Analysis of Criteria Air Pollutant Trends in Three Mexican Metropolitan Areas

Sandy-Edith Benítez-García,Masahide Kawano,Yukiyo Okazaki,Isao Kanda,Shinji Wakamatsu

doi:10.3390/atmos5040806

Sandy-Edith Benítez-García, Masahide Kawano + Show 3 more

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https://doi.org/10.3390/atmos5040806

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Journal: Atmosphere	Publication Date: Nov 5, 2014
Citations: 19	License type: CC BY 4.0

Affiliation: Ehime University

Abstract

Data from the annual, seasonal, and hourly behavior of the criteria air pollutants CO, NO2, SO2, O3, and PM10 in three Mexican metropolitan areas (the Mexico City Metropolitan Area (MCMA), Guadalajara Metropolitan Area (GMA), and Monterrey Metropolitan Area (MMA)) over the period 2000–2011 were analyzed; and compliance with Mexican air quality standards was evaluated, highlighting causes of specific episodes of high and low concentrations. Data analyzed were collected from automatic air-monitoring networks located in the MCMA (32 stations), GMA (8 stations), and MMA (5 stations). In the MCMA and MMA, correlations between wind direction and concentrations of SO2 suggest that there was a considerable contribution of trans-boundary transport from outside of these areas. Analysis of annual trends revealed large reductions of CO in the MCMA, and SO2 in the three metropolitan areas. However, the annual mean concentration of O3 increased by 47% and 42% in the GMA and MMA, respectively, from 2000 to 2011, but decreased by 13% in the MCMA from 2005 to 2010. The annual mean concentration of PM10 in the MMA was about 58% and 76% higher than that in the MCMA and GMA, respectively, from 2001 to 2010.

Highlights

The Mexico City Metropolitan Area (MCMA), Guadalajara Metropolitan Area (GMA), and Monterrey Metropolitan Area (MMA) are the largest urban areas in Mexico
We collected continuous hourly data for air pollutants designated as criteria species by Mexican legislation (CO, NO2, SO2, O3, and PM10; Table 2) from automatic air-monitoring networks located in the MCMA (32 stations), GMA (8 stations), and MMA (5 stations)
The concentrations of CO, NO2, SO2, and PM10 were high in the dry-cold season (December to February) and the concentration of O3 was high in spring (March to June)

Summary

Introduction

The Mexico City Metropolitan Area (MCMA), Guadalajara Metropolitan Area (GMA), and Monterrey Metropolitan Area (MMA) are the largest urban areas in Mexico. These areas have the highest population densities, highest growth rates, and most industrial establishments in Mexico; they provide the greatest economic contributions to the country [1]. The situation has improved substantially for the criteria of air pollutants NO2, CO, and SO2 because of enforcement of environmental regulations, the concentrations of O3 and particulate matter with an aerodynamic diameter less than 10 μm (PM10) have remained high. Considerable research on high-ozone episodes in the MCMA; the influence of fossil fuel consumption on the air quality of MCMA; and photochemical reactions, the fate of volatile organic compounds (VOCs), and aerosol formation has been carried out [4,5,6,7,8,9,10]

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