The latest statistics on autism prevalence are scary: according to the Centers for Disease Control and Prevention, the disorder now affects, with varying degrees of severity, one in 88 children, and one in 54 boys. That represents an estimated 78 percent increase since 2002, the government agency reported last week. The CDC was quick to downplay the most dramatic possible interpretations of these findings, even as Mark Roithmayr, president of the advocacy group Autism Speaks, rushed to label them evidence of “a national emergency in need of a national plan.”

“There is the possibility that the increase in cases is entirely the result of better detection,” CDC director Thomas Frieden cautioned, speaking on behalf of a research community profoundly spooked by the anti-vaccine hysteria that has accompanied talk of an autism “epidemic” in the past.

(MORE: Autism: One in 88 Children Diagnosed, But Is The Increase for Real?)

Statements from the National Institute of Mental Health director Thomas Insel this week, however, suggest that the research community’s support of the idea that most or all of the vast reported increase in autism can be attributed to more awareness, or better testing, easier access to special programs and public school services, or “diagnostic substitution” (the recognition that kids who in the past were labeled mentally retarded, or even schizophrenic, are actually autistic) is now being sorely tested. While the more-and-better-detection case can still be made, he noted in a recent blog post, it also can’t be denied that there is good research to suggest that “a real increase is quite likely.”

That’s a really big statement, coming from a cautious, panic-averse, chief of a government-funded research institution. And, adding on this week, Insel furthermore made clear that something (or some combination of things) in our environment is almost certainly helping drive the increase.

That statement, however mildly phrased, in support of a renewed focus on the environment was paradoxically the most important take-away from the front-page-headline-making findings this week regarding the genetic origins of autism. A consortium of scientists has now agreed that having a greater number of rare, tiny, spontaneous mutations in the parts of genes that code for proteins greatly increases a child’s risk of developing autism, particularly if these glitches occur in pathways that directly affect brain development. They’ve managed to isolate at least one variable – increasing paternal age – that’s responsible for increasing the likelihood that these mutations will show up in a child’s DNA.

(MORE: Judith Warner: Autism’s Lone Wolf)

This means that researchers can now say, with more explanatory evidence than ever before, that there is an aspect of the way we live now that may be playing at least some role in the rise of the number of autistic kids in recent years: “parental age has, of course, increased in the past few decades,” as Insel put it. But what hasn’t yet been identified are the factors that actually trigger the genetic mutations in the first place or that provide the later conditions in which the glitches express themselves through the development of autism spectrum disorders.

Researchers are, not surprisingly, reluctant to rush to judgment about environmental causes of disease. They have good reason to be reticent, as outbreaks in the U.S. and the U.K. of measles, mumps and, most recently, whooping cough, in the wake of public panic over vaccines have made strikingly clear. It’s extremely difficult to conduct solid research into environmental causes, particularly since, in the case of autism, it’s now largely believed that whatever environmental toxins play a role in the development of the disorder in young children are encountered in-utero. Exhaustive research into environmental influences would mean tracking babies before they’re born and isolating specific factors affecting families living in ever-changing, multivariously contaminated, un-laboratory-controllable environments.

The complexity and logistical hurdles that will accompany such research efforts boggle the mind. Yet the question of environmental causes of autism – a subject of fascinated speculation for researchers and the object of some large-scale studies – must be more consistently and openly addressed. Without more information and explanations from our country’s top researchers, including those with government agencies, there will only be more public panic. And any number of charlatans will be ready and willing to put anxious parents’ minds at ease.

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