Global air pollution and clean fuel access to anemia burden in vulnerable populations

• Exposure to PM₂.₅ is associated with an increased prevalence of anemia among women of reproductive age (15–49 years) worldwide. • PM₂.₅ levels are correlated with higher prevalence of anemia among pregnant women across the globe. • Elevated PM₂.₅ concentrations are associated to a greater prevalence of anemia in children aged 6–59 months across 122 countries. Anemia is a significant global health problem, particularly affecting women and children. This study investigates the correlation between ambient fine particulate matter (PM 2.5 ) exposure, access to clean household fuels, and anemia prevalence in vulnerable populations across 122 countries. This ecological study conducted an analysis using national-level data from 122 countries to examine the correlation between PM 2.5 (in 2 years 2016 and 2019) and the percentage of the population with access to clean cooking fuels at the same time, along with three outcomes, including anemia prevalence in women of reproductive age (15–49 years), pregnant women, and children (6–59 months). Multiple linear regression was used to identify significant factors associated with anemia in these groups. Scatter plots illustrated how anemia prevalence varied across countries with air pollution, the Human Development Index (HDI), and the Socio-Demographic Index (SDI), highlighting the interplay between environmental and socio-economic factors. The positive association was observed between PM₂.₅ and anemia prevalence among non-pregnant women (β=0.16, P=0.001). Similar positive associations were observed for pregnant women (β=0.12, P=0.008) and children under five (β=0.182, P=0.001). Conversely, there was negative association between access to clean cooking and anemia prevalence among pregnant women (β = -0.23, p ≤ 0.001). Similar negative association was observed among children under five (β = -0.108, p =0.011). Results were consistent across exposure years (2016, 2019). These findings indicate that exposure to PM₂.₅ and limited access to clean fuel are significantly associated with increased anemia prevalence among women and children worldwide, independent of socioeconomic development. These findings underscore the importance of incorporating environmental factors, particularly air pollution, into public health strategies aimed at reducing anemia, especially in low- and middle-income countries.