Comparative study of the mutagenic and genotoxic activity associated with inhalable particulate matter in Rio de Janeiro air.
We have determined the genotoxic and mutagenic activities associated with inhalable particulate matter (IPM) collected in Rio de Janeiro, Brazil, Camden, NJ, and Caldecott Tunnel, CA, and used these results to compare three different bioassays. Samples collected every 12 hr (Rio) or every 24 hr (Camden) were extracted sequentially with cyclohexane (CX), dichloromethane (DCM), and acetone (ACE), for a rough fractionation by polarity, and composites of the extracts were tested for mutagenicity using the Salmonella frame shift (TA98) and base substitution (TA100) tester strains, as well as for genotoxicity using the Rossman Microscreen bioassay based on the induction of lambda-prophage in a lysogenic Escherichia coli strain. All samples were tested without and with S9 metabolic activation. Maximum mutagenic and genotoxic activities were in the nonpolar (CX) and polar (ACE) fractions, respectively, indicating that these two assays detect different classes of compounds with different efficiencies. Oxidative aging of the Rio aerosol is indicated by a shift in activities in both tests from the less polar fractions in the day to the polar (ACE) fraction at night. The Rio TA98 mutagenic (18 rev/m3) and genotoxic (1.4 x 10(5) PFU/m3) activities were higher than those for Camden, an Eastern U.S. city, by factors of 1.4 and 2.8, respectively.
Miguel
A G
AG
Biophysics Institute, Federal University of Rio de Janeiro, Brazil.
Daisey
J M
JM
Sousa
J A
JA
D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D010582:Bacteriophage lambda / Q000187:drug effects; D001711:Biotransformation; D001938:Brazil; D066298:In Vitro Techniques; D008297:Male; D009152:Mutagenicity Tests / Q000379:methods; D009153:Mutagens; D051381:Rats; D012486:Salmonella typhimurium / Q000187:drug effects; D012997:Solvents; D013997:Time Factors; D014481:United States; D014775:Virus Activation / Q000187:drug effects
D000393:Air Pollutants; D009153:Mutagens; D012997:Solvents