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Delayed human effects such as cancer could be a consequence of chronic exposure, over long periods of time, to inhalable (PM10) and respirable (PM2.5) particles containing environmental carcinogen mixtures. Air pollution in Santiago, Chile, is a major public health problem due to the high levels of regulated pollutants such as PM10, CO, and ozone. In this work, we studied the levels of polycyclic aromatic hydrocarbons (PAHs) onto PM10 and PM2.5 collected in diesel revision plants, in an urban area with a high flow of buses and trucks and in a rural area not exposed to diesel emissions. The PM10 average levels in diesel emission plants were higher than the Chilean PM10 standard and higher than those found in the urban and rural areas. In the urban area the PM10 average levels were lower than the Chilean PM10 standard, although some 24 h levels surpassed the levels established to decree preemergency or emergency and in some cases were higher than the levels reported by all the official monitoring stations. ...

Xenobiotic metabolizing enzymes, especially CYP1A1 and GSTM1, are involved in the activation and conjugation of PAHs and are controlled by polymorphic genes. PAHs released from diesel emissions in many cities of the world, especially in developing countries, contribute significantly to the toxic effects of airborne inhalable particles. We have evaluated the gene-environment interaction in Santiago of Chile, studying the contribution of CYP1A1 and GSTM1 polymorphisms on 1-OH-P urinary levels used as the PAHs exposure biomarker. The study was performed on 59 diesel exposed (38 diesel revision workers and 21 subjects working in an urban area as established street vendors) and 44 non-exposed subjects living in a rural area. The 1-OH-P urinary levels of the urban (P=0.043) and rural (P=0.040) populations showed, without considering the genotypes, significant differences between smokers and non-smokers, but no significant differences were found between smokers and non-smokers among the diesel plant workers (P=0.33). Non-smoking subjects of the diesel plants and the urban area showed similar 1-OHP levels (P=0.466) which were significantly higher than those of the subjects living in the rural area (P

This work studied the mutagenic potential and polycyclic aromatic hydrocarbon (PAH) levels onto PM10 collected in diesel revision plants, in an urban area as well as in a rural area in Santiago, Chile. The PM10 average levels in diesel emission plants during working hours (there is no occupational PM10 Chilean standard) were significantly higher than the atmospheric Chilean PM10 standard and highly mutagenic and with high PAHs levels. Additionally, we evaluated the contribution of CYP1A1 and GSTM1 polymorphisms on 1-OH-pyrene urinary levels. The diesel-exposed workers carrying the CYP1A1*2A allele showed significantly higher 1-OH-P levels than the subjects from the rural area with the same genotype. The higher levels of 1-OH-P were found in individuals carrying the combined CYP1A1*2A and GSTM1 null genotype. This kind of information might be relevant to establish prevention, protection, and mitigation actions to protect public health.