The Environmental Protection Agency says as many as one in 12 American women have enough mercury in their bodies to put a baby at risk. This means as many as 300,000 infants a year may be at an increased risk of in-utero mercury exposure.
What are the effects of mercury in your body? The Sierra Club was in Hollywood Wednesday to help women answer that.
Women filed into Hollywood's Primrose Organics Salon -- not for a free haircut, but for another free service: They're snipping their strands to test for mercury in their bodies.
"I'm always curious about mercury levels. I know that it's in our environment, it can be contaminated in our food sources," said participant Annie Phyo.
Stylists are cutting 30 strands of hair close to the scalp. The samples will be sent to a laboratory at the University of Georgia.
"We're hoping that this test will help highlight how coal's pollution affects people right here in L.A.," said Sierra Club spokesman David Graham-Caso.
The Sierra Club says even though the nearest coal power plants are in Utah and Arizona, pollution from them still affects California residents.
"Coal-fired power plants emit toxic clouds of pollution with a lot of different pollutants in there. That pollution then gets rained down in the rivers and streams, and ends up in our fish, ends up in the ecosystem, ends up on our dinner tables right here in Los Angeles," said Graham-Caso.
Women of childbearing age are the big concern, because mercury can be especially harmful during pregnancy.
"They're carrying a fetus and mercury is most toxic to anybody, is the fetus, the fetal brain, the fetal nervous system," said Dr. Antonio Zamorano, a family-medicine expert at Glendale Adventist Medical Center.
Zamorano often counsels pregnant women about which types of fish they should eat.
"We tell women to eat oily fish. What is oily fish? Oily fish is salmon, halibut, herring, catfish," said Zamorano.
Fish that tend to be higher in mercury include swordfish and king mackerel.
The Sierra Club is pushing all coal-fired facilities to convert to clean-energy plants.
While none of the women at the Primrose salon want a bad result, they hope this event will deliver a message.
"Why wait for those fish to become contaminated to the point of not being able to eat them?" said Lisa Boyle, one of the women to be tested.
Los Angeles receives nearly 40 percent of its electricity from coal-fired power.