Concentrations, spatial distribution, and human health risk assessment of asbestos fibers in ambient air of Tehran, Iran

Abstract

The aim of current research was to determine airborne asbestos fiber concentrations in the ambient air of Tehran, and to investigate their spatial distribution, seasonal variation, and human health risk assessment. For this, the sampling of the study was carried out during August 2017 and June 2018, and totally, 64 samples were taken from 8 stations along the different areas of Tehran. The concentrations of airborne asbestos fibers were determined by phase contrast microscope (PCM) and scanning electron microscopy (SEM) analyses. Spatial mapping was conducted using the inverse distance weighting (IDW) technique. The health risk assessment was done based on the detected levels of airborne asbestosis fibers. The mean concentrations of the airborne asbestos fiber were 1.9 × 10 −3 f/ml and 595 × 10 −3 f/ml based on PCM and SEM analyses, respectively. One of the effective factors on ambient level of asbestos fibers is meteorological parameters, where the maximum and minimum concentrations of asbestos fibers are related to cold and warm seasons, respectively. These differences could be due to the presence of inversions phenomenon in cold seasons in Tehran. It was observed that the excess lifetime cancer risk (ELCR) calculated for all the sampling areas are between 5.26 × 10 −5 and 5.37 × 10 −4 . Based on the EPA-suggested standards (10 −4 -10 −6 ), these values are categorized rather to moderate levels. The obtained data indicated no threat of asbestos fibers to Tehran's citizens' health.

A comprehensive study on the spatial and temporal variation of BTEX and asbestos in the northwest of Iran: Human risk assessment

“…Numerous studies showed comparable positive and negative relationships between a few meteorological parameters and the amount of asbestos fibers in the air of the studied cities; an increase in wind speed is positively correlated with the amount of asbestos fibers in the air, whereas an increase in temperature, relative humidity, and air pressure shows a negative correlation [ 55 ]. Ghorbani et al investigated traffic and urban transportation as the most important factors in the dispersion of asbestos fibers into the air of Isfahan, which is consistent with the results of asbestos fibers dispersion map for the air of the city studied in the current research [ 54 ].…”