Influence of Atmospheric Air Pollution on Indoor Air Quality: Comparison of Chemical Pollutants and Mutagenicity Levels in Santiago (Chile)

The influence of atmospheric pollution on indoor air quality (IAQ) was studied in downtown Santiago (Chile). Carbon monoxide (CO), nicotine, the mass of respirable particulate matter below 5 μm (PM₅ fraction) and total and carcinogenic polycyclic aromatic hydrocarbons (PAHs) were simultaneously monitored indoors and outdoors in restaurants, offices and oth er places. The levels of CO changed simultaneously outdoors and indoors (r = 0.89), especially during traffic rush hours, masking the contribution of other indoor sources and showing the importance of infiltration of outdoor air indoors. CO concentrations ranged from 1.0 to 73 ppm and 0.5 to 93 ppm for indoors and outdoors, respectively. The highest running 8-hour average levels measured were 16 and 18 ppm, respectively. These levels exceeded the Chilean 8-hour standard of 9 ppm to the extent of 178% indoors and by more than 200% outdoors. PM₅ concentrations were high and showed no significant differences (p > 0.05) between indoors and outdoors: levels in restaurants, offices and other places were not significantly different from each other. The concentrations of total and carcinogenic PAHs were also high indoors and outdoors, outdoor levels being higher than those indoors although no significant differences (p > 0.05) in indoor levels were found between restaurants and offices and between 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 also found between offices and restaurants, and offices and other places. Mutagenic response in Salmonella typhimurium by organic extracts from PM ₅ collected in downtown Santiago in Bandera street and in a rural area showed that the extracts from the Santiago samples are highly mutagenic. These results suggest that in downtown Santiago, infiltration might be the main source of indoor pollution. Symptoms and health effects probably related to air pollution in people working in Bandera street and in Curacavi, a rural area located 45 km from Santiago were surveyed. This showed clearly that people working in downtown Santiago have greater frequency of eye complaints, sneezing attacks, cough, throat dryness and rhinitis.