The concentration of particulate matters in mechanically ventilated school classroom during haze episode in Kuala Lumpur City Centre

Good indoor air quality (IAQ) is essential to ensure students’ and teachers’ improved performance and productivity. This study aimed to investigate particulate matter (PM) concentration with different sizes in a classroom during haze episode and to evaluate the health effect of air pollution during haze to the school student in Malaysia. The particulate matter concentration with aerodynamic diameter size less than 10 µm (PM10) was collected for 8 h using a low volume air sampler (LVS) equipped with quartz filter paper. The trace metals element (Pb, Cd, Co, Ni, Cr, Mn, As and Cu) in PM10 was analysed using inductively coupled plasma mass spectrometry (ICP-MS). Simultaneously, PM concentration in real time at differences sizes (PM10, PM2.5 and PM1) was also collected using Grimm aerosol spectrometer with 1-min interval. A questionnaire survey on school children’s health condition and the lung function test using spirometry were also performed. The results show that there was no significant difference in PM10 concentration during haze (95 ± 25 μg m−3). The dominant trace metal concentrations in PM10 were Mn and Cr both during haze. The mean concentrations of continuous monitoring of PM10, PM2.5 and PM1 during haze event were 85 ± 14 μg m−3, 68 ± 16 μg m−3 and 61 ± 16 μg m−3. The mean forced expiratory volume in the first second (FEV1) and the mean forced vital capacity (FVC) value during haze were 97.7% and 91.8%. The health risk assessment of school children on trace metals in PM10 via inhalation was higher than the acceptable value with a total hazard quotient (HQ) more than 1.0 for both hazes. For carcinogenic elements, the excess lifetime cancer risk (ELCR) was higher than the acceptable limit for haze event with a value of 3.4XE-05. This study found that the impact of haze pollution on indoor PM10 concentration was relatively low; however, there was still a high exposure of school children to the carcinogenic and non-carcinogenic elements during haze event.