DALLAS - Angry parents of autistic children met on the federal courthouse steps Wednesday in Dallas to protest coal plants they say pollute the air and endanger their children.

Dallas mom Jennifer Keefe is right in the middle of the fight. Her son, 5-year-old Kevin Keefe, has autism. Doctors say his symptoms are the byproducts of extremely high levels of mercury in his system and his body simply can't fight the levels.

That is the reason why Keefe and other parents of autistic children have petitioned the government to cut back on coal-sourced energy from plants they believe emit mercury into the air.

“When we know we've found a needle in a haystack, we need to remove it and be responsible for the information we have found,” said Mika Bradford, Keller.

A new study from the University of Texas found a direct link between mercury emissions and autism in Texas school children.

UT researcher Raymond Palmer said there is “significant statistical association between how close the schools are to the sources and amounts of autistic children they have."

The study shows the closer schools are to coal plants, the more incidents of autism. That number lessened every 10 miles further.

Critics say the study uses emission estimates and is flawed.

Texas has 18 coal-fired power plants. The closest to the Dallas-Fort Worth area is in Fairfield, which is 70 miles east of Dallas.

The state recently permitted five and is considering three more.

E-mail mjepson@wfaa.com