Burning Problem: Toxic Flame Retardants in People and Wildlife
Pollution in People Report - Chapter 2 - Toxic Flame Retardants in People and Wildlife
Every day for the past twelve years, Dr. Patricia Dawson has risen at 5 a.m. to help women face breast cancer. Women from throughout the Northwest, hoping to purge their bodies of cancer and put their lives back together, come to Swedish Medical Center’s Comprehensive Breast Center, where Patricia is a surgeon. In Patricia’s line of work there is no denying disease, and she grapples every day with questions about the blame that can be placed on toxic chemicals and other environmental causes of cancer.
By submitting her hair, urine, and blood for chemical testing, Patricia sought to learn more about how our daily decisions and our government’s policies on toxic chemicals directly affect our lives. She was surprised by what her test results revealed: she is ingesting pesticides along with the nutrients from her otherwise healthful diet. Her body carries DDT and PCBs decades after these chemicals were banned. But perhaps most disturbing was the fact that somehow, her body has absorbed enough of the toxic flame retardants known as PBDEs to make her levels three times the national average.
Each of the ten Pollution in People participants tested positive for PBDEs, with levels ranging from 29 to 147 ppb (as measured compared to total fat in blood samples). With 147 ppb PBDEs in her blood, Patricia had the highest level in the group. The CDC has not included PBDEs in its ongoing program to test U.S. residents for toxic chemicals, but Tom McDonald, at the time a California EPA scientist, recently compiled six studies (with a total of 191 tested individuals) and found a median level of 47.9 ppb in tested women nationally (McDonald 2005), a level comparable to the median in our study, 47.5 ppb.
McDonald also back-calculated from the measured levels to estimate daily exposures for these women and compare them to exposure levels that caused harm in laboratory animals. His findings indicate that current levels in U.S. women are at or approaching those that could harm a developing fetus. Levels of PBDEs that caused behavioral problems in mice were just 4 to 11 times those of the most exposed U.S. women (those in the top five percent of tested women, with levels of 302 ppb and above). Rats suffer fertility problems—reduced sperm counts and changes to ovary cells—at levels at or lower than those of the most exposed women. Patricia’s level, at 147 ppb, is uncomfortably close to the approximately 230 ppb in affected rats. Generally, agencies seek to ensure a safety margin of at least 100, a margin that is much greater than that which exists today for many women.
Figure 2 shows PBDE levels in Pollution in People participants as compared to the national median.
Figure 2: PBDE levels, measured in blood serum and expressed on a lipid weight basis.