Mercy J. Borbor-Cordova:
Integrating environmental sciences and human dimensions: air pollution and human health
Air pollution is an increasing environmental problem in developing countries with high rates of urbanization. In 2000, 75% of the population in Latin America was living in cities and megacities (UNPD, 2001). Together with a steep urban annual growth rate (1.18%), growing vehicular fleets, limited urban infrastructure and public services, land use conflicts among residential and industrial activities, and permanent rural-urban migration patterns, air pollution in the major urban centers of Latin America has become a serious health concern.
In Guayaquil, the largest city of Ecuador with a population of 2.6 million people, air pollution is not perceived as a municipal environmental problem. However, two impoverished communities within the city have to face daily the impacts of power plants, ports, and shipping activities. As in many cities in developing countries, time series air quality data is sparse, and even less is known about the possible impacts of air pollution in the population's health. Thus, together with an interdisciplinary group of researchers and city officers, I have been working on this Ecohealth pilot project to investigate the impact of the particulate matter produced by anthropogenic activities on the respiratory health of children in these two communities (More about ecohealth approach, http://www.idrc.ca/ecohealth/).
This is a transdisciplinary project that uses an ecosystems approach which includes: a) an emissions inventory, air dispersion model, and the monitoring of fine and coarse particulate matter, b) epidemiological studies: historical cohort study and a case-control study of acute respiratory illness (ARI) in children; and c) a stakeholders participatory process to identify the alternatives for air quality management. This project was reviewed and approved by the Human Subject Committee at NCAR to fulfill the ethics standards required for human research. Written informed consent was obtained from the children's parents that participate in the case-control study with a spirometry lung function test. This study aimed to investigate association between short-term variation in air pollutants levels (PM10, PM2.5) and lung function of children at the two study sites. The protocols applied in the spirometry tests follow the guidelines of the American Thoracic Society (1995).
At the site 1 (Fig 1) there are 3 fossil fuel fired power plants and in the site 2 there are harbor activities associated with banana, organic, and inorganic product shipping. We applied a statistical correlation analysis among the levels of particulate matter, meteorological factors, and the number of cases of acute respiratory infections (ARI). We found that there is a significant statistical correlation between particulate matter (PM10, PM2.5) and the number of patients with ARI. Moreover, although the levels of particulate matter (PM10) are under the national standard (150 ug/m3 in 24 hours), our analysis suggests that even those levels are affecting the respiratory health of the people in the two sites.
The case-control study with spirometries tests on children (ages 6-14) (Fig 2) found that most of the spirometries are in the normal range, with less than 15% of the tests suggesting reduction in the lung and forced expiration capacity. However, we found that in areas closest to high exposition sites such as high traffic roads, and busy ports, there was an 18: 1 greater probability of a child contracting a respiratory illness. We also found that most of the conditions of acute respiratory infections are of an obstructive nature linked to the superior respiratory system (airways). Because the study was short term, we suggest developing a long term monitoring program of targeted child populations exposed to point source emissions.
The results of the pilot project suggest looking for integrated solutions where community, industry, and government authorities take their share of responsibility towards finding solutions. It is important to establish options that may include emissions mitigation, a monitoring air quality system-network, and a better epidemiological surveillance system as a precautionary measure to track the respiratory health of the population in the medium and long terms.
This project was funded by the International Development Center of Canada and the Fiocruz Foundation of Brazil, with the collaboration of the Municipality of Guayaquil, the Escuela Superior Politecnica del Litoral and the Instituto Nacional de Meteorologia e Hidrologia of Ecuador.
Fig 1. Study Site 1: housing in the vicinity of the power plants in Guayaquil.
Fig.2 .- Spirometry is the most common of the Pulmonary Function Tests, measuring especially the amount (volume) and speed (flow) of air that can be inhaled and exhaled.
Mercy Borbor-Cordova receives support from the Inter-American Institute for Global Change Research and the National Center for Atmospheric Research.
Presentation from the Summer School 2007, University of Gottingen (11.2 MB) Estuary_ LU_Guayas.pdf
ASP Spotlight September 2007
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