Effect of particulate matter (PM2.5 and PM10) on health indicators: climate change scenarios in a Brazilian metropolis

Recife is recognized as the 16th most vulnerable city to climate change in the world. In addition, the city has levels of air pollutants above the new limits proposed by the World Health Organization (WHO) in 2021. In this sense, the present study had two main objectives: (1) To evaluate the health (and economic) benefits related to the reduction in mean annual concentrations of PM10 and PM2.5 considering the new limits recommended by the WHO: 15 mu g/m(3) (PM10) and 5 mu g/m(3) (PM2.5) and (2) To simulate the behavior of these pollutants in scenarios with increased temperature (2 and 4 degrees C) using machine learning. The averages of PM2.5 and PM10 were above the limits recommended by the WHO. The scenario simulating the reduction in these pollutants below the new WHO limits would avoid more than 130 deaths and 84 hospital admissions for respiratory or cardiovascular problems. This represents a gain of 15.2 months in life expectancy and a cost of almost 160 million dollars. Regarding the simulated temperature increase, the most conservative (+ 2 degrees C) and most drastic (+ 4 degrees C) scenarios predict an increase of approximately 6.5 and 15%, respectively, in the concentrations of PM2.5 and PM10, with a progressive increase in deaths attributed to air pollution. The study shows that the increase in temperature will have impacts on air particulate matter and health outcomes. Climate change mitigation and pollution control policies must be implemented for meeting new WHO air quality standards which may have health benefits.

Automated summary

Recife is ranked as the 16th most vulnerable city to climate change and has air pollutant levels exceeding the new limits proposed by the WHO. This study evaluates the health and economic benefits of reducing PM10 and PM2.5 concentrations to the new WHO limits, and simulates the behavior of these pollutants under increased temperatures using machine learning. The results show that meeting the new limits could prevent deaths and hospital admissions, improve life expectancy, while the temperature increase is predicted to worsen air pollution and health outcomes. Mitigation and pollution control policies are crucial for meeting the WHO air quality standards and achieving health benefits.