Mutagenicity of the organic fraction of World Trade Center dust

Most studies of the health effects and chemical characterization of the dust resulting from the catastrophic collapse of the World Trade Center (WTC) on September 11, 2001, have focused on the large inorganic fraction of the dust; however, chemical analyses have identified mutagens and carcinogens in the smaller organic fraction. Here, we determined the mutagenicity of the organic fraction of WTC dust in Salmonella. Only 0.74% of the mass of the particulate matter (PM) < 53 mu m in diameter was extractable organic matter (EOM). Because the EOM was 10 times more mutagenic in TA100 +S9 than in TA98 +S9 and was negative in TA98 -S9, we inferred, respectively, that polycyclic aromatic hydrocarbons (PAHs) played a role in the mutagenicity and not nitroarenes. In TA98 +S9, the mutagenic potency of the EOM (0.1 revertant/mu g EOM) was within the range of EOMs from air and combustion emissions. However, the EOM-based mutagenic potency of the particles (0.0007 revertants/mu g PM) was 1-2 orders of magnitude lower than values from a review of 50 combustion emissions and various air samples. We calculated that 37 PAHs analyzed previously in WTC EOM were 5.4% of the EOM mass and 0.04% of the PM mass; some air contained 0.3 mu g WTC EOM/m(3) (0.02 mu g PAHs/m(3)). Populations exposed to WTC dust have elevated levels of prostate and thyroid cancer but not lung cancer. Our data support earlier estimates that PAH-associated cancer risk among this population, for example, PAH-associated lung cancer, was unlikely to be significantly elevated relative to background PAH exposures.

Automated summary

This study focuses on the health effects and chemical characterization of the organic fraction of the dust resulting from the collapse of the World Trade Center. The research demonstrates that the organic fraction contains mutagens and carcinogens, particularly polycyclic aromatic hydrocarbons (PAHs). While the organic fraction is small in proportion to the dust, it has a higher mutagenic potency. However, the overall mutagenic potency of the particles is lower compared to other sources. The study also found that populations exposed to the dust have elevated levels of prostate and thyroid cancer, but not lung cancer.