"The Environment as an etiologic factor in autism: a new direction for research"  by EA London was published online by ehp, Environmental Health Perspectives, in 2000. Today, 12 years later, it remains the direction not taken as "autism research" continues down the road of genetic obsession and largely ignores environmental autism research.

Although public health authorities have paid lip service to the idea that autism appears to result from gene environment interaction funding has been overwhelmingly directed towards the gene side of the equation. The people who are much smarter than most of us, who understand things we can not possibly understand, who do not need our input as unwashed, unthinking parents of autistic children simply keep on keepin' on with their religious like belief that autism is primarily genetic.  Following is the abstract and the suggestion for new lines of investigation into environmental exposures which the US IACC, the Canadian Institutes for Health Research and other agencies involved with setting directions for autism research do not appear to have accepted. Of course the genetic obsession research has brought us a better understanding of autism causes .... hasn't it?

If you have a child who is severely affected by an autism disorder, whose ability to understand the world is limited, who wanders into dangerous traffic, lakes or rivers,  is prone to seizures or  engages in serious self injurious behavior autism is not just an alternative way of thinking or an opportunity to build a career mouthing empty feel good cliches about autism acceptance on twitter.  If you are a parent with a severely autistic child you will probably fight for evidence based autism interventions, accommodation in the schools for autistic students and a place for them to live with dignity as you grow old and ultimately die.  These are the harsh realities faced by  parents with low functioning autistic children who must look at autism seriously and not as an opportunity to tell the world that everything problematic about autism is solved if we all just accept autism in our child. For many parents we would like to see solid scientific research into all the causes and conditions that create autism in our children, genetic and environmental causes.

Autism may be prevented, treated or even cured in the future if the research is done.  If that research leads us to the age of the father in some cases then that is important to know. If that research leads us into the multitude of possible impacts on children while in the incredibly important environment known as the womb then that research must be done.  What will not help in understanding autism is simply throwing our hands up in the air and arguing that we should not conduct research on the prenatal environment or in mocking attempts to research possible environmental causes of autism as some Neurodiversity bloggers like to do.  

For many of us our child's Autistic Disorder is a serious, life impairing disorder, and a mystery  that must be solved by solid research, genetic and environmental. Environmental research has been short changed and a solid environmental research strategy is required as recently advocated by Philip Landrigan and his colleagues in A Research Strategy to Discover the Environmental Causes of Autism and Neurodevelopmental Disabilities. Landrigan and his colleagues Luca Lambertini and Linda Birnbaum of the Children’s Environmental Health Center, Mount Sinai School of Medicine, New York and NIEHS and NTP, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina.  

The distinguished authors argument includes a "proof of principle" segment in which they list studies linking various toxic substances to neurodevelopmental impairments:

"Exploration of the environmental causes of autism and other NDDs has been catalyzed by growing recognition of the exquisite sensitivity of the developing human brain to toxic chemicals (Grandjean and Landrigan 2006). This susceptibility is greatest during unique “windows of vulnerability” that open only in embryonic and fetal life and have no later counterpart (Miodovnik 2011). “Proof of the principle” that early exposures can cause autism comes from studies linking ASD to medications taken in the first trimester of pregnancy—thalidomide, misoprostol, and valproic acid—and to first trimester rubella infection (Arndt et al. 2005; Daniels 2006).

Landrigan, Lambertini and Birnabaum generated a list of 10 chemicals that they recommended as priorities for investigation.  They expressly stated that the list is not intended to be exhaustive but is intended to provide a strategic environmental research focus to catalyze new evidence based programs for prevention of neurodevelopmental disorders in children. The  list includes some very well known dangerous substances:

1. Lead (Jusko et al. 2008)
2. Methylmercury (Oken et al. 2008)
3. Polychlorinated biphenyls (Winneke 2011)
4. Organophosphate pesticides (Eskenazi et al. 2007; London et al. 2012)
5. Organochlorine pesticides (Eskenazi et al. 2008)
6. Endocrine disruptors (Braun et al. 2011; Miodovnik et al. 2011)
7. Automotive exhaust (Volk et al. 2011)
8. Polycyclic aromatic hydrocarbons (Perera et al. 2009)
9. Brominated flame retardants (Herbstman et al. 2010)
10. Perfluorinated compounds (Stein and Savitz 2011).
    
    

Landrigan, Lambertini and Birnbaum recognize the importance of genetic research but, as other learned authorities have noted, genetic research has received the overwhelming share of autism research dollars. The recent IMFAR conference in Toronto left me with the impression that the "it's gotta be genetic" trend of channeling autism research overwhelmingly toward genetic research  is continuing. As these learned authors have argued so compellingly it is critically important that environmental autism research be focused .... and funded ... if autism disorders are to be prevented, treated or cured in future.

In A Research Strategy to Discover the Environmental Causes of Autism and Neurodevelopmental Disabilities, an editorial in the current issue of Environmental Health Perspectives, authors Philip J. Landrigan, Luca Lambertini and Linda S. Birnbaum make a  compelling argument for strategically researching environmental causes of autism and neurodevelopmental disabilities. In the process they provide an understanding of autism as a family of disorders.   The authors point out that, despite the attention paid to genetic causes of autism disorders,  a large number of genes have been identified as candidates in causing autism disorders with no single dominant genetic anomaly and with no disorders attributable to 60-70% of autism disorders: 

Landrigan, Labertini and Birnbaum summarize the evidence for the "proof of principle" that early exposures during “windows of vulnerability” that open only in embryonic and fetal life and have no later counterpart can cause autism.  They review the large numbers of synthetic chemicals, many of them untested, some of which are known to have toxic properties. The authors propose a strategic approach to researching possible environmental causes of autism by focusing:

"research in environmental causation of NDDs on a short list of chemicals where concentrated study has high potential to generate actionable findings in the near future. Its ultimate purpose is to catalyze new evidence-based programs for prevention of disease in America’s children."

The authors recognize that the list of 10 possible environmental causes deserving of focused research at this time would expand with time and scientific developments.  As a start though they propose based on the studies referenced following the substance: Lead (Jusko et al. 2008) Methylmercury (Oken et al. 2008) Polychlorinated biphenyls (Winneke 2011) Organophosphate pesticides (Eskenazi et al. 2007; London et al. 2012) Organochlorine pesticides (Eskenazi et al. 2008) Endocrine disruptors (Braun et al. 2011; Miodovnik et al. 2011) Automotive exhaust (Volk et al. 2011) Polycyclic aromatic hydrocarbons (Perera et al. 2009) Brominated flame retardants (Herbstman et al. 2010) Perfluorinated compounds (Stein and Savitz 2011).

The strategic approach to environmental autism research is an idea who time has come.  In fact it is long overdue. The respected authors of the EHP editorial will undoubtedly be vilified by the usual suspects, Neurodiversity ideologues and industrial and pharmaceutical spin doctors employed to cast doubt on the need for any environmentally focused autism research.  However, given the support of the NIEHS and Autism Speaks, there is substantial reason to hope that the strategic focused study of environmental causes of autism and other neurodevelopmental disorders is underway.

It's about time.