Swedish Scientists Find Link Between Vinyl Flooring And Autism

A group of Swedish researchers were asking Swedish families about the physical components of their homes, in an attempt to study the correlation between indoor air pollutants and allergies. To their surprise, they stumbled across a correlation between autism and four home life indicators:

" Vinyl or PVC floors
" Smoking on the part of the mother
" Family economic problems
" Condensation on windows, indicating poor home ventilation

Out of the 4,779 children between the ages of 6 and 8 included in the survey, 72 had autism. Although the study was originally intended to focus on childhood allergies and asthma, the researchers realized they might be on to something.

The link between low income and asthma is fairly sturdy here in the United States, although studies have not previously correlated autism incidence with family income levels. Interestingly enough, a recent study did find that having an autistic child severely reduced a family's income, presumably because parents were forced to make choices like reducing their work hours in order to care for their child. "Family economic problems," therefore, can tentatively be ruled out on the basis of cause and effect. After all, the study covered families who already had autistic children.

The study found that children "were twice as likely to have autism if their mothers smoked cigarettes. The autistic children also were more likely to have asthma." I doubt anyone will contradict the toxicity of cigarettes, particularly when smoked by a pregnant woman. If the mother smoked inside, in a home with poor ventilation, that would greatly exacerbate the problem.

The most intriguing item on this list is the link between autism rates and vinyl or PVC flooring. Vinyl contains phthalates, the "it" toxin of the decade. Phthalates are added to plastic to make it more pliable, and are known to be highly toxic and carcinogenic. Phthalates are why you are advised not to microwave plastic containers, and why trendsetters and the environmentally aware are ditching their plastic water bottles for aluminum ones.

Phthalates have been shown to cause endocrine disruption and birth defects in rats, and the CDC has found that the majority of Americans have phthalate residue in their bloodstream. However, no one is sure at this point what the threshold level for phthalates is, or should be. Phthalates could be a red herring, or they could be equivalent to the lead which was once used for water pipes.

As with every other autism study, particularly one as relatively strong as this one, the scientists involved advocate caution. As we all know, correlation does not imply causation. Even the authors carefully add, ""The data are far from conclusive. They are puzzling, even baffling, and not readily explicable at this time." However, it does point in an intriguing new direction for researchers studying the possible causes of autism.

(I wonder what kind of flooring is most common in the homes of Somali immigrants in Minnesota? The New York Times recently published an interesting article about a cluster of autism among this particular micro-demographic.)