Background
This study provides an assessment of the health effects due to exposure to particulate matter PM2.5 (diameter < 2.5 µm that cause the air to appear hazy when levels are elevated) in three medium size cities of north western Mexico (Los Mochis, Culiacan and Mazatlan). We computed the total avoidable premature mortality, avoidable cardiovascular disease, gains in life expectancy, as well as the economic costs by air contamination corresponding to PM2.5. To achieve this goal, the Health Impacts Assessment (HIA) methodology provided by the European Aphekom Project was used. People in these cities are exposed to high PM2.5 concentrations that exceed limits implemented in domestic and international guidelines.
Results
We determined the cost of the PM2.5 pollutant associated with health outcomes under two different scenarios: Official Mexican Standard (NOM, Spanish acronym) and World Health Organization (WHO). The mean PM2.5 concentrations in 2017 were 22.8, 22.4 y 14.1 µg/m3 for the cities Los Mochis, Mazatlan and Culiacan, respectively. The mean avoidable mortality for all causes associated to the exposure to PM2.5 in the three cities was 638 for the NOM scenario (i.e., with a reduction to 12 µg/m3) compared to 739 for the WHO scenario (reduction to 10 µg/m3). Complying with the WHO guideline of 10 µg/m3 in annual PM2.5 mean would add up to 15 months of life expectancy at age 30, depending on the city.
Conclusions
The mean economic cost per year of the PM2.5 effects on human life in these three cities was $600 (NOM scenario) and $695 million dollars (WHO scenario). Effective public health and industrial policy interventions are socially advantageous and cost-saving to promote better health.