The effects of inhaled polychlorinated biphenyls on the liver

PCBs are persistent pollutants that were used in the production of many industrial and commercial products. They are associated with diabetes, cancer, and heart disease, and are contaminants in food products as well as the air of older buildings such as schools. There have been limited studies on how breathing in PCBs at an early age causes disease. We found that exposure of young female rats to a PCB found at high levels in the air of contaminated buildings caused an increase in liver genes responsible for making fat, indicating a potential role in causing fatty liver disease.

To study if diet increases the dangers associated with PCB exposure, young mice were given a fatty and sugary diet similar to what children consume in the U.S. (U.S. diet) and exposed to a PCB mixture which resembles that found in older school buildings. PCB-exposed mice had worsened insulin resistance and exhibited changes in the expression of genes that may make them more susceptible to diabetes. An additional study exposed both male and female mice to the PCB mixture and fed them either normal food or a U.S. diet. Genes involved in making fat in the liver were changed, but these changes seemed more linked to eating the U.S. diet rather than PCB exposure, and the observed changes were different between males and females. Overall, my research demonstrates that breathing in PCBs at an early age can influence liver disease and, along with diet, may promote metabolic disease later in life.