Public responses about air quality in the world's ten most populous countries.

Understanding how people view and react to outdoor air quality is crucial to effectively managing and responding to air pollution, which is a major threat to global public health. Using a quota sample of 10,618 respondents from 1,372 localities across the world's ten most populous countries (Bangladesh, Brazil, China, Indonesia, India, Mexico, Nigeria, Pakistan, Russia, and the United States), we assessed the association between exposure to fine particulate matter with diameter ≤ 2.5 micrometers (PM2.5) and people's knowledge, attitudes, perceptions, practices, and concern about air quality. Overall, we find an inverse association between air pollution exposure and knowledge about air quality, and a positive association between air pollution exposure, practices, attitudes, and concern about air quality. We also identified significant interactions with demographic characteristics such as age, sex, education, place of residence, political ideology, and marital, employment, or smoking status, which can inform targeted interventions among vulnerable populations.