PM can be considered as the atmospheric pollutant that mostly affects human health. The International Agency for Research on Cancer (IARC) has recently classified air pollution and fine PM as carcinogenic to human (1 Group) (Loomis et al. 2013). Different studies showed that PM induces several kinds of adverse cellular effects as cytotoxicity, mutagenicity, DNA damage and stimulation of cytokine production (Moller et al., 2015). The aim of the MAPEC study is to evaluate the association between air pollution (in particular PM) and early biomarkers in oral mucosa of children recruited from first grade schools of 5 Italian towns characterized by different PM levels. This work aims to evaluate children exposure to urban air pollution investigating the mutagenic and genotoxic effect of PM0.5 samples. PM0.5 samples (n=36) were collected (72h) in the school area on the same days of biological samplings in two different seasons (winter 2014-2015 and spring 2015) using a high-volume air sampler. PM0.5 organic extracts were chemically analyzed (PAH, Nitro-PAH) and tested on A549 by the comet assay and micronucleus test and on Salmonella strains (TA100, TA98, TA98NR and YG1021) by Ames test. Results showed that PM0.5 represents a very variable PM10 percentage (range 19.6-63% and 9.9-55.9% in winter and spring respectively). In winter PM10 concentration was generally lower than 50µg/m3 (EU daily limit) with highest values in the towns of the Padana plain. Generally lower values were observed in spring. In winter all PM0.5 extracts showed at least one mutagenic dose with the TA98 strain (net revertant/m3 range 0.3-1.5) suggesting the presence of indirect mutagens (+S9), while a lower effect was observed with the TA100 strain. The results obtained with the TA98NR and YG1021 strains in both seasons showed the presence of nitroaromatic compounds as confirmed by the chemical analysis. Lower effects and also a lower nitroaromatic compounds level were generally observed in spring. No genotoxic or oxidative effect of PM0.5 extracts was observed using the comet assay (with/without Fpg enzyme) and micronucleus test in both seasons except for some sporadic samples. The low biological effect observed in winter could be related to the low level of air pollution observed in this winter sampling associated to a high atmospheric instability. The high variability of PM0.5 observed in this study should be more investigated. Moreover for a greater understanding of the relationship between PM size, composition and biological effects, the results obtained in this study suggest to investigate also the biological effect of the other PM fractions and in particular of the PM0.5-1 fraction.
MUTAGENIC/GENOTOXIC EFFECT OF PM0.5 COLLECTED IN FIVE ITALIAN TOWNS IN TWO SEASONS: RESULTS OF THE MAPEC STUDY
BONETTA, Sara;BONETTA, SILVIA;ROMANAZZI, VALERIA;SCHILIRO', Tiziana;PIGNATA, Cristina;GILLI, Giorgio;CARRARO, Elisabetta;
2016-01-01
Abstract
PM can be considered as the atmospheric pollutant that mostly affects human health. The International Agency for Research on Cancer (IARC) has recently classified air pollution and fine PM as carcinogenic to human (1 Group) (Loomis et al. 2013). Different studies showed that PM induces several kinds of adverse cellular effects as cytotoxicity, mutagenicity, DNA damage and stimulation of cytokine production (Moller et al., 2015). The aim of the MAPEC study is to evaluate the association between air pollution (in particular PM) and early biomarkers in oral mucosa of children recruited from first grade schools of 5 Italian towns characterized by different PM levels. This work aims to evaluate children exposure to urban air pollution investigating the mutagenic and genotoxic effect of PM0.5 samples. PM0.5 samples (n=36) were collected (72h) in the school area on the same days of biological samplings in two different seasons (winter 2014-2015 and spring 2015) using a high-volume air sampler. PM0.5 organic extracts were chemically analyzed (PAH, Nitro-PAH) and tested on A549 by the comet assay and micronucleus test and on Salmonella strains (TA100, TA98, TA98NR and YG1021) by Ames test. Results showed that PM0.5 represents a very variable PM10 percentage (range 19.6-63% and 9.9-55.9% in winter and spring respectively). In winter PM10 concentration was generally lower than 50µg/m3 (EU daily limit) with highest values in the towns of the Padana plain. Generally lower values were observed in spring. In winter all PM0.5 extracts showed at least one mutagenic dose with the TA98 strain (net revertant/m3 range 0.3-1.5) suggesting the presence of indirect mutagens (+S9), while a lower effect was observed with the TA100 strain. The results obtained with the TA98NR and YG1021 strains in both seasons showed the presence of nitroaromatic compounds as confirmed by the chemical analysis. Lower effects and also a lower nitroaromatic compounds level were generally observed in spring. No genotoxic or oxidative effect of PM0.5 extracts was observed using the comet assay (with/without Fpg enzyme) and micronucleus test in both seasons except for some sporadic samples. The low biological effect observed in winter could be related to the low level of air pollution observed in this winter sampling associated to a high atmospheric instability. The high variability of PM0.5 observed in this study should be more investigated. Moreover for a greater understanding of the relationship between PM size, composition and biological effects, the results obtained in this study suggest to investigate also the biological effect of the other PM fractions and in particular of the PM0.5-1 fraction.
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