Researchers from the Boston University (BU) and Duke University Superfund Research Program (SRP) Centers found that components of the flame-retardant mixture Firemaster® 550 (FM550) may stimulate growth of fat cells and reduce bone health. The results of the collaborative study suggest that triphenyl phosphate (TPP), a component of FM550 that is widespread in household products and house dust, interacts with a protein that regulates fat cell differentiation and lipid storage.
“TPP is everywhere in our indoor environment, so our finding that TPP is biologically active is significant and warrants further investigation,” said BU SRP project leader Jennifer Schlezinger, Ph.D., who led the study. “This calls attention to the fact that we need to be considering the contributions of environmental toxicants such as TPP in obesity and loss of bone health.”
Alternative flame retardant use has increased since the phase out of pentabromodiphenyl ethers (PBDEs) because of concerns about the tendency of PBDEs to concentrate in human tissues and potential human health effects. Other chemicals are currently used to meet flammability requirements, including FM550, which is found in foam-based products such as couch cushions and other household items.
Scientists tested the ability of FM550 to bind and activate peroxisome proliferator activated receptor gamma (PPARγ), a protein known to regulate the development of fat cells in the body. Researchers also used cells from bone marrow to assess changes in response to exposure to TPP and other components of FM550.
FM550 was shown to bind and activate PPARγ and stimulate development of fat cells, which may contribute to obesity. PPARγ also plays a crucial role in stimulating formation of fat cells in bone marrow, which suppresses the formation of osteoblasts, or bone cells. By activating PPARγ, components of FM550, including TPP, potentially have detrimental effects on bone health and may accelerate osteoporosis by suppressing osteoblast formation.
Based on the findings, TPP is likely a major contributor to the biological actions of FM550. Given that TPP is very common in house dust, the authors suggest the need for further studies to evaluate its health effects.