(Beyond Pesticides, February 17, 2010) In the largest study of its kind, researchers searched hundreds of Salinas Valley, California homes for pesticide compounds sticking to dust layers and discovered widespread residues of 22 residential and agricultural-use products. The study, “Pesticides in Dust from Homes in an Agricultural Area,” was conducted by an investigator from the California Department of Public Health and researchers with the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) with the University of California, Berkeley. CHAMACOS began recruiting pregnant women in the Salinas Valley for a long-term study of prenatal and infant chemical and allergen exposure in 1999. The center sampled study homes in 1999 and 2000 with a modified vacuum cleaner. The most common pesticides found were permethrin (467ppb) -a popular insecticide against home insect, and chlorpyrifos (74ppb). The U.S. Environmental Protection Agency (EPA) banned chlorpyrifos for home-use in 2000, but it is still used in agriculture. Other pesticides frequently detected include the herbicide dimethyl tetrachloroterephthalate (DCPA), methomyl, diazinon and a fungicide, iprodione. Household dust concentrations are significantly associated with nearby use of these chemicals on agricultural fields in the month or season prior to sample collection. The study reported that in […]

(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, September 16, 2009) A new study published in the September issue of Archives of Neurology reports that the risk of Parkinsonism doubled with increased occupational exposure to pesticides, including eight agents associated with experimental Parkinsonism. These data add to the growing number of studies that lend credence to a causative role of certain pesticides in neurological disorders. The study, “Occupation and Risk of Parkinsonism: A Multicenter Case-Control Study,” set out to investigate occupations, specific job tasks, or exposures and risk of parkinsonism in collaboration with eight movement disorders centers in North America including, the Parkinson’s Institute, CA, Department of Neurology, Baylor College of Medicine and Department of Neurology, Beth Israel Medical Center, New York. The investigation focused on five occupations previously suggested as posing an increased risk of Parkinsonism: agriculture, education, healthcare, welding, and mining. This examination of toxicant exposures included solvents and pesticides putatively associated with Parkinsonism. 519 people with Parkinson’s disease and 511 similar people who did not have Parkinson’s were studied. Overall, the study finds that those whose jobs involve using pesticides are 80 percent more likely to develop the condition. The data reveals that any exposure to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) almost triples […]

(Beyond Pesticides, July 17, 2009) High levels of pyrethroid pesticides in the Sacramento-San Joaquin River Delta, the number one river system on America’s Most Endangered Rivers List of 2009, has been linked to heavy urbanization in the region. Leading a study to understand the collapse of the delta’s ecosystem, University of California-Berkeley toxicologist Donald Weston, Ph.D. found that these pesticides most likely reached the river from urban storm drains, collecting household pesticide disposal and runoff from lawns of 1.4 million residents in the Sacramento region. Five years ago, a study by Dr. Weston and his colleague Michael J. Lydy, Ph.D of Southern Illinois University in Carbondale found that synthetic phyrethroids were collecting in river and creek sediments at levels that are toxic to bottom dwelling fish. Current research holds that there are enough pyrethroids to kill tiny shrimp, which are said to be the first link in the aquatic food chain. Pyrethroids are synthetic versions of pyrethrin, a natural insecticide found in certain species of chrysanthemum. It initially came on the market as a ”˜safer’ alternative to the heavily regulated and highly toxic organophosphates, such as diazinon and chlorypyrifos. Despite the fact that there are plenty of effective pest control […]

(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, June 22, 2009) In April 2009, the U.S. Environmental Protection Agency (EPA) announced that it is intensifying its evaluation of spot-on pesticide products for flea and tick control for pets due to recent increases in the number of reported incidents. Adverse reactions reported range from mild effects such as skin irritation to more serious effects such as seizures and, in some cases, the death of pets. Incidents with flea and tick products can involve the use of spot-on treatments, sprays, collars and shampoos. However, the majority of the incidents reported to EPA are related to flea and tick treatments with EPA-registered spot-on products. Spot-on products are generally sold in tubes or vials and are applied to one or more localized areas on the body of the pet, such as in between the shoulders or in a stripe along the back. This advisory pertains only to EPA-registered spot-on flea and tick products; these products have an EPA registration number on the label. EPA now is evaluating all available data on the pesticides, including reports of adverse reactions, clarity of product use directions and label warnings, product ingredients, market share, and pre-market safety data submitted to the Agency. EPA says […]

