The more Ozone and Particulate Matter pollution a baby in the womb is exposed to, the more likely he or she will be born with autism according to a new UCLA study published March 1st in Environmental Health Perspectives, a peer-reviewed journal published by the National Institute of Environmental Health Sciences. It's the largest study of its kind to date and is the first to link autism with ozone, or smog, levels.
Researchers compared levels of air pollutants, mostly related to vehicle traffic, during pregnancy gestation periods of 7,603 children with autism and 75,635 children without autism, born from 1995 to 2006 in Los Angeles. Babies at the 75th percentile of exposure to toxins had a 8 percent to 10 percent higher risk of autism than babies at the bottom 25th percentile, the study said. Ozone and fine particulates had the strongest association with autism.
Using government air monitoring stations, researchers estimated average exposures during pregnancy to carbon monoxide, nitrogen dioxide, nitric oxide, ozone and particulate matter. The study adjusted for factors that include maternal age, birthplace, race and education. Using birth certificates, researchers compared control children with non-control children who had matching birth year, sex and gestational age at birth.
"These findings are of concern, since traffic-related air pollution is ubiquitous," said Dr. Beate Ritz, chair of UCLA's Department of Epidemiology and the study's senior author. She said she was reluctant to advise expectant mothers to leave LA or polluted cities, because that's not an option for many. "We can't tell them to not breathe or not go outside or not go to work," she said. She did recommend avoiding sitting in traffic, when pollutant exposure is worst."
Autism is a spectrum of disorders ranging from a profound inability to communicate and mental retardation to milder symptoms seen in Asperger's syndrome. The Centers for Disease Control and Prevention estimates that autism affects one in every 88 children born in the U.S., a 25 percent increase from 2006.
A study in 2010 was the first to look at autism and toxins specifically from auto exhaust. The study, based in California, reported that children born to mothers living within 9/10 mile of a freeway during pregnancy were more likely to be diagnosed with autism than children whose mothers lived more than 1/4 mile from a freeway. However, the sample size — 304 autism cases and 259 controls — was much smaller than the just-published UCLA study.
Most policy discussions concerning air pollution in DFW surround the damage done to lungs, or maybe hearts and lungs. Rarely are the other, now well-known associations between air pollution and birth defects, or air pollution and brain function mentioned. And even rarer is the fact mentioned that these harms are often occurring at levels of pollution considered to be officially "safe" or at least legal. We really have no idea what the assault on our bodies by chemicals we involuntarily breathe actually can do to our health over the long term. That's why we should minimize exposure to them as much as possible. And that means limiting the chemicals' movements, not those of expectant moms.
Along with a higher risk of asthma, children who are born and live their first year closer to major freeways also suffer a significantly elevated risk of autism. That's the conclusion of a new study by the Keck School of Medicine of the University of Southern California in Los Angeles.
"Compared to 245 California children who were not autistic, the researchers found that 279 autistic children were almost twice as likely to have been exposed to the highest levels of pollution while in the womb, and about three times as likely to have been exposed to that level during their first year of life.
They found that children exposed to the highest amount of "particulate matter' – a mixture of acids, metals, soil and dust – had about a two-fold increase in autism risk. That type of regional pollution is tracked by the Environmental Protection Agency.
Volk and her colleagues also saw a similar link between autism and nitrogen dioxide, which is in car, truck and other vehicle emissions.
'This is a risk factor that we can modify and potentially reduce the risk for autism,' wrote Dawson in an email to Reuters Health."
It's been estimated by the Centers for Disease Control that autism affects one in every 88 children born in the United States.
A new federal Particulate Matter standard is under consideration by the EPA and could be announced this year. It's been linked to other neurological diseases such as Parkinson's and Alzheimers.