The present study is the first attempt to examine temporal and spatial characteristics of aerosol properties and classify their modes over Iran. The data used in this study include the records of Aerosol Optical Depth (AOD) and Angstrom Exponent (AE) from MODerate Resolution Imaging Spectroradiometer (MODIS) and Aerosol Index (AI) from the Ozone Monitoring Instrument (OMI), obtained from 2005 to 2015. The high concentration of AOD and AI values (representing high-high cluster) have been observed in the southwest and east regions, while their low concentrations (representing low-low cluster) have been found in the high mountainous areas. Based on AE values, Iran has been divided into three distinct regions, including fine, mixture, and coarse aerosol modes in each season. Results show that the maximum/minimum area under fine aerosols mode has occurred in the autumn, covering an area of 84.15% and in the spring, covering an area of 40.5%. In the case of coarse mode, the maximum/minimum area has been found in the spring, covered area=53.5% / in the Autumn covered area=12. 5%. The different aerosol modes regions strongly coincide with the topographical structure. To analyze the relation between aerosol properties and topography, Aerosol Properties Index (API) has been developed by combining OMI and MODIS datasets. API is a simple indicator, capable of showing the degree of aerosol coarseness in each pixel. There is a negative correlation between API and topography over the studied region, meaning that aerosol concentrations are high in the lowlands, but low in the highlands. However, this relation differs in various geographic regions, as Geographically Weighted Regression (GWR) model shows a higher determination coefficient in all seasons, in comparison to Ordinary Least Squares (OLS).

Wind erosion is considered a major global environmental problem. Dust storms from the migration of sand dunes can seriously damage civil, industrial, and agricultural areas and a method to stabilize these sand dunes is mulching. The present study investigates the feasibility of using organic wastes of Press mud and Dunder with clay for the production of environmentally-friendly mulches. Sandy soil from the Dejgah Region, Fars Province, has been used as bed treatment. The treatments have been prepared, using different ratios of the above mentioned materials and 250 ml of water has been added to the each mulch combination to be sprinkled on a plot of sand, 50 × 30 × 1 cm in size. The research has measured Mechanical parameters such as Compressive Resistance (CR), Abrasion Resistance (AR), and Impact Resistance (IR), created by mulches, along with Wind Erodibility (WE) of the treatments and has analyzed the resultant measured data by means of SPSS software. An increase in the fraction of organic wastes has significantly increased CR, IR, and AR values, thus reducing WE. Higher amounts of organic matter and clay increase the CR and the application of 100g Dunder plus 100g Clay has been considered the best composition of organic mulch for stabilization of sand dunes.

Although the vulnerability assessment of forest parks is used to determine the threats they face, a rapid and holistic framework has not been established well. The primary objective of this study is to adopt a framework for rapid assessment of forest parks vulnerability, examined in Lavizan forest park in Tehran (Iran) as the case study. The vulnerability assessment has been conducted, using the evaluation matrix on the basis of landscape and ecological values and threats. In this model, the most important values and threatening factors of the Lavizan forest park have been identified and assessed, based on the intensity of their effect as well as occurrence probability. Finally, this article proposes five strategies to reduce the vulnerability. Results from this research indicate that the most important values have been air purifcation, wildlife, flora and fauna species, environment regulation, mental health, and scientific resources and the most important threats have included reduction of habitat diversity, intensive exploitation of the resources, fire, woodcutting, and reduction of ecological connectivity. Based on these vulnerabilities, the most important strategies propose the use of affordance strategy formulation framework to preserve and enhance ecological and landscape values of the park.

The concentrations of Cd, Cr and Pb in soil samples and As, Cd, Cr and Pb in plant specimens were analyzed in an arid area in central Iran. Plants were categorized into desert-adapted (Haloxylon ammodendron, Atraphaxis spinosa and Artemisia persica) and non-desert species. It was found that the trace element (TE) accumulating potential of the desert species (Haloxylon ammodendron and Artemisia persica) with a mean value of 0.1 mg kg⁻¹ for Cd was significantly higher than that of the majority of the non-desert species with an average of 0.05 mg kg⁻¹. Artemisia also had a high As accumulating capability with a mean level of 0.8 mg kg⁻¹ in comparison with an average of 0.2 mg kg⁻¹ for most of the other plant species. The mean values of Cr and Pb in Haloxylon ammodendron and Artemisia persica were 5 and 3 mg kg⁻¹, respectively. Among the desert-adapted plants, Atraphaxis proved to be a species with high Cr and Pb accumulating potential, as well. The geoaccumulation index and the overall pollution scores indicated that the highest environmental risk was related to Cd. Different statistical analyses were used to study the spatial patterns of soil Cd and their connections with pollution sources. The variogram was estimated using a classical approach (weighted least squares) and was compared with that of the posterior summaries that resulted from the Bayesian technique, which lay within the 95% Bayesian credible quantile intervals (BIC) of posterior parameter distributions. The prediction of cadmium values at un-sampled locations was implemented by multi-Gaussian kriging and sequential Gaussian simulation methods. The prediction maps showed that the region most contaminated by Cd was the north-eastern part of the study area, which was linked to mining activities, while agricultural influence contributed less in this respect.

Ultraviolet radiation (UVR), with UVB and UVA as the relevant components, is a risk factor for melanoma. Complete ascertainment and registration of melanoma in Iran was conducted in five provinces (Ardabil, Golestan, Mazandaran, Gilan and Kerman) during 1996–2000. The aim of our study was to compare population-based incidence data from these provinces with rates in the United States (US) while standardizing ambient UVR.Population-based rates representing all incident cases of melanoma (1996–2000) across the five Iranian provinces were compared to rates of melanoma among white non-Hispanics in the US. Overall age-standardized rates (ASR) for Iran and the US (per 100,000 person-years adjusted to 2000 world population) and standardized rate ratios (SRR) were calculated.We measured erythemally-weighted average solar UVR exposures (with contributions from both UVB and UVA range) of the five Iranian provinces using data from NASA's Total Ozone Mapping Spectrometer and selected five US states (Kentucky, Utah, Texas, Oklahoma, and Hawaii) with matching UVR exposure to each province. Incidence rates of melanoma during 1996–2000 in each Iranian province were compared to rates among white non-Hispanics in its UVR-matched US state.The overall male and female ASRs of melanoma were 0.60 (95%CI: 0.56–0.64) and 0.46 (95%CI: 0.42–0.49), respectively, for Iran and 22.78 (95%CI: 22.42–23.14) and 16.61 (95%CI: 16.30–16.92) for the US. SRRs of melanoma comparing US to Iran were 37.97 (95%CI: 35.78–40.29) for males and 36.11 (95%CI: 33.69–38.70) for females, indicating significantly higher incidence in the US. ASRs and age-specific rates of melanoma for both genders were significantly lower in each Iranian province compared to its UVR-matched US state.The markedly lower incidence rates of melanoma in Iranian provinces with similar UVR exposures to US states underscore the need for additional comparative studies to decipher the influence of other extrinsic and intrinsic factors on the risk of this malignancy.

The aim of this study was to investigate environmental and lifestyle factors affecting exposure to PAHs in the general population in a large city of the Middle East (Tehran) by measuring urinary monohydroxy polycyclic aromatic hydrocarbons (OH-PAHs) and establishing