(Beyond Pesticides, June 17, 2009) A new study finds that toxic pesticides, including those already banned, persist in homes. The study’s results indicate that most floors in occupied homes in the U.S. have measurable levels of insecticides that serve as sources of exposure to home dwellers. These persistent residues continue to expose people, especially vulnerable children, to the health risks associated with these chemicals. Published in Environmental Science and Technology, the study, entitled “American Healthy Homes Survey: A National Study of Residential Pesticides Measured from Floor Wipes,” was conducted as a collaboration between the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Housing and Urban Development. Five hundred randomly selected homes were sampled using alcohol wipes to collect dust from hard surface floors, mostly kitchen floor surfaces. The swipes were analyzed for 24 currently and previously use residential insecticides in the organochlorine, organophosphate, pyrethroid and phenylpyrazole classes, and the insecticide synergist piperonyl butoxide. Researchers found that currently used pyrethroid pesticides were, not surprisingly, at the highest levels with varied concentrations. Fipronil and permethrin, both currently used, were found in 40 percent and 89 percent of homes respectively. However, the researchers found that long discontinued pesticides like DDT and […]

(Beyond Pesticides, March 4, 2009) The Ontario government is set to announce sweeping new regulations that will prohibit the use of 85 chemical substances, found in roughly 250 lawn and garden products, from use on neighborhood lawns. Once approved, products containing these chemicals would be barred from sale and use for cosmetic purposes. On November 7, 2008, the Ontario government released a proposed new regulation containing the specifics of the Cosmetic Pesticides Ban Act, passed last June. Then, Ontario joined Quebec in restricting the sale and cosmetic use of pesticides but environmental and public health advocates said then that the new law preempted local by-laws and actually weakens protections in some municipalities with stronger local protections. There are over 55 municipalities in Canada where the residential use, but not sale, of pesticides is banned. The prohibition of these 85 substances is the latest step in this Act. The proposal contains: ”¢ List of pesticides (ingredients in pesticide products) to be banned for cosmetic use ”¢ List of pesticide products to be banned for sale ”¢ List of domestic pesticide products to be restricted for sale. Restricted sale products include those with cosmetic and non-cosmetic uses (i.e., a product that’s allowed […]

(Beyond Pesticides, February 23, 2009) Permethrin and lindane metabolites are found in children who use lice shampoos containing the insecticides, according to researchers affiliated with the Centers for Disease Control and Prevention. The study, “Pesticide exposure resulting from treatment of lice infestations in school-aged children in Georgia,” published in the February issue of the journal Environment International, is the first to measure children’s exposure to chemical lice treatments. The researchers collected baseline urine samples from 78 enrolled children between the ages of six to ten years of age. About one-third of those children were diagnosed with head lice and subsequently treated with at least one over-the-counter permethrin lice treatment, a prescription lindane treatment, or both. Within seven days of the insecticide application, urine samples were again collected. The permethrin exposed children had significantly higher urinary pryrethoid metabolite levels in their post-exposure urine samples. Lindane metabolites were also elevated in urine samples after treatment. Interestingly, the study states, “Exposed participants appeared to have higher pre-exposure metabolite levels — likely from multiple treatments before enrollment — than unexposed participants.” Pentachlorophenol, a metabolite of lindane, was significantly higher in the urine of those children who used a lice treatment regardless of whether it […]

(Beyond Pesticides, December 16, 2008) According to a new study, published in the December 2008 issue of Environmental Health Perspectives by researchers at Columbia University’s Mailman School of Public Health, pregnant women continue to be exposed to pesticides in the home. In fact, 75% of the sampled homes of pregnant women in inner-city New York are contaminated with piperonyl butoxide (PBO), a pesticide synergist linked to cancer and other health problems. Following the Environmental Protection Agency’s phase-out agreements with the manufacturers of organophosphate insecticides chlorpyrifos and diazinon in 2000 and 2001, the Columbia University researchers sought to determine the impact of the new regulations on pest infestation levels, pesticide use, and pesticides measured in indoor air samples. They enrolled 511 pregnant women from inner-city New York between 2000 and 2006. Permethrin, a pyrethroid insecticide; PBO, a pyrethroid synergist; chlorpyrifos; and diazinon were measured in 48-hr prenatal personal air samples. Data on pest infestation and pesticide use were collected via questionnaire. 88% of women report using pesticides during pregnancy and 55% report using higher-exposure pesticide applications (spray cans, pest bombs and/or professional pesticide applicators). Self-reported pest sightings and use of higher-exposure applications increased significantly after the regulations were implemented. PBO, cis-, […]

(Beyond Pesticides, November 3, 2008) A new study, Pyrethroid pesticides and their metabolites in vacuum cleaner dust collected from homes and day-care centers (doi:10.1016/j.envres.2008.07.022), by the U.S. Environmental Protection Agency’s (EPA) National Exposure Research Laboratory finds concentrations of 13 synthetic pyrethroids and their degradates in indoor dust collected from homes and childcare centers in North Carolina and Ohio. The study results show the extent to which hazardous pesticides are present in indoor environments and threaten the public’s health, especially the health of children. With 85 vacuum cleaner bags analyzed, permethrin was present in all 85 dust samples, at least one pyrethroid pesticide was found in 69 samples and phenothrin was found in 36 samples. According to the study findings published in the November issue of the journal Environmental Research, the median concentration of permethrin in the samples is 1454ng/g of dust. Excluding permethrin, pyrethroid conectrations are less than or equal to 100ng/g of dust. The majority of the metabolites are present in more than half of the dust samples. This is not the first time researchers have found pesticides in dust in homes. A study published in the International Journal of Hygiene and Environmental Health (208: 193-199) also found that […]

