Study links mercury emissions to increase in autism

By Reuters - March 18, 2005

Mercury released primarily from coal-fired power plants may be contributing to an increase in the number of cases of autism, a Texas researcher says.

A study published yesterday in the journal Health and Place found that autism, a developmental disorder marked by communication and social interaction problems, increased in Texas counties as mercury emissions rose, said Claudia Miller of the University of Texas Health Science Centre in San Antonio.

"The main finding is that for every thousand pounds [450 kilograms] of environmentally released mercury, we saw a 17 per cent increase in autism rates," she said.

About 48 tonnes of mercury are released into the air annually in the United States from hundreds of coal-burning plants.

The study looked at Texas county-by-county levels of mercury emissions recorded by the Government and compared them with the rates of autism and special education services in 1200 Texas school districts.

"The study shows that there may be a very important connection between environmental exposure to mercury and the development of autism," Dr Miller said.

The US Centres for Disease Control has said it does not know how many cases of autism there are in the country or whether the number has increased, but that the issue is under study.

Some experts estimate there are 1.5 million people in the US with autism, most of them children, and say the number of cases has risen rapidly in recent years.

The Bush Administration this week ordered power plants to halve mercury pollution within 15 years, but environmentalists said a 90 per cent cut was needed.

"This research has implications for toxic substance regulation and prevention policies," said Raymond Palmer, an autism expert in San Antonio.

"Policies regarding toxic release of mercury and the incidence of developmental disorders should be investigated."