Background Air pollution is a major public health threat and has been linked to various adverse health effects including respiratory and cardiovascular diseases. Fine particulate matter (PM2.5) and coarse particulate matter (PM10) are two major components of air pollution that are significant contributors to these health outcomes. With the advent of low-cost sensors, accurate measurement of exposure has become possible, allowing for better assessment of the impact of air pollution exposure on human health. Methods To investigate the association between air pollution exposure and illnesses resulting in hospital visits, IoT sensors were deployed in Ulaanbaatar, Mongolia, to measure PM2.5 and PM10 levels from 2018-2021. Health data was obtained from the Mongolian National Center for Public Health. Multivariable logistic regression models were used to estimate overall odds ratios for the associations between daily PM2.5 and PM10 exposure and the occurrence of illnesses, adjusting for age and sex. Results The unadjusted odds ratio for the association between PM10 exposure and acute respiratory illnesses was 1.3, while the unadjusted odds ratio for PM2.5 exposure was 1.2; decreasing to 1.2 and 1.1 respectively after adjusting for age and sex (p < 0.05). These findings are consistent with previous studies and highlight the significant impact of air pollution on the occurrence of acute respiratory illnesses. The use of IoT sensors allowed for accurate assessment of air pollution exposure in the study population. Conclusions This study provides further evidence of the detrimental effects of air pollution on human health, particularly on the occurrence of acute respiratory illnesses. These findings highlight the importance of continued efforts to reduce air pollution levels. Accurate measurement of exposure rates using IoT sensors can aid in identifying and addressing sources of air pollution to improve the quality of life for individuals and communities affected by this health threat.< Réduire