Projected health benefits of air pollution reductions in a Swedish population

A large part of the Swedish population is exposed to higher levels of air pollution than the health-centered air quality guidelines recommended by the World Health Organization (WHO).

The aim of the study was to illustrate the potential health benefits of cleaner air in Sweden by conducting a comprehensive health impact assessment, using a population sample of 100,000 individuals representing the country's demographics.

Exposure-response functions for various health outcomes were derived from epidemiological literature, mainly from systematic reviews and low-exposure settings. Two hypothetical scenarios were studied: a 1 µg/m³ decrease in particulate matter with an aerodynamic diameter <2.5µm (PM_2.5) and nitrogen dioxide (NO₂), and a reduction in PM_2.5 or NO₂ from average exposure corresponding to Sweden's Clean Air objectives to WHO's air quality guidelines.

The findings demonstrated that even a modest decrease in air pollution concentrations can yield significant health benefits. For example, reducing PM_2.5 by 1 µg/m³ was projected to correspond to a 1% to 2% decrease in mortality, a 2% reduction in myocardial infarction cases, a 4% decrease in stroke incidence, a 2% decline in chronic obstructive pulmonary disease, and a 1% decreases in lung cancer and type 2 diabetes annually. Moreover, this reduction is estimated to lower childhood asthma cases, incidences of hypertension during pregnancy, and premature births by 3%, 3% and 2%, respectively, each year.

The results highlighted that even minor enhancements in air quality would lead to substantial improvements in public health.