The Importance of International Collaboration in Wet Atmospheric Deposition and Air Quality
Rodolfo Sosa Echeverría1, Pablo S ánchez Alvarez1, Ana Luisa Alarcón Jiménez1, Mónica Jaimes Palomera2, Amelia Jiménez Alcántara3, David Gay4, and John Walker5
1 Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, Ciudad de México, México, 2 Secretaria de Medioambiente del Gobierno de la Ciudad de México, Ciudad de México, México, 3 Programa de Posgrado de Ingeniería, Universidad Nacional Autónoma de México, Ciudad de México, México, 4 National Atmospheric Deposition Program, Wisconsin State Lab of Hygiene, Madison, WI, 5 USDA Forest Service, Center for Forest Watershed Research, Otto, NC
Currently, addressing air pollution has undoubtedly proven more efficient by considering a comprehensive assessment of air quality and atmospheric deposition, in order to subsequently establish prevention, minimization, and control measures that benefit public health, as well as the protection of ecosystems and other receptors.
For more than a decade, the "Universidad Nacional Autónoma de México" (UNAM) and the National Atmospheric Deposition Program (NADP) have been collaborating on the evaluation of wet atmospheric deposition, air quality, and its interpretation in different regions, notably the Mexico City Metropolitan Area (MCMA) and the Gulf of Mexico Region.
For several decades, the MCMA has faced a challenge in terms of air pollution, currently experiencing poor air quality due to ozone and particulate matter, in addition to the problem of acid rain. This poses a significant health risk to more than 20 million inhabitants, and in the specific case of acid rain, there is a potential impact on ecosystems and materials. Since 2002, the Mexico City Government and the UNAM have collaborated continuously to operate the atmospheric deposition network. To date, several findings have been obtained, among which we can highlight the following: a) Despite the significant reduction in SO2 emissions, resulting in improved air quality, the sulfate ion remains the largest component of acidifying cations (SO42-/NO3- ratio of 1.5). b) Similarly, in the case of reactive nitrogen in wet atmospheric deposition, the NH4+/NO3- ratio is approximately 2.5, demonstrating a greater contribution of reactive nitrogen in its reduced form. c) In the Gulf of Mexico region, the highest value of the SO42-/NO3- ratio, which is on the order of 4, has been found at the only sampling site in Mexico (La Mancha). d) It is important to establish monitoring stations in Mexico comparable to those that exist in the United States, such as the National Trends Network (NTN), Ammonia Monitoring Network (AMoN), Atmospheric Mercury Network (AMNet) and Mercury Deposition Network (MDN), among others.