Exposure and biomonitoring of PAHs in indoor air at the urban residential area of Iran: Exposure levels and affecting factors.

The concentration of polycyclic aromatic hydrocarbons (PAHs) in the air inside residential houses in Iran along with measuring the amount of 1-OHpyrene metabolite in the urine of the participants in the study was investigated by gas chromatography-mass spectrometry (GC-MS). Demographic characteristics (including age, gender, and body composition), equipment affecting air quality, and wealth index were also investigated. The mean ± standard error (SE) concentration of particulate matter 10 (PM10) and ∑PAHs in the indoor environment was 43.2 ± 1.98 and 1.26 ± 0.15 µg/m3, respectively. The highest concentration of PAHs in the indoor environment in the gaseous and particulate phase related to Naphthalene was 1.1 ± 0.16 µg/m3 and the lowest was 0.01 ± 0. 0.001 µg/m3 Pyrene, while the most frequent compounds in the gas and particle phase were related to low molecular weight hydrocarbons. 30% of the samples in the indoor environment have BaP levels higher than the standards provided by WHO guidelines. 68% of low molecular weight hydrocarbons were in the gas phase and 73 and 75% of medium and high molecular weight hydrocarbons were in the particle phase. There was a significant relationship between the concentration of some PAH compounds with windows, evaporative coolers, printers, and copiers (p < 0.05). The concentration of PAHs in houses with low economic status was higher than in houses with higher economic status. The average concentration of 1-hydroxypyrene metabolite in the urine of people was 7.10 ± 0.76 µg/L, the concentration of this metabolite was higher in men than in women, and there was a direct relationship between the amount of this metabolite in urine and the amount of some hydrocarbon compounds in the air, PM10, visceral fat and body fat. This relationship was significant for age (p = 0.01). The concentration of hydrocarbons in the indoor environment has been above the standard in a significant number of non-smoking indoor environments, and the risk assessment of these compounds can be significant. Also, various factors have influenced the amount of these compounds in the indoor air, and paying attention to them can be effective in reducing these hydrocarbons in the air.

Reference values for metal(loid)s concentrations in the urine samples of healthy Iranian adults: Results from the first nationally representative human biomonitoring study.

BACKGROUND: This study measured the concentrations of arsenic (As), aluminum (Al), cadmium (Cd), chromium (Cr), mercury (Hg), nickel (Ni), and lead (Pb) in the urine samples of the Iranian adult population. METHODS: This nationally representative study was conducted on 490 participants in six provinces of Iran who were selected based on the clustering method. Participants included healthy Iranian adults aged above 25 years without a history of illness and non-smokers. Fasting urine sampling, body composition, and demographic measurements were performed for each participant. Urine samples were analyzed by acid digesting method using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The analysis included descriptive statistics and multiple linear regression using Python programming language. RESULTS: The geometrical mean (with corresponding reference values, µg/l) concentrations of metal(loid)s in urine for women, men, and both were 198.2 (625.3), 163.5 (486.1), and 192.5(570.4) for Al, 15.6(51.7), 28.8(71.1), and 21.9 (61.64) for As, 18.5(55.2), 20.7(56.5), and 19.22(55.75) for Pb, 17.9(57.6), 17.9 (53.9), and 17.9(56) for Ni, 13.95(47.5), 20.3(62.2) and 16(51.6) for Cr, 3.5(12.2), 2.9(11.5), and 3.3(12) for Hg, 0.74(2.7), 0.95 (3.6), and 0.81(3.1) for Cd. There was a direct relationship between the concentration of metal(loid)s and demographic indicators and body composition (P<0.05). Moreover, there was a direct relationship between the concentration of As, Cr, Hg, Ni, and Pb with age and wealth index (P<0.05). CONCLUSIONS: The concentrations found could be used as the reference range for As, Al, Cd, Cr, Hg, Ni, and Pb for human biomonitoring studies on the Iranian adult population.