Health knowledge made personal
Join this community!
› Share page:
Go
Search posts:

Autism and the Antarctic Ozone Hole

Posted May 01 2012 12:00am

Antarc By Cynthia Nevison

“If ozone hole scientists had adopted the approach of many in the autism research community … (they) would have concluded that the ozone hole occurs because Antarctica is cold.”

A recent Associated Press report that 1 in 88 American children has an autism spectrum disorder (ASD) asserts that, “Better diagnosis is largely responsible for the new estimate…”  Another AP report, on a study finding that 1 in 38 South Korean children has an ASD, quotes the lead author as saying, “It doesn’t mean all of a sudden there are more new children with ASDs.  They’ve been there all along, but were not counted in previous prevalence studies.”  These are extraordinary claims and examples of autism epidemic denial.  Equally remarkable is that the AP presents them as unquestioned truth, making no effort to counter them with dissenting viewpoints.  In contrast, the media has been diligent about “balancing” articles on the threat of climate change with opposing views from “climate skeptics,” which has contributed to climate change denial.

Autism epidemic denial and climate change denial share some interesting similarities and differences, which are beyond the scope of this essay.  Here, I will focus on describing how some useful lessons might be learned by recalling one of the true success stories of atmospheric and environmental science: the discovery of the Antarctic ozone hole, the identification of its cause, and the quick action taken to address the problem.

A brief history of the Antarctic ozone hole:  A hole in the stratospheric ozone layer first occurred in the early 1980s and has recurred every year since during Antarctic springtime.   The hole is caused by manmade chlorofluorocarbons (CFCs) and other halocarbons, which deliver chlorine and bromine atoms to the stratosphere.  These atoms are normally stored in inactive compounds, but are liberated in the presence of sunlight by reactions on the surface of polar stratospheric clouds (PSCs) to highly reactive, ozone-destroying species.  PSCs are composed of frozen water and acids and can only form at extremely cold temperatures, such as those that occur during Antarctic spring.  While scientists initially doubted the existence of the ozone hole, they identified and largely proved its cause by the late 1980s.  The hole provided urgency and renewed impetus for the Montreal Protocol and its amendments, which banned the CFCs.   (International negotiations were already underway due to concerns over milder gas-phase ozone loss.)  Following the ban, CFCs are declining in the atmosphere, albeit only slowly due to their long atmospheric lifetimes.  Stratospheric chlorine and bromine are expected to return to safer pre-1980 levels by the middle to late part of this century, at which point the ozone hole will close.  

The relevant point is this: while one can say with some accuracy that the ozone hole occurs because Antarctica is cold, the pre-1980s ozone layer over the continent was perfectly adequate at blocking harmful UV radiation.  It was only with the accumulation of CFCs in the atmosphere, reaching dangerous levels by the 1980s, that the extreme cold over Antarctica became a threat to ozone. By distinguishing between the actual trigger for the ozone hole (CFC production and release to the atmosphere), which are within human control, and the predisposing factors (naturally cold temperatures), which are not, the international community was able to identify the cause of the problem and take decisive steps to end it.

These are lessons that the autism research community might do well to heed.  In the year that I have been following the scientific literature on autism as a SafeMinds volunteer, I’ve observed that the distinction between predisposing factors and actual causes often is not made.  In addition, crucial information is not recalled.  Namely, CDC autism statistics are cut off at birth year 1992, even though independent research shows that the onset of the surge in U.S. autism occurred around birth year 1988.   Prior to that time, the available and often forgotten data show that autism prevalence was at most 1 in 2,500.  With this lack of historical perspective, the complacent explanation of “better diagnosis” appears more plausible and the urgency to address the problem recedes.

If atmospheric scientists had adopted the approach of many in the autism research community, Antarctic ozone column measurements prior to the 1980s would have been forgotten, leading the scientists to declare that the ozone hole had “been there all along.” Obvious clues, such as the elevated levels of reactive chlorine measured in the hole, would have been dismissed as pure coincidence.  Believing the springtime hole to be a natural and unpreventable phenomenon, the scientists would have focused their efforts on early detection, enabling them to warn visitors to Antarctica to use sun protection.  Statistical correlations between temperature and ozone would have led the scientists to note that cold temperatures increased the odds ratio of having an ozone hole. In short, the scientists would have concluded that the ozone hole occurs because Antarctica is cold.  Meanwhile, the hole would have continued to worsen year by year, as human CFC release to the atmosphere continued unchecked. 

Parents are keen and devoted observers of their young children’s development.  It is obvious to some parents that their child’s regression into autism occurred after receiving a battery of vaccines. That said, the large increase in the number of vaccines given to young children, including newborns, which began in the late 1980s and continues today, is unlikely to be the only factor involved in the autism epidemic.  If it were, one would expect epidemiology to give a clearer result.  But over-vaccination is certainly a trigger in at least some cases, as the government itself has quietly admitted.  This, combined with the oxidative stress and immune system dysfunction that are well documented in autistic children, would seem to provide valuable clues to guide the search for causation.  However, the public health establishment has largely discounted the eyewitness testimonies of parents and the supporting biological research.  Instead, it has exalted the results from blind statistical correlations (i.e., the epidemiological studies that in most, but not all, cases find no link between vaccines and ASD prevalence) above all other forms of evidence and focused on largely fruitless genetic investigations. 

Parents are understandably angry when the establishment appears to blame them, their genes, their age and, most recently, their fat cells for their children’s autism.  Again, the distinction is not made between predisposing risk factors and actual causes.  Pertinent questions such as, was there a dramatic increase in maternal obesity in 1988?, are not asked, even as absurd pronouncements that 1 to 3 percent of children have always been autistic go unchallenged in the popular press. 

The Antarctic ozone hole story is on course for a happy ending.  Our children can look forward to seeing the springtime hole diminish and finally close once and for all in their lifetime.  If the public health and autism research community were to stop ignoring inconvenient truths and to focus more on causal agents that can be controlled rather than predisposing vulnerabilities that can’t, it is possible that our children could enjoy a similar decrease of autism to pre-1980s levels or better.

Cynthia Nevison is an atmospheric research scientist at the University of Colorado, Boulder who has worked on stratospheric ozone and greenhouse gas issues.  She is a volunteer researcher for SafeMinds and a member of their Environmental Committee.

 

Posted by Age of Autism at May 03, 2012 at 5:45 AM Permalink

Post a comment
Write a comment:

Related Searches