Seasonal Aerosol Composition and Source Apportionment of PM10 2001 to 2002 in Chillan, Chile

摘要

Most air pollution studies in Chile have been done in the Santiago urban area, which suffers from heavy air pollution during the winter season (Artaxo et al., Rojas et al., Jorquera et al.). Chile is a long narrow country bordered by the Pacific Ocean. It has a Central Valley in the north-south direction, with the Andes Mountains along the east and the Coast Mountains along the west. Between September 2001 and August 2002, inhalable particulate matter (PM_(10)) samples were collected at three sites in the city of Chillán to classify its air pollution. The city of Chillán is located in the northern central part of the Bio Bío region about 400 km south of Santiago at 36deg34minS latitude and 72degW longitude, and 144 m altitude above sea level. It has a population near 200,000 inhabitants with an urbanized surface area of 2,010 hectares. The surrounding lands are the result of fluvial and volcanic deposits, characterized by a generally flat topography with smooth slopes. These deposits were transported from the Andes Mountain by rivers as a result of huge volcanic and torrential events (Celis et al.). Its climate is Mediterranean with a prolonged dry season, followed by a humid period with 1,100 mm annual average rainfall (Celis et al.). November is typically a dry windy time that suspends soil dust that covers the Central Valley. Also, agricultural activities such as plowing and harvesting emit more dust, especially near December (Celis et al.,Carvacho et al.). There is a direct association between atmospheric inhalable particulate matter, PM_(10), and people's health. Exposure to increased PM_(10) shows a high correlation with increased respiratory diseases, pulmonary damage and mortality among the population. Only a few such studies have been conducted in Chile outside of Santiago. (Celis et al., 2004).