(Beyond Pesticides, September 25, 2008) Pesticides used as lice treatments can not only have extremely harmful effects on children, they are also not as effective as non- chemical treatments such as utilizing directed hot air, according to researchers. Back-to-school season often coincides with lice outbreaks, and parents should be aware of the risks involved in using lice “shampoos” that contain pesticides and informed of the viability of non-toxic alternatives. Many of the recent headlines regarding lice in schools include reference to “super lice,” which are difficult to eliminate. These lice have developed resistance to the chemicals commonly used to treat them, such as lindane, malathion and permethrin, and therefore these treatments are increasingly ineffective. Insects frequently develop resistance to pesticides, a fact that emphasizes the importance of strategies both in agriculture and public health that focus on preventing pest outbreaks and dealing with outbreaks in ways that will not lead to resistance. One such method for eliminating head lice that will not lead to resistant strains of lice is the use of hot air, which desiccates the insects and eggs, thus killing them. Researchers testing six methods of hot air application found that hot air outperforms insecticidal shampoos in killing […]

(Beyond Pesticides, April 10, 2008) Common frogs that live in suburban areas are more likely than their rural counterparts to develop reproductive abnormalities, according to David Skelly, PhD, professor of ecology at the Yale School of Forestry and Environmental Studies. This phenomenon becomes a serious concern as the frog’s mating season begins, leaving researchers to wonder: will frogs be clear on their role in the annual ritual? Research by Dr. Skelly, soon to be published, focuses on the common green frog, Rana clamitans, within the Connecticut River Valley. A total of 233 frogs were collected from various ponds and landscapes with the river valley and among them 13 percent have abnormalities occurring in their reproductive organs. In urban areas, 18 percent of the collected frogs are intersex, and in suburban areas 21 percent. Frogs collected from agricultural areas have the lowest rate of reproductive problems with just 7 percent classified as intersex. According to Dr. Skelly, the more suburban the land cover, the more likely the abnormalities. “This is the first evidence that I think anyone has provided that agriculture is doing anything but pushing those rates higher,” remarked Dr. Skelly of the intersex phenomena. In an attempt to explain […]

(Beyond Pesticides, March 10, 2008) Head lice affect an estimated 12 million people in the U.S. each year, and are rapidly becoming resistant to over-the-counter and prescription medications. Researchers at the University of Massachusetts Amherst have found that ivermectin, a compound produced by soil-dwelling bacteria, was 100 percent effective in killing head lice resistant to many standard treatments. Results were published in the January 2008 edition of the Journal of Medical Entomology. Although ivermectin is not well-absorbed through the skin, some public health advocates are concerned about its use on humans for lice and scabies. The National Pediculosis Association (NPA), a non profit agency, directs parents, health care professionals and child care providers to safer head lice control options via a standardized prevention approach focusing on routine screening, early detection and thorough combing and manual removal of lice and nits. NPA promotes this as a rational strategy over chasing lice with pesticides that offer more risk than benefit and have a well-documented history of lice resistance and failure.Most products used to treat head lice contain the insecticide pyrethrum, or its synthetic cousin permethrin, as the active ingredient. Over the past two decades, resistance to these chemicals has become a serious […]

(Beyond Pesticides, February 8, 2007) Investigators at St. Jude Children’s Research Hospital have shed new light on the suspected role of pesticides in the development of Parkinson’s disease (PD). The study, “GST expression mediates dopaminergic neuron sensitivity in experimental parkinsonism” appearing in the Proceedings of the National Academy of Sciences (January 31, 2007), illustrates the mechanism of nerve cell damage by pesticide exposure. The enzyme that prevents damage to the substantia nigra, the part of the brain where nerve cell damage associated with PD occurs, is called GST pi (“pie”). This enzyme stands like a sentry at the crossroads of several biochemical pathways, any one of which can lead to PD. GST pi protects the nerve cell from death caused by either environmental toxics, such as pesticides, or a self-destruction process called apoptosis (cell suicide), triggered by certain stressful conditions in the cell. If GST pi levels are reduced or this enzyme is overwhelmed by toxics, these nerves are at increased risk of death, according to studies in mouse models. GST pi is one of a family of similar enzymes that eliminate free radicals generated by pesticides and other chemicals. Two members of this family are present in the brain, […]