Risk of leukemia in relation to exposure to ambient air toxics in pregnancy and early childhood.

There are few established causes of leukemia, the most common type of cancer in children. Studies in adults suggest a role for specific environmental agents, but little is known about any effect from exposures in pregnancy to toxics in ambient air. In our case-control study, we ascertained 69 cases of acute lymphoblastic leukemia (ALL) and 46 cases of acute myeloid leukemia (AML) from California Cancer Registry records of children

Validity of biomarkers in environmental health studies: the case of PAHs and benzene.

Exposure biomarkers, which have long been restricted to the framework of occupational hygiene, currently arouse increasing interest in the field of environmental pollution. To assess their validity, we propose here a conceptual framework that is based on their intrinsic characteristics and on properties related to the procedures for their analysis. The most important criteria are specificity for the toxic substance under consideration and sensitivity, that is, the ability to distinguish contrasted levels of exposure. Their analytic sensitivity and specificity are also important. Fulfilling these criteria is especially important in the context of environmental pollution, because the levels of exposure, and thus the contrasts, are low. This framework is used to assess the validity of some biomarkers for polycyclic aromatic hydrocarbons (1-hydroxypyrene and DNA adducts) and for benzene (urinary and serum benzene, trans,trans muconic acid, and S-phenylmercapturic acid). This evaluation shows that the most relevant biomarkers for estimating individual exposure to environmental pollution are 1-hydroxypyrene for polycyclic aromatic hydrocarbons and urinary benzene and S-phenylmercapturic for benzene.

Influencia de la contaminación atmosférica en la calidad de aire de interiores / Influence of outdoor pollution on indoor air quality

The influence of outdoor pollution on indoor air quality was studied in downtown Santiago (Bandera street). Carbon monoxide (CO), nicotine, particulate matter, respirable fraction (PM5) and total and carcinogenic polyaromatic hydrocarbons (PAHs) were simultaneously monitores indoors and outdoors and indoors in restaurants, offices and other places. The levels of CO changed simultaneously outdoors and indoors (r=0.89) specially during traffic rush hours, demonstrating the importance of outdoor infiltration into the indoor air quality and masking the contribution of other CO indoor sources. The maximun CO concentrations were over 800 percent and over 1000 percent higher indoors and outdoors respectively than the 9 ppm CO National Ambient Air Quality. The PM5 concentrations were very high and showed no significant differences (p>0.05) from indoor to outdoors, or between indoor levels in restaurants, offices and other places. Total ans carcinogenic PAHs levels were also very high, outdoors and indoors, outodoor levels being generally higher than those indoors and no significant; differences (p>0.05) were found for the indoor levels between restaurants, offices and other places. Nicotine levels showed significant differences (p<0.05) between indoor and outdoor levels. In addition, great differences (p<0.05) in indoor levels, were found between offices and restaurants, and offices and other places. Among indoor sources cigarrete smoke seems to be a minor source since nicotine concentrations, bieng 2.3 times higher in restaurants and other places than in offices, do not contribute to enhance significantly PM5 and total and carcinogenic HAPs in the first ones. These results suggest that in downtown Santiago, infiltration might be the main source of indoor pollution. This is supported by 2 evidences: a) coronene, a tracer of vehicle emissions was found in high concentraion indoors and b) in restaurants (in wich PAHs emissions might be higher indoor) a correlation coefficient of 0.987 for the indoor and outdoor concentrations of carcinogenic PAHs was found. Furthermore a survey asking for different symptoms and effects probably related to air pollution was made to people working in Bandera and in a rural area located 40 Km from Santiago. The results showed that excluding smoking as a confounded factor, people working in Bandera showed a significantly greater (p<0.05) risk of ill effects on their health than people working in the rural area