Evaluating the mutagenicity of the water-soluble fraction of air particulate matter: A comparison of two extraction strategies.
Many studies have focused on assessing the genotoxic potential of the organic fraction of airborne particulate matter. However, the determination of water-soluble compounds, and the evaluation of the toxic effects of these elements can also provide valuable information for the development of novel strategies to control atmospheric air pollution. To determine an appropriate extraction method for assessing the mutagenicity of the water-soluble fraction of PM, we performed microwave assisted (MW) and ultrasonic bath (US) extractions, using water as solvent, in eight different air samples (TSP and PM10). Mutagenicity and extraction performances were evaluated using the Salmonella/microsome assay with strains TA98 and TA100, followed by chemical determination of water-soluble metals. Additionally, we evaluated the chemical and biological stability of the extracts testing their mutagenic potential and chemically determining elements present in the samples along several periods after extraction. Reference material SRM 1648a was used. The comparison of MW and US extractions did not show differences on the metals concentrations, however positive mutagenic responses were detected with TA98 strain in all samples extracted using the MW method, but not with the US bath extraction. The recovery, using reference material was better in samples extracted with MW. We concluded that the MW extraction is more efficient to assess the mutagenic activity of the soluble fraction of airborne PM. We also observed that the extract freezing and storage over 60 days has a significant effect on the mutagenic and analytical results on PM samples, and should be avoided.
Dept. Environmental Analyses, São Paulo State Environmental Agency, CETESB, Av. Prof. Frederico Hermann Jr, 345, 05459-900, São Paulo, SP, Brazil; Dept. Clinical Analyses and Toxicology, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Professor Lineu Prestes, 580, 05508-000, São Paulo, SP, Brazil. Electronic address: icpb@usp.br.
Isabel C
IC
Palacio
Dept. Environmental Analyses, São Paulo State Environmental Agency, CETESB, Av. Prof. Frederico Hermann Jr, 345, 05459-900, São Paulo, SP, Brazil. Electronic address: ifoliveira@sp.gov.br.
Ivo F
IF
Oliveira
Dept. Environmental Analyses, São Paulo State Environmental Agency, CETESB, Av. Prof. Frederico Hermann Jr, 345, 05459-900, São Paulo, SP, Brazil. Electronic address: rfranklin@sp.gov.br.
Robson L
RL
Franklin
Dept. Clinical Analyses and Toxicology, Faculty of Pharmaceutical Sciences, University of São Paulo, Av. Professor Lineu Prestes, 580, 05508-000, São Paulo, SP, Brazil. Electronic address: smbarros@usp.br.
Silvia B M
SB
Barros
Dept. Environmental Analyses, São Paulo State Environmental Agency, CETESB, Av. Prof. Frederico Hermann Jr, 345, 05459-900, São Paulo, SP, Brazil. Electronic address: droubicek@sp.gov.br.
Deborah A
DA
Roubicek
D000393:Air Pollutants / Q000032:analysis*; D002623:Chemistry Techniques, Analytical; D008670:Metals / Q000494:pharmacology; D008861:Microsomes; D008872:Microwaves; D009152:Mutagenicity Tests / Q000379:methods*; D009153:Mutagens / Q000633:toxicity*; D052638:Particulate Matter / Q000633:toxicity*; D012486:Salmonella typhimurium / Q000187:drug effects; D012995:Solubility; D012997:Solvents; D014867:Water / Q000737:chemistry*
D000393:Air Pollutants; D008670:Metals; D009153:Mutagens; D052638:Particulate Matter; D012997:Solvents; D014867:Water
Air particulate matter; Extraction; Genotoxicity; Water-soluble fraction