The latest demand seems to be that chlorpyrifos be banned in the European Union. Or, in what amounts to much the same result, it shouldn’t receive approval for use in an upcoming review. Well, maybe it shouldn’t. There are, after all, things that are indeed harmful and which we shouldn’t allow to happen to human beings. Socialism say. The question is, is chlorpyrifos one of those things?
The argument is that there’s a link between chlorpyrifos use and autism. There’s even a new paper discussing whether this might be the case.
The prevalence of autism has increased from 1 in 150 in 2002 to 1 in 59 in 2014 (Autism and Developmental Disabilities Monitoring Network Surveillance Year 2002 Principal Investigators 2007; Baio et al. 2018; Centers for Disease Control and Prevention 2017b). Although genetics are an important risk factor, they would not account for the dramatic rise in prevalence during this span in time, nor do changes in diagnostic criteria (Hertz-Picciotto and Delwiche 2009; Hertz-Picciotto et al. 2018b; King and Bearman 2009). Growing evidence suggests environmental factors and gene–environment interactions contribute to the etiology of the disorder (Frazier et al. 2014; Hallmayer et al. 2011). Some autism-related genes may be targeted by environmental pollutants, including pesticides, heavy metals, bisphenol A (BPA), phthalates, and many other chemicals in food, cosmetics, or household products (Carter and Blizard 2016). Further, evidence suggests that autism diagnosis is associated with variants in genes involved in the elimination of toxic chemicals from the body, which potentially results in a higher body burden of toxic chemicals (Rossignol et al. 2014). Investigating the contribution of environmental chemicals to autism offers an opportunity for intervention by reducing such exposures.
OK. Some environmental campaign group emails to say:
3 April 2019, Brussels – The existing scientific evidence of the links between the brain-harming pesticide chlorpyrifos and the development of autism among children should urgently be reviewed, according to a new study published today in Environmental Health Perspectives . This call, published a day after World Autism Day, adds to well-founded concerns about health effects of human exposure to chlorpyrifos, as the pesticide authorisation is currently being discussed for possible prolongation in Europe .
According to the World Health Organisation, reviews estimate that 1 child in 160 has an autism spectrum disorder. Some recent studies have, however, reported rates that are substantially higher . The study comes in a context of increases of autism and autism spectrum disorders over the past decades . For example in the US, the prevalence of autism has increased from 1 in 150 in 2002 to 1 in 59 in 2014 . These trends cannot be explained by genetics alone and are increasingly explored in the lens of environmental exposure.
Fine. We can’t just dismiss every such concern out of hand. Mercury in seafood really was a problem in Minimata. We must, at least, run a quick test on this.
Chlorpyrifos (CPS) is an organophosphate pesticide used on crops, animals, and buildings, and in other settings, to kill a number of pests, including insects and worms. It acts on the nervous systems of insects by inhibiting the acetylcholinesterase enzyme. Chlorpyrifos was introduced in 1965 by Dow Chemical Company. Chlorpyrifos is considered moderately hazardous to humans by the World Health Organization based on its acute toxicity. Exposure surpassing recommended levels has been linked to neurological effects, persistent developmental disorders, and autoimmune disorders. Exposure during pregnancy may harm the mental development of children, and most home uses of chlorpyrifos were banned in the U.S. in 2001. In agriculture, it is “one of the most widely used organophosphate insecticides” in the United States, and before being phased out for residential use was one of the most used residential insecticides.
OK, so we’ve done out test on the thesis, it’s colei and they can bugger off then.
The reason being that we’ve a massive discontinuity in exposure there. The half life of chlorpyrifos is some 60 days, anything other than the most minuscule trace will be gone in a year. Before 2001 it was often used around domestic environments, in them. Afterwards, in the US at least, it wasn’t. Direct exposure levels to human infants – the subject under discussion, or pregnant mothers perhaps – is thus wildly different between US pre-2001 and post, and between the US post- 2001 and those places where it is still use in those domestic environments.
If there was any connection between autism and chlorpyrifos usage then we’d see a significant decrease in autism incidence post-2001 in the US. We don’t. Or not that anyone has noted. This paper and this environmental group actually arguing the opposite, that lower chlorpyrifos exposure in that domestic environment is coincident with a higher autism rate.
It’s as if a halving of the smoking rate leads to a doubling in lung cancer incidence.
At which point we can happily conclude that this is all those colei and we can go off and ponder something more interesting, like why Simon Cowell? Even, pausing to give these campaigners a good kick on the logics as we do so.