Contaminación intradomiciliaria en un sector de extrema pobreza de la comuna de La Pintana / Indoor air pollution in a zone of extreme poverty at La Pintana community, Santiago

Background: Indoor pollution can be an important risk factor for human health, considering that people spend more than 60 percent of their time in their houses. Aim: To investigate indoor pollution in a zone of extreme poverty in Metropolitan Santiago. Material and methods: During 24h, carbon monoxide (CO), sulfur dioxide (SO2), respirable particulate matter (PM10), polycyclic aromatic hydrocarbons absorbed in PM5, temperature and humidity, were measured in the interior of 24 houses in La Pintana, Santiago. Results: The higher pollutant concentrations were observed during hours when heating was used, in houses that used coal (mean PM10 250 µg/m3, CO 42 ppm, SO2 192 ppb) or firewood (mean PM10 489 µg/m3, CO 57 ppm, SO2 295 ppb). In all houses, polycyclic aromatic hydrocarbons were detected and they came from the interior of the house and not from external filtered air. Coal, firewood and cigarette smoke were important sources of carcinogenic and kerosene and gas were sources of non carcinogenic polycyclic aromatic hydrocarbons. Conclusions: In the houses studied, the population was exposed to an accumulation of highly toxic pollutants, caused by a lack of ventilation. A high relative humidity also contributed to the growth of biological pollutants

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

Genotoxicidad de extractos orgánicos obtenidos del material particulado del aire de Santiago de Chile / Genotoxicity of organic extracts obtained from air particles at Santiago de Chile

La prueba de Ames ensayada con diferentes cepas de salmonella Typhimurium fue utilizada para determinar el poder mutagénico de extractos orgánicos de muestras provenientes del material particulado del aire de Santiago tomadas en una de las estaciones de la Red MACAM, (monitoreo automático de conmtaminantes atmosféricos y variables meteorológicas), entre los meses de Marzo y Agosto de 1990. Los ensayos se realizaron con las cepas TA98, TA98NR y TA98/I DNP6 en presencia o ausencia de fracción 89. Las muestras analizadas presentaron un alto poder mutagénico cuando se utilizó la cepa TA98 en presencia o ausencia de fracción 89, indicando que el aire de Santiago contiene agentes mutagénicos, indirectos principalmente hidrocarburos aromáticos y policíclicos (HAPs) y agentes mutagénicos directos que no requieren activación metabólica. La mutagenicidad de las muestras de Santiago fue mucho mayor que la obtenida en investigaciones realizadas en otros países. Estudios con la cepa TA 98 NR, deficiente en nitroreductasas y en enzimas que esterifican hidroxilamina, revelan que los extractos analizados contienen también mononitro y dinitroarenos. Estos últimos compuestos que se pueden generar por reacciones fotoquímicas entre HAPs, ozono y óxidos de nitrógeno o en la combustión de motores Diesel, han sido descritos como de muy alta actividad mutagénica. La presencia de HAPs y nitroarenos en los extractos permiten concluir que el aire de Santiago contiene agente químicos que potencialmente presentan un grave riesgo para la salud de la población