More than 40 years ago, people in Michigan were poisoned. Researchers are still following those people today.
In 1973, a fire-retardant chemical called PBB, polybrominated biphenyl, accidentally got mixed into livestock feed. It took a year to discover the accident.
Studies estimate 70-90% of people in Michigan had some exposure to PBB from eating contaminated milk, meat and eggs. The MDCH says the "overwhelming majority of those who were exposed to PBB received very low levels."
Other people had higher levels of exposure.
Researchers at Emory University in Atlanta are studying the long-term health effects of exposure to PBB. The team was in Michigan this past weekend to continue the study.