Size distribution and chemical composition of indoor and outdoor particles in lab building

Introduction: Exposure to toxic components in indoor PM is associated with a wide spectrum of adverse respiratory and cardiovascular health effects. The fine PM pollution in ambient air is currently a major health concern in Iran and is driving increasing research interest. Due to air pollution in Tehran met-ropolitan, it is necessary to study the concentration and size distribution of particles inside and outside the building. Materials and methods: Hence, for this study, concentration and size distribution of particles matter was calculated with diameters of PM≤0.4, PM0.4-0.7, PM0.7-1.1, PM1.1-2.1, PM2.1-3.3, PM3.3-4.7, PM4.7-7, PM7-11, PM≥11 and TSP during two seasons in the lab building in the Tehran. Measurements on the aerodynamic size of atmospheric aerosols carried with Anderson type 1-ACFM Cascade Impactor with six-stage. The length of each collection period was about 24 h. Results: The results show that the effect of outdoor air pollution on the con-centration of particles in the indoor environment is significant. According to these results, the lowest value is for particles with a diameter greater than 11 µm. the highest value of this ratio is dedicated to PM≤0.4 and with the increase of the aerodynamic diameter of the particles, the I/O decreases as well. A similar trend was recorded for concentration of TSP. The highest difference in the concentration of TSP in indoor and outdoor was 60.25 and 188.36 µg/ m3, respectively. Conclusion: This effect is due to factors such as the lack of standard ventilation, old doors and windows and the life of the building.