BOULDER, Colo. – The incidence of autism spectrum disorder, ASD, has rapidly increased over the last several decades, and some environmental factors are being blamed as the driving force behind the diagnosis.
First described in the 1930s as a novel clinical disorder, today one in 68 children in the United States, including 1 in every 43 boys, are diagnosed with ASD. This is in contrast with 1 in 2,500 boys in the early 1970s.
The study was published online in the September issue of Environmental Health, and examines some of the toxins that may contribute to the growth in ASD diagnosis.
Author Cynthia D. Nevison, Ph.D., of the Institute of Arctic and Alpine Research at the University of Colorado, used trend data from birth years 1970 to 2005 from the combination of the California Department of Developmental Services and the United States Individuals with Disabilities Education Act and temporal trends in suspected toxins listed during an extensive literature survey.
Results are showing that up to 80 percent of the increased incidence of autism since 1988 is due to an actual increase in the disorder.
While some of the environmental toxins suspected in the contribution to ADS have shown flat or decreasing temporal trends that correlate poorly to the rise in ADS (these include lead, organochlorine pesticides and vehicular emissions), toxins such as polybrominated diphenyl ethers, aluminum adjuvants, and the herbicide glyphosate have increasing trends that correlate positively to the rise in autism.
Nevison suggests further studies be conducted on environmental factors with increasing temporal trends in order to learn more about what is driving the increase in ADS.