Particulate matter levels in a South American megacity: the metropolitan area of Lima-Callao, Peru

• Autores: Silva, José, Rojas Quincho, Jhojan Pool, Norabuena Espinoza, Magdalena, Molina, Carolina, Toro, Richard, Leiva-Guzmán, Manuel A.
• Formato: artículo
• Fecha de Publicación: 2017
• Institución: Servicio Nacional de Meteorología e Hidrología del Perú
• Repositorio: SENAMHI-Institucional
• Lenguaje: inglés
• OAI Identifier: oai:repositorio.senamhi.gob.pe:20.500.12542/234
• Enlace del recurso: https://hdl.handle.net/20.500.12542/234; https://doi.org/10.1007/s10661-017-6327-2.
• Nivel de acceso: acceso cerrado
• Materia: Contaminantes; Contaminación atmosférica; Condiciones atmosféricas; Ozono; https://purl.org/pe-repo/ocde/ford#1.05.08

The temporal and spatial trends in the variability of PM10 and PM2.5 from 2010 to 2015 in the metropolitan area of Lima-Callao, Peru, are studied and interpreted in this work. The mean annual concentrations of PM10 and PM2.5 have ranges (averages) of 133–45 μg m−3 (84 μg m−3) and 35–16 μg m−3 (26 μg m−3) for the monitoring sites under study. In general, the highest annual concentrations are observed in the eastern part of the city, which is a result of the pattern of persistent local winds entering from the coast in a south-southwest direction. Seasonal fluctuations in the particulate matter (PM) concentrations are observed; these can be explained by subsidence thermal inversion. There is also a daytime pattern that corresponds to the peak traffic of a total of 9 million trips a day. The PM2.5 value is approximately 40% of the PM10 value. This proportion can be explained by PM10 re-suspension due to weather conditions. The long-term trends based on the Theil-Sen estimator reveal decreasing PM10 concentrations on the order of −4.3 and −5.3% year−1 at two stations. For the other stations, no significant trend is observed. The metropolitan area of Lima-Callao is ranked 12th and 16th in terms of PM10 and PM2.5, respectively, out of 39 megacities. The annual World Health Organization thresholds and national air quality standards are exceeded. A large fraction of the Lima population is exposed to PM concentrations that exceed protection thresholds. Hence, the development of pollution control and reduction measures is paramount.