Health risks for children exercising in an air-polluted environment can be reduced by monitoring air quality with low-cost particle sensors.

A child's body is highly sensitive to air quality, especially regarding the concentration of particulate matter (PM). Nevertheless, due to the high cost of precision instruments, measurements of PM concentrations are rarely carried out in school areas where children spend most of their daily time. This paper presents the results of PM measurements made by a validated, low-cost university air pollution measurement system operating in a rural area near schools. An assessment of children's exposure to PM during school hours (8 a.m.-6 p.m.) at different times of the year was carried out. We show that PM concentrations in the air, particularly in winter, often exceeded the alert values of 50 µg m, posing a health risk to children, especially when children exercise outside the school building. We also calculated the rate and total PM deposition in the respiratory tract during various physical activities performed in clean and polluted air. Monitoring actual PM concentrations as presented in this paper, using a low cost sensors, offer school authorities and teachers an opportunity to reduce health risks for children. This can be achieved by adjusting the duration and exercise intensity of children's outdoor physical activities according to the measured air quality.