The role of vaccines in causing Autism has led to much discussion among scientists the community of people with disabilities.
Are there environmental pollutants which can cause developmental disabilities, where the delays present around age three, as is the case for Autism?
Pollutants
Researchers at Columbia University have found multiple pollutants which may cause developmental delays in the toddler/pre-school years. One such pollutant is Chlorpyrifos.
Pesticide
Chlorpyrifos, trade name Dursban (by Dow Chemical) has been used as a pesticide, used widely indoors to control cockroaches.
Neural Development Affected
The toxin can lead to birth defects in the following areas of the brain: the ventricles, corpus callosum, choroid plexus, and septum pellucidum. Deficient growth in any of these areas may cause learning disabilities and psychiatric problems.
Of the children exposed to Chlorpyrifos tested by JD Sherman at WesternMichiganUniversity, all demonstrated growth retardation, and three of the four manifested profound mental retardation and low muscle tone. A similar pattern of development and birth defects has been discovered in test animals.
EPA’s Action
The United States Environmental Protection Agency (EPA) banned the sale of Chlorpyrifos for residential and indoor uses in 2000, effective December 31, 2001.
(Dow continues to produce and market Dursban in India for domestic use, claiming that it is safe for humans).
Results of Chlorpyrifos Exposure
Children aged three with high levels of Chlorpyrifos exposure scored on average nearly seven points lower on tests of Bayley Psychomotor development, and scored three points lower on the Bayley Mental Development Index. To put this in perspective, children with these patterns of scores were five times more likely to experience developmental delays.
Potential for Difficulties
Exposed children were more likely to manifest developmental delays, which include pervasive developmental disorders (PDD) on the Autism Spectrum; the children were also more likely to demonstrate attention problems.
Conclusion
Children exposed to Chlorpyrifos are significantly at greater risk of needing special education, and may exhibit attention problems, learning disabilities, developmental disabilities, and psychiatric problems.
Sources:
Rauh, V. A., Garfinkel, R., Perera, F. P., Andrews, H. F., Hoepner, L., Barr, D. B., Whitehead, R., Tang, D., & Whyatt, R. W. (2006). Impact of Prenatal Chlorpyrifos Exposure on Neurodevelopment in the First 3 Years of Life Among Inner-City Children. Pediatrics, 118(6), e1845-59.
Sherman, J. (1996). Chlorpyrifos (Dursban) - associated birth defects: report of four cases. Arch Environ Health, 51(1), 5-8.
Additional Research provided by Scott L. Donaldson, Ph.D.
