Science Inventory

Mutagenicity of the Organic Fraction of World Trade Center Dust

Citation:

Demarini, D., S. Warren, AND L. Brooks. Mutagenicity of the Organic Fraction of World Trade Center Dust. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS. John Wiley & Sons, Inc, Hoboken, NJ, 64(1):16-25, (2023). https://doi.org/10.1002/em.22519

Impact/Purpose:

Responders and the general public have been exposed to significant concentrations of dust following the collapse of the World Trade Center on September 11, 2001. Most studies of the health effects and chemical characterization of the dust have focused on the large inorganic fraction of the particles; however, a few studies have identified mutagens and carcinogens in the less-abundant organic fraction. This study provides additional genotoxicity data which aid in the evaluation of long term health effects of such events as well as informing detection and monitoring to ensure responder and public health.

Description:

Most studies of the health effects and chemical characterization of the dust resulting from the catastrophic collapse of the World Trade Center on September 11, 2001, have focused on the large inorganic fraction of the particles; however, a few studies have identified mutagens and carcinogens in the less-abundant organic fraction. Here, we examined further the organic fraction of WTC dust. We found that only 0.4% of the mass of the particulate matter (PM) <53 µm in diameter (PM53) (most of the settled particles were larger) was extractable organic matter (EOM). This EOM required metabolic activation (S9) to be mutagenic in strains TA98 and TA100 of the Salmonella mutagenicity assay, it was 10 times more potent in TA100 than in TA98, and it was not mutagenic in TA98 without S9. Thus, we infer that most of the mutagenic activity was likely due to polycyclic aromatic hydrocarbons (PAHs) and none to nitroarenes. In strain TA98 +S9, the mutagenic potency of the EOM (0.2 revertants/µg EOM), the EOM-based mutagenic potency of the particles (0.0008 revertants/µg particles), and estimated EOM-based mutagenic potency of the air in the vicinity during the month after the event (0.03 revertants/m3) were orders of magnitude lower than values for a wide variety of other combustion and ambient air particles. We conclude that the organic fraction contributed little to the mutagenicity of WTC dust particles, supporting earlier estimates that PAH-associated cancer risk among those exposed to WTC dust was unlikely to be elevated significantly relative to background PAH exposures.