Edris Hoseinzadeh - Student Research Committee, Saveh University of Medical Sciences, Saveh, Iran.
Mehrzad Ghorbani - Department of Statistics, College of Basic Sciences, Yadegar-e-Imam Khomeini (RAH) Shahr-e-Rey Branch, Islamic Azad University, Tehran, Iran.
Mahdi safari - Department of Statistics, College of Basic Sciences, Yadegar-e-Imam Khomeini (RAH) Shahr-e-Rey Branch, Islamic Azad University, Tehran, Iran.
Najmeh Ebrahimi - Student Research Committee, Saveh University of Medical Sciences, Saveh, Iran.

Introduction: High concentration of inhalable airborne particles can increase the risk of lung disease in exposed people. This study aimed to determine the respirable particulate matter (PM۵) concentration in traditional bakeries of Saveh in ۲۰۲۰. Materials and Methods: This cross-sectional descriptive study was conducted among ۲۵ bakeries where the samples were collected by cyclone and teflon filter equipped by air sampling pump. Later, the respirable particulate matter concentration was measured using gravimetric method. The collected PM۵ was scanned using a FTIR (Fourier-transform infrared spectroscopy) with regard to flour dust. In addition, size and shape of the collected PM۵ were analyzed using a scanning electron microscope (SEM). Results: Findings showed that the Lavash bakery had the highest PM۵ concentration (۹.۱۵ mg/m۳) in comparison with two other bakeries (Sangak and Barbari). However, an inverse relationship was observed between RH and particle concentration. In addition, the results demonstrated that increasing RH decreased the particle concentration, but the relationship was not significant (P = ۰.۰۵۲, Spearman's rho = -۰.۳۹۳). Furthermore, Lavash bakery had the lowest average size of PM۵ (۰.۶۳ ± ۰.۳۲ μm). However, the FTIR scans confirmed that the flour dust had the predominant amount of PM۵. Conclusion: Based on the findings, the density of respirable PM۵ has a high level in Saveh bakeries and workers  are exposed to high levels of PM.

Respirable Particulate Matter, Bakery, Indoor Air, Saveh City.