If it seems like most of the people you know with autism are 22 or younger, that's because most people diagnosed with autism were born after 1987. A recent US EPA study has found a distinct "changepoint" year - or spike - in autism in California and elsewhere and concludes that it would be "prudent to assume that at least some portion of this increase is real and results from environmental factors."
"In the Danish, California, and worldwide data sets, we found that an increase in autism disorder cumulative incidence began about (the birth cohort years) 1988-1989," wrote the authors Michael E. Mc Donald and John F. Paul, of the EPA's National Health and Environmental Effects Research Laboratory.
"Although the debate about the nature of increasing autism continues," they added, "the potential for this increase to be real and involve exogenous (external) environmental stressors exists."
But it was the distinct timing in the increase of autism - the birth of an epidemic, as many believe - that was most notable, and which "may help in screening for potential candidate environmental stressors."
"The calculated year was determined to be significant," the EPA scientists said. The rate of increase before 1988 "was significantly different" than the rate after that year (the "postchangepoint," in epidemiology parlance). In California, the rate spiked from 5.7-per-10,000 before the changepoint, to 20.8-per 10,000 in its wake, and the worldwide dataset showed a similar jump (from 6.0 to 24.2). In Denmark, the rise was even more dramatic, though total incidence was only a fraction of that in the US: from 0.6 to 6.6....
David Kirby is the author of the critically acclaimed Animal Factory: The Looming Threat of Industrial Pig, Dairy, and Poultry Farms to Humans and the Environment available now at Amazon. He is also the author of Evidence of Harm , a contributor to Huffington Post and a contributor to Age of Autism .
By David Kirby
If it seems like most of the people you know with autism are 22 or younger, that's because most people diagnosed with autism were born after 1987. A recent US EPA study has found a distinct "changepoint" year - or spike - in autism in California and elsewhere and concludes that it would be "prudent to assume that at least some portion of this increase is real and results from environmental factors."
"In the Danish, California, and worldwide data sets, we found that an increase in autism disorder cumulative incidence began about (the birth cohort years) 1988-1989," wrote the authors Michael E. Mc Donald and John F. Paul, of the EPA's National Health and Environmental Effects Research Laboratory.
"Although the debate about the nature of increasing autism continues," they added, "the potential for this increase to be real and involve exogenous (external) environmental stressors exists."
But it was the distinct timing in the increase of autism - the birth of an epidemic, as many believe - that was most notable, and which "may help in screening for potential candidate environmental stressors."
"The calculated year was determined to be significant," the EPA scientists said. The rate of increase before 1988 "was significantly different" than the rate after that year (the "postchangepoint," in epidemiology parlance). In California, the rate spiked from 5.7-per-10,000 before the changepoint, to 20.8-per 10,000 in its wake, and the worldwide dataset showed a similar jump (from 6.0 to 24.2). In Denmark, the rise was even more dramatic, though total incidence was only a fraction of that in the US: from 0.6 to 6.6....
Please read and comment at Huffington Post HERE .
David Kirby is the author of the critically acclaimed Animal Factory: The Looming Threat of Industrial Pig, Dairy, and Poultry Farms to Humans and the Environment available now at Amazon. He is also the author of Evidence of Harm , a contributor to Huffington Post and a contributor to Age of Autism .