Young students often most vulnerable to toxic air - associations with autism

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Abstracts about airborne pollutants and autism-rates follow the news item.

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*Young students often most vulnerable to toxic air*

By Blake on, Brad Heath, Rick Jervis USA Today Dec 22, 2008

http://www.usatoday.com/news/nation/environment/2008-12-21-youngkids_N.htm

>From the front door of the aged brick school, the 4-year-olds at

Wyandotte Early Childhood Center in Baton Rouge can spot the cottony

plumes from the ExxonMobil plant, the nation's second-largest refinery.

The circumstances at Wyandotte mirror those at thousands of other

schools across the nation, including many schools that house the

youngest --- and most vulnerable --- kids.

Based on the levels and potential health hazards of the chemicals likely

to be outside, a model used by USA Today ranked Wyandotte among the

worst 1% of schools in the nation --- and the worst in Louisiana.

more...

<http://www.usatoday.com/news/nation/environment/2008-12-21-youngkids_N.htm>

- - - - Each of the following is free online:

1. *Autism spectrum disorders in relation to distribution of hazardous

air pollutants in the san francisco bay area*

Windham GC et al.

Environ Health Perspect. 2006 Sep;114(9):1438-44.

http://www.ehponline.org/members/2006/9120/9120.html

OBJECTIVE: To explore possible associations between autism spectrum

disorders (ASD) and environmental exposures, we linked the California

autism surveillance system to estimated hazardous air pollutant (HAP)

concentrations compiled by the U.S. Environmental Protection Agency.

METHODS: Subjects included 284 children with ASD and 657 controls, born

in 1994 in the San Francisco Bay area. We assigned exposure level by

census tract of birth residence for 19 chemicals we identified as

potential neurotoxicants, developmental toxicants, and/or endocrine

disruptors from the 1996 HAPs database. Because concentrations of many

of these were highly correlated, we combined the chemicals into

mechanistic and structural groups, calculating summary index scores. We

calculated ASD risk in the upper quartiles of these group scores or

individual chemical concentrations compared with below the median,

adjusting for demographic factors.

RESULTS: The adjusted odds ratios (AORs) were elevated by 50% in the top

quartile of chlorinated solvents and heavy metals [95% confidence

intervals (CIs) , 1.1-2.1], but not for aromatic solvents. Adjusting for

these three groups simultaneously led to decreased risks for the

solvents and increased risk for metals (AORs for metals: fourth quartile

= 1.7 ; 95% CI, 1.0-3.0 ; third quartile = 1.95 ; 95% CI, 1.2-3.1) . The

individual compounds that contributed most to these associations

included mercury, cadmium, nickel, trichloroethylene, and vinyl chloride.

CONCLUSIONS: Our results suggest a potential association between autism

and estimated metal concentrations, and possibly solvents, in ambient

air around the birth residence, requiring confirmation and more refined

exposure assessment in future studies.

PMID: 16966102

2: *Proximity to point sources of environmental mercury release as a

predictor of autism prevalence*

Palmer RF, Blanchard S, Wood R.

Health Place. 2009 Mar;15(1):18-24. Epub 2008 Feb 12.

http://tinyurl.com/78kmu9

The objective of this study was to determine if proximity to sources of

mercury pollution in 1998 were related to autism prevalence in 2002.

Autism count data from the Texas Educational Agency and environmental

mercury release data from the Environmental Protection Agency were used.

We found that for every 1000 pounds of industrial release, there was a

corresponding 2.6% increase in autism rates (p<.05) and a 3.7% increase

associated with power plant emissions(P<.05). Distances to these sources

were independent predictors after adjustment for relevant covariates.

For every 10 miles from industrial or power plant sources, there was an

associated decreased autism Incident Risk of 2.0% and 1.4%, respectively

(p<.05). While design limitations preclude interpretation of individual

risk, further investigations of environmental risks to child development

issues are warranted.

PMID: 18353703

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