[ti:US Study Links Air Pollution to Autism] [ar:Anna Matteo] [al:Health and Lifestyle Report] [by:www.51voa.com] [00:00.00]From VOA Learning English, this is the Health & Lifestyle Report. [00:06.07]Autism spectrum disorder is a developmental disability. [00:11.69]People with autism have trouble communicating [00:15.47]and with social skills. [00:17.80]The U.S. Centers for Disease Control and Prevention says [00:21.83]the person also might repeat some behaviors [00:26.28]and not want change in their daily activities. [00:30.12]Some people with the condition need a lot of help. [00:34.59]Others need less. [00:36.75]CDC officials say autism affects one [00:41.47]in every 68 children in the United States. [00:45.20]More boys than girls are believed to have the condition. [00:49.89]But the number of cases appears to be growing. [00:54.24]It is unclear whether the growing number [00:58.37]shows a real increase [01:00.29]or comes from more knowledge about this disorder. [01:04.73]Common signs of autism include trouble making eye contact [01:11.00]and a delay in learning how to speak. [01:14.38]Some people with severe autism never learn how to talk. [01:19.87]Many people with autism [01:22.85]also have difficulty understanding facial expressions [01:28.29]and the feelings of others. [01:30.47]They also have trouble making friends of the same age. [01:35.72]Doctors have learned how to recognize autism, [01:40.31]but much is still unknown about its causes. [01:44.86]Researchers at Harvard University [01:48.21]have come closer to finding answers. [01:51.22]They found that women exposed to the highest levels [01:55.99]of fine particulate air pollution late in their pregnancies [02:00.54]are two times more likely to give birth to a child with autism. [02:07.75]The findings appeared in Environmental Health Perspectives -- [02:11.57]a publication of the National Institute [02:14.44]of Environmental Health Sciences. [02:18.15]Marc Weisskopf led the Harvard researchers. [02:21.14]Mr. Weisskopf studies environmental conditions [02:24.61]that cause sickness, developmental disabilities and deaths. [02:30.26]He and his team studied women [02:32.86]who were late in their pregnancies, [02:35.32]shortly before they gave birth. [02:37.49]In all, they examined medical records [02:40.97]from all 50 U.S. states for about 116,000 mothers and their children. [02:48.48]The study found that the women [02:51.32]who were around high levels of fine particulate matter air pollution [02:55.84]were at highest risk of having an autistic child. [03:00.39]The increased risk of these women was two times [03:04.53]that of women who lived in areas with low levels [03:08.27]of fine particulate pollution. [03:10.34]The researchers found that the timing of exposure [03:14.08]to pollution was important. [03:16.94]They found no increased risk of autism in children [03:21.85]whose mothers were around high levels [03:24.42]of pollution before becoming pregnant. [03:27.52]And the study found air pollution does not seem to [03:32.85]increase the risk of children developing autism after they are born. [03:38.41]Marc Weisskopf says this finding does not prove [03:42.54]there is a direct link between pollution and autism. [03:46.63]But, he adds, it has ratcheted up, or increased, [03:51.24]his team's confidence that there is a relationship between the two. [03:55.92]"Finding an association like this [03:59.05]that's very specific in time rules [04:00.95]out a lot of other possible explanations for that. [04:04.13]So, it really ratchets up the strength of our confidence [04:07.78]that we've got something really related to the air pollution here." [04:11.91]Mr. Weisskopf says pregnant women [04:14.68]should avoid air pollution as much as possible. [04:17.89]But he warns that other things [04:20.23]may increase the risk of autism spectrum disorder. [04:24.52]"You can avoid being in extremely polluted cities [04:28.28]during pregnancy if possible. [04:30.96]You can also choose to go running in a park [04:33.34]rather than next to a street. [04:34.54]But that said, I think also it's very important to recognize [04:38.17]that autism spectrum disorders is a very multi-factorial disorder. [04:42.70]And there are lots of reasons why risk could be increased." [04:45.81]Autism is believed to result [04:48.00]from a combination of environmental and genetic factors. [04:51.92]Autism Speaks is an organization [04:55.77]that helps families with autistic children. [04:58.77]Paul Wang is head of medical research at Autism Speaks. [05:03.36]He says the findings are very compelling. [05:06.44]He notes that during the last three months of pregnancy, [05:10.66]the brain of the fetus develops very quickly. [05:14.58]He says the study does not change his group's main suggestion: [05:19.47]focus on treatment and educational therapies. [05:23.29]"For parents of children who have already been diagnosed, [05:26.58]the focus should continue to be on treatment for them, [05:30.03]on the behavioral, educational therapies that are available [05:34.76]and that we know can help kids who are diagnosed with autism." [05:38.71]For now, Marc Weisskopf says researchers [05:41.98]are trying to identify the exact substances in air pollution [05:46.81]that increase the risk of autism. [05:49.75]And that's the Health and Lifestyle Report from VOA Learning English. [05:54.83]I'm Anna Matteo. [05:56.40]¸ü¶àÌýÁ¦Çë·ÃÎÊ51voa.com