Exposure assessment of metal(loids) in indoor air and biomonitoring in six urban residential areas in Iran.

Exposure to metal(loid)s can cause adverse health effects. This study evaluated the concentrations of aluminum, arsenic, cadmium, chromium, mercury, nickel, and lead in particulate matter <10 µm (PM10) and in the urine of 100 participants from urban residential areas in Iran. A total of 100 residential buildings (one adult from each household) in six cities across Iran were recruited for this study. The levels of metal(loid)s in PM10 and the urine of participants were measured using acid digestion followed by inductively coupled plasma mass spectrometry (ICP-MS). The average (±SE) PM10 concentration in the buildings was 51.7 ± 3.46 µg/m3. Aluminum and cadmium had the highest and lowest concentrations among the metal(loid)s, averaging 3.74 ± 1.26 µg/m3 and 0.01 ± 0.001 µg/m3, respectively. In 85 % of the samples, the concentration of metal(loid)s in indoor air exceeded WHO air quality standards. Cadmium and lead had the highest and lowest numbers of indoor air samples exceeding the recommended standards, respectively. A significant correlation was found between the concentration of metal(loid)s in urine samples and indoor PM10 levels, as well as the wealth index of participants. There was also a significant direct relationship between the concentrations of nickel, arsenic, lead, and mercury in urine and the age of participants. Factors such as building location, type of cooling systems, use of printers at home, and natural ventilation influenced the concentration and types of metal(loid)s in the indoor air.

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.

Assessing the role of drought in dust storm formation in the Tigris and Euphrates basin.

Drought is a common meteorological phenomenon and one of the world's most costly natural hazards. A large part of the Tigris and Euphrates basin (TEB) is located in the arid and semi-arid regions of western Asia and suffers from drought. Drought has many destructive effects on the environment and human societies, among which the formation of dust storms, is a major global challenge. This study aims to figure out the role of different types of drought on dust storm formation in the TEB. Standardized precipitation index (SPI), Tasseled Cap greenness index, and surface water area changes based on time series of satellite remote sensing data were considered as proxies to investigate meteorological, agricultural, and hydrological droughts, respectively. Our results show that the continuation of the 5-month and 27-month meteorological droughts are followed by agricultural and hydrological droughts, respectively. In recent decades, the TEB has experienced two prominent drought periods in 2008-2012 and 2021-2022, resulting in a 214 % and 200 % increase in dust events, respectively, compared to the 23-year (2000-2022) average. Overall, 84 %, 10 %, and 6 % of the TEB dust events can be attributed to meteorological, agricultural, and hydrological droughts, respectively.

Ecological potential assessment and land use area estimation of agricultural lands based on multi-time images of Sentinel-2 using ANP-WLC and GIS in Bastam, Iran.

The use of land-based ecological potential is a key management factor in achieving sustainable development and conserving soil and water resources. The purpose of this study is to use multi-time images of Sentinel-2 to determine the area of agricultural lands and evaluate their ecological potential in Bastam, Semnan Province, Iran. Therefore, in the first step, the most common agricultural lands (including apricot and grape orchards), field crops (including wheat and forage maize), and their phenological period were determined. Then, the information was classified using, namely support vector machine, maximum likelihood, and minimum distance. In the next step, soil, topography, and climate data were extracted according to expert opinions and the analysis of the basin's natural potential. The ecological evaluation models of the region were applied to homogeneous units, and after calculating the ecological potential index by the integrated ANP-WLC model, the ecological potential map was generated. The results of the land use classification showed that the support vector machine model and the minimum distance, respectively, had the best and worst performance with kappa coefficient of 0.82 and 0.61. The highest area of cultivated lands (3423 hectares) was estimated for wheat and the lowest (738 hectares) for forage maize. Moreover, the results of the ecological potential evaluation showed that 60% of apricot orchards, and 40.19% of the wheat fields, were in the class of good ecological potential. Overall, 2290 hectares were in the poor class, and 4030 hectares in the excellent class in terms of ecological potential.