” said Robert SanGeorge, director of the Pesticides and the Chesapeake Bay Watershed Project. Endocrine disruptors are chemicals that mimic the natural hormones in humans or animals and can disrupt their growth and reproduction. The project is a partnership between the Maryland Pesticides Network and the Johns Hopkins Center for a Livable Future. The group’s warning and recommendations are the product of a two-year study, in consultation with scientists, public health experts, government officials, watermen, environmentalists, farmers and pest management industries. The report comes as federal and state governments attempt […]

(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 […]