Chlorpyrifos and neurodevelopmental effects: a literature review and expert elicitation on research and policy

Abstract

BackgroundOrganophosphate pesticides are widely used on food crops grown in the EU. While they have been banned from indoor use in the US for a decade due to adverse health effects, they are still the most prevalent pesticides in the EU, with Chlorpyrifos (CPF) being the most commonly applied. It has been suggested CPF affects neurodevelopment even at levels below toxicity guidelines. Younger individuals may be more susceptible than adults due to biological factors and exposure settings.MethodsA literature review was undertaken to assess the evidence for CPF contributing to neurodevelopmental disorders in infants and children. Other literature was consulted in order to formulate a causal chain diagram showing the origins, uptake, and neurological effects of animal and human exposure to CPF.The causal chain diagram and a questionnaire were distributed online to scientific experts who had published in relevant areas of research. They were asked to assess their confidence levels on whether CPF does in fact contribute to adverse neurodevelopment outcomes and rate their confidence in the scientific evidence. A second questionnaire queried experts as to which kind of policy action they consider justifiable based on current knowledge. In a special workshop session at the EuroTox congress in Dresden in 2009 the results of both questionnaires were further discussed with invited experts, as a basis for a policy brief with main messages for policy makers and stakeholders.ResultsMost experts who responded to the first questionnaire felt that there was already enough evidence to support a ban on indoor uses of CPF in the EU. However, most felt additional research is still required in several areas. The responses from the first questionnaire were used to formulate the second questionnaire addressing the feasibility of government action. In turn, these expert participants were invited to attend a special session at the EuroTox congress in Dresden in 2009.ConclusionsSome of the evidence that CPF contributes to neurodevelopmental disorders is still disputed among experts, and the overall sense is that further research and public awareness are warranted. There have been campaigns in North America making the potential exposure concerns known, but such information is not widely known in the EU. The ability of government action to produce change is strongly felt in some quarters while others believe better knowledge of consumer use trends would have a greater impact.

Phenotypic malignant changes and untargeted lipidomic analysis of long-term exposed prostate cancer cells to endocrine disruptors

“…Although it has been described as moderately toxic to humans, it remains one of the most widely used organophosphate insecticides. Exposure to CPF has been linked to neurobehavioral and neurodevelopmental effects (Saunders et al, 2012;Grandjean and Landrigan, 2014). Concerning prostate cancer, a very large prospective cohort study reported a correlation between chlorpyrifos exposure and prostate cancer risk in farmers (Alavanja et al, 2003).…”

Chronic exposure to chlorpyrifos triggered body weight increase and memory impairment depending on human apoE polymorphisms in a targeted replacement mouse model

“…The highly-lipophilic organophosphorus (OPs) compound chlorpyrifos (CPF) is one of the most frequently used non-persistent pesticides worldwide, even though the US Environmental Protection Agency (EPA) banned it from residential use in 2001, and its decreasing use in Europe [65]. It is used extensively because of its effective and cost-competitive broad spectrum of activity, and has often been selected to replace persistent organochlorinated compounds [41].…”

Biosensor Technology for Pesticides—A review

“…Steep increase in the incidences of cancer, chronic kidney diseases, suppression of the immune system, sterility among males and females, endocrine disorders, neurological and [57] Reproductive system [58] Immune system [59] Hexachlorohexane Immune system [60] Liver [57] Blood dyscrasias anemia [61] Reproductive system [62] Organophosphates Chlorpyrifos Immune system [63] AChE activity in developing fetus [64] Mammalian cell cultures [65] Neurodevelopmental disorders [66] Methyl parathion Neurotoxic effects (CNS) [21,67,68] Malathion Reproductive system [69] AChE activity [70] Lipid peroxidation [71] Genotoxic effects [72] Pyrethroids Allethrin, Permethrin Neurotoxic effects and NA + -K + ions channels [73,74] Carbamates DDT dichlorodiphenyltrichloroethane, AChE acetylcholinesterase, CNS central nervous system, MCPA 4-chloro-2-methyl phenoxyacetic acid, MCPP 2-(4-chloro-2 methylphenoxy) propionic acid, 2,4-D 2,4-dichlorophenoxy acetic acid behavioral disorders, especially among children, have been attributed to chronic organophosphate pesticide poisoning [83]. As mentioned earlier, organophosphorus compounds halt the activity of enzyme acetylcholinesterase by changing its structure and function.…”