Persistent organic pollutants enter the environment by many different routes. In the home, chemicals such as brominated flame retardants are present in furniture and textiles and become part of the home environment over time as the fabrics degrade. Researchers are just now beginning to understand how such chemicals enter the human body and interact with endocrine and other systems. This case examines the long-term consequences of accidental exposure to polybrominated biphenyl through livestock feed in Michigan. While not a typical domestic exposure, it illustrates how the health effects of these chemicals can persist across generations, potentially affecting children who never directly interacted with the chemical.
The contamination of animal feed in Michigan with PBB has had devastating health effects on many Michigan families. It also provided researchers with an opportunity to study the how these chemicals interact with the environment and with the human body of long periods of time. Now that nearly 5 decades have passed since the contamination occurred, we have learned a great deal about the persistence of these chemicals within the body, and their lasting health effects.
1) Briefly describe the chemical nature of PBB. What characteristic of this molecule accounts for its persistence in the human body? Where within the body is PBB stored? (answer in 3-4 sentences)
2) What are two physiologic mechanisms by which PBBs alter the function of the human body? (answer in 4-6 sentences)
3) When congenital abnormalities occur in a child whose mother who was exposed to a toxin earlier in life, the assumption is often that toxin still present in the mother’s body is responsible for the abnormality in the child. However, in the “Uncertain Inheritance” article, Jim and Ida Hall, whose daughter died at age 2 from a congenital heart defect, questioned Jim’s exposure to PBBs during his childhood could have been responsible. Ida did not live in the contaminated area as a child, so was not exposed. By what mechanism could Jim’s exposure lead to an abnormality in his daughter? (Answer in 4-6 sentences)
4) Based on the data gathered so far, do you believe that a parent or grandparent’s PBB exposure could plausibly affect the health of children with no exposure to the chemical? Should robust evidence of this phenomenon emerge, how should this new knowledge change how these types of chemicals are regulated, and how we hold companies responsible for contamination with these chemicals? Propose an ethical solution that appropriately compensates the affected parties without overly burdening companies that were unaware of the risks of their products. (Answer in about 8 – 10 sentences).
