Association between Short-Term Exposure to Criteria Air Pollutants and Daily Mortality in Mexico City: A Time Series Study

Abstract

The short-term effects of air pollution on the health of residents in the metropolitan area of Mexico City (MAMC) were assessed in 11 municipalities from 2012 to 2015 using a time-series approach. Site 11 (Azcapotzalco) presented values above the limit of the Mexican regulations for SO2, while values above the limit were found for CO for the city’s other municipalities. Site 8 (Cuauhtemoc) presented the highest number of values above the maximum permissible limit for NO2, while site 1 (Alvaro Obregon) presented the highest number of values above the limit for O3. Finally, site 7 (Venustiano Carranza) presented the highest number of values above the limit for PM10. In general, the southeast and northwest of the city presented high levels of pollution for the criteria air pollutants: SO2, NO2, and PM10, while the southeast presented the highest levels for O3. A great number of associations were found between daily mortality and a 10% increase in the concentrations of most of the pollutants tested, for most of the municipalities of the city. Significant relative risk index (RRI) increases were found for people >60 years of age for all pollutants and municipalities, increases which resulted from a 10% increase in the daily mean concentrations of all pollutants tested. As the RRIs observed were low but significant, the findings are, thus, of public concern. The present study demonstrated that older people are at considerable risk from atmospheric pollution.