10
Dec
(Beyond Pesticides, December 10, 2012) Long-term low-level exposure to organophosphate pesticides produces lasting damage to neurological and cognitive functions, according to researchers at University College London (UCL). This research pulls data from 14 studies over the past 20 years, including more than 1,600 participants, in order to provide a quantitative analysis of the current literature on these dangerous chemicals. Lead author of the study, Sarah Mackenzie Ross, Ph.D., notes, “This is the first time anyone has analyzed the literature concerning the neurotoxicity of organophosphate pesticides, using the statistical technique of meta-analysis.” UCL’s systematic review, published in the journal Critical Reviews in Toxicology, comes to an unsettling conclusion about the hazards of constant low-level occupational exposure to organophosphates. The study notes, “The majority of well designed studies found a significant association between low-level exposure to [organophosphates] and impaired neurobehavioral function which is consistent, small to moderate in magnitude and concerned primarily with cognitive functions such as psychomotor speed, executive function, visuospatial ability, working and visual memory.” In other words, low-level exposure had significant detrimental effect on working memory and information processing. The researchers are hopeful that the results of their analysis will be used to inform governments performing reviews on the […]
Posted in Chemicals, Developmental Disorders, Disease/Health Effects, Learning Disabilities, Nervous System Effects, organophosphate | No Comments »
10
Aug
(Beyond Pesticides, August 10, 2012) A new study is the first to find a difference between how boys and girls respond to prenatal exposure to the insecticide chlorpyrifos. Researchers at the Columbia Center for Children’s Environmental Health (CCCEH) at the Mailman School of Public Health found that, at age 7, boys had greater difficulty with working memory, a key component of IQ, than girls with similar exposures. On the plus side, having nurturing parents improved working memory, especially in boys, although it did not lessen the negative cognitive effects of exposure to the chemical. Results are published online in the journal Neurotoxicology and Teratology. In 2011, research led by Virginia Rauh, ScD, Co-Deputy Director of CCCEH, established a connection between prenatal exposure to chlorpyrifos and deficits in working memory and IQ at age 7. Earlier this year, a follow-up study showed evidence in MRI scans that even low to moderate levels of exposure during pregnancy may lead to long-term, potentially irreversible changes in the brain. The latest study, led by Megan Horton, PhD, explored the impact of sex differences and the home environment on these health outcomes. Dr. Horton and colleagues looked at a subset of 335 mother-child pairs enrolled […]
Posted in Children/Schools, Chlorpyrifos, Developmental Disorders | No Comments »
15
Jun
(Beyond Pesticides, June 15, 2012) Researchers at the Duke University School of Medicine have developed a laboratory screening system for detecting neurotoxic chemicals and successfully tested it on more than 1,400 potential toxicants. The study confirms the high toxic activity of the chemical piperonyl butoxide (PBO), a chemical “synergist” used to increase the potency of more than 700 insecticides, including synthetic pyrethroids widely used in mosquito and community spray programs and for home use. The study, entitled “The Insecticide Synergist Piperonyl Butoxide Inhibits Hedgehog Signaling: Assessing Chemical Risks,” was published in the May 2012 edition of the journal Toxicological Sciences. The testing shows that PBO disrupts a biological signaling system that is “critical in neurological development,” the researchers reported in the abstract of their paper. The study finds that the disruption of this critical pathway “may be the molecular basis for profound developmental defects in children exposed in utero to PBO.” Piperonyl butoxide is not itself classified as a pesticide, but companies combine it with insecticides to increase their potency. PBO came into widespread use when the U.S. Environmental Protection Agency (EPA) phased out chlorpyrifos and other organophosphate pesticides nearly a decade ago after determining that they posed a risk […]
Posted in Developmental Disorders, Nervous System Effects, Piperonyl butoxide (PBO) | 1 Comment »
02
May
(Beyond Pesticides, May 2, 1012) New research published online at the Proceedings of the National Academy of Sciences reports that babies exposed in the womb to a commonly used insecticide have brain abnormalities after birth. The insecticide, chlorpyrifos (used in agriculture, mosquito control, and golf course management) , is well documented as inducing neurodevelopmental abnormalities in infants exposed in their mother’s womb, including ADHD, cognitive deficits, and serious learning, behavioral or emotional disorders. Entitled, “Brain anomalies in children exposed prenatally to a common organophosphate pesticide,” the study investigated associations between chlorpyrifos exposure and brain morphology using magnetic resonance imaging in 40 New York City children. It found significant associations of prenatal exposure, at standard use levels, with structural changes in the developing human brain, including enlargement of superior temporal, posterior middle temporal, and enlarged superior frontal gyrus, gyrus rectus, cuneus, and precuneus along the mesial wall of the right hemisphere. These areas of the brain impacted are related to attention, language, reward systems, emotions and control may be affected by the chemical. Twenty high-exposure children (upper third of chlorpyrifos concentrations in umbilical cord blood) were compared with 20 low-exposure children. The children, ages 6-11 years, considered to have a high […]
Posted in Birth defects, Chlorpyrifos, Developmental Disorders | No Comments »
