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.
A multi-generational study
Michele Marcus is a professor of epidemiology, environmental health and pediatrics at Emory University Schools of Public Health and Medicine, and she's the lead scientist on the research team. She's interested in studying how the exposure has affected the children and grandchildren of people who ate contaminated food.
"We are particularly focusing on people who were exposed in early childhood or perhaps while they were in the womb," she says.
The Emory researchers have been studying the PBB contamination of Michiganders for more than 15 years. Marcus says their research has shown that the chemical had effects on the endocrine systems of people who were exposed to it during "critical periods of development," such as in the womb or early childhood.
"So we found among the daughters of women with high exposure that they experienced their first menstrual period a full year earlier than girls who were not exposed. And now that they are adults, they do have a very high risk of miscarriages. And the boys who were exposed in the womb have reported more urinary and genital problems and slower growth and pubertal development," she explains.
Marcus's team is studying the third generation — the adult grandchildren of people who consumed the tainted animal products.
"We are seeing health effects, particularly reproductive health effects like the miscarriages. And we know from animal studies that in fact, some of these endocrine disrupting chemicals can affect multiple generations, up to four and five generations down the line."
What to do if you think you might've been exposed to PBB
Marcus says people who are concerned that they may have been exposed to PBB should educate themselves about the possible health effects of that exposure, and then discuss the issue with their doctor.
The website also provides information on how to obtain a blood test to determine if you were exposed to PBB. According to the site, it takes 15 years, on average, for half of the PBB in the body to be eliminated and there are no known treatments that will reduce the levels.
**Clarification - an earlier version of this post said, "About 4,000 people in Michigan ate contaminated milk, beef, and eggs." That number was intended to describe the study cohort - those people who signed up to be part of the PBB Registry. The copy has been clarified above.