Nitrogen dioxide exposure and health risk assessments of students in elementary schools in the vicinities of an industrial estate, located in Rayong Province, Thailand

Abstract

Exposure to nitrogen dioxide (NO2) poses a danger to the health of many children all over the world especially children that attend schools in the vicinities of traffic roads and industries. This research study aims to assess the impacts of NO2 exposure on the health of the students. NO2 samples were collected by tube-type passive samplers. Moreover, the investigation of indoor NO2 exposure of students was associated with physical human health by using multiple logistic regressions. The results revealed that the indoor and outdoor NO2 concentrations in elementary schools were 9.0 ± 4.4 to 16.7 ± 2.7 μg/m3 and 8.2 ± 2.1 to 17.7 ± 6.7 μg/m3, respectively. However, indoor and outdoor values of NO2 were lower than the WHO standard of 40 μg/m3. Non-carcinogenic risk assessments of NO2 were carried out to help assess the health risks of students. It was found that the HQ of all those who studied in schools was less than 1, indicating no health risks. However, NO2 in classrooms can cause eye irritation (p-value = 0.007), pink eye/ allergic conjunctivitis (p-value = 0.012), runny nose (p-value = 0.020), sore throat (p-value = 0.038), wheeze (p-value = 0.022) and cough (p-value = 0.035). Therefore, children who spend time in classrooms close to heavy traffic and petrochemical plants might find themselves exposed to increased health risks.