(NaturalNews) Evidence supporting the notion that environmental toxins might play a role in triggering autism, especially in young boys, has made its way into the open-access journal PLOS Computational Biology. Researchers from the University of Chicago (UoC) found that, based on an analysis covering more than 100 million U.S. medical records, a strong correlation exists between chemical-induced genital malformations in boys and significantly higher rates of autism.
The county-by-county investigation covered the entire U.S. and revealed that, for every 1 percent increase in frequency of genital malformations in a particular county, there is also a corresponding 283 percent increase in autism rates. Similarly, a 94 percent increase in intellectual disability (ID) rates was also observed for every 1 percent increase in genital malformations, particularly among boys.
"Autism appears to be strongly correlated with rate of congenital malformations of the genitals in males across the country," stated Andrey Rzhetsky, Ph.D., a professor of genetic medicine and human genetics at UoC and lead author of the new study. "This gives an indicator of environmental load and the effect is surprisingly strong."
Parental exposure to toxins increases autism risk
Seeking to better understand the relationship between environmental exposures and both cognitive and neurological function, Rzhetsky and his team decided to take a closer look at autism rates in conjunction with genital malformations. Using an insurance claims data set that covers nearly one-third of the total U.S. population, the team constructed several graphs mapping the data in order to make comparisons.
After creating a statistical baseline frequency of autism and ID that covers every county throughout the nation, Rzhetsky and his team compared rates of these disorders to rates of genital malformations in order to make their calculations. They also factored in outside influences like ethnicity, age, socioeconomic status and geopolitical ranking, all of which may unduly influence the outcomes.
In the end, the team observed sharp increases in both ID and autism in conjunction with genital malformations, which have repeatedly been linked to parental exposure to environmental toxins. Recognizing that unborn males are particularly sensitive to these toxins, which include things like lead and pharmaceuticals, the team arrived at some not-so-pleasant conclusions.
"We interpret the results of this study as a strong environmental signal," Rzhetsky is quoted as saying.
Environment plays significant role in autism rates, affirms California study
A study from the University of California, Davis, (UCD) that was published back in 2009 seems to affirm these findings, having found that environmental exposure to chemicals in household cleaning products, pesticides and other sources may be responsible for a corresponding rise in autism rates.
As published in the peer-reviewed journal Epidemiology, the UCD study covered 17 years' worth of state data on developmental disability rates, as well as birth records collected from the U.S. Census Bureau on autism rates and ages of diagnosis. Upon review, the team involved was unable to discount environmental factors like pesticides as major contributing factors in ever-increasing rates of autism.
"It's time to start looking for the environmental culprits responsible for the remarkable increase in the rate of autism," stated Irva Hertz-Picciotto, lead author of the study and professor of epidemiology at UCD. "There's genetics and there's environment. And genetics don't change in such short periods of time."
Affirming this position, Dr. Bernard Weiss from the University of Rochester Medical Center told Environmental Health News that too much emphasis has been placed on genetics in autism. Advances in molecular genetics, he says, invalidate the widespread assumption that "faulty genes" alone are the primary drivers of autism.