Ambient (outdoor) air pollution comprising fine particulate matter like PM_2.5和家庭空气污染(HAP)引起的by inefficient cooking methods using fuels like biomass, kerosene or coal, together cause up to 7 million premature deaths every year. Yet, there is limited data on the health effects of ambient air pollution from lower-middle-income countries, specifically on young adults following their lung peak growth. According to Otavio Ranzani, ISGlobal researcher and first author of the study: "There has been a lot of research on air pollution and its effects on the lung function of children. But this is one of the first studies looking at the population group of young adults in a low- and middle-income country setting."

Data on 1,044 participants (within the age group of 20-26 years) were collected from the Andhra Pradesh Children and Parent Study (APCAPS) cohort (2010-2012), situated in 28 villages in the peri-urban area of Hyderabad city. The researchers measured lung function with: i) FEV1 (forced expiratory volume in the first second), an indicator for resistance of airflow through the respiratory tract while forced breathing; and ii) FVC (forced vital capacity), an indicator of lung capacity. Factors like sex, health behaviours, and socioeconomic factors were identified and adjusted during the analysis.

Results showed that household air pollution (measured by use of biomass fuel) was consistently associated with decreased lung function. This effect on lung function was especially prominent in participants who lived in households that used unvented biomass stoves. The average decrease of 142 ml in lung capacity due to household air pollution was magnified to 211 ml for those who used unvented biomass stoves. The analysis also revealed a link between ambient PM_2.5with decreased lung function, but these results were less conclusive. Overall, these findings suggest that reducing levels of exposure to ambient PM_2.5and household air pollution might be effective in improving lung function in adulthood.

Some 2.6 billion people continue to use biomass for cooking and there is little research on how this affects lung function trajectories during childhood. This study provides a glimpse of the cumulative impact on respiratory health by focusing on young adults who recently attained their maximum lung function. "This cross-sectional study opens the doors for further longitudinal research on the effect of air pollution on lung development, especially in low- and middle-income country settings where individuals are commonly exposed to both high levels of ambient and household air pollution," concludes Cathryn Tonne, ISGlobal researcher and senior author of the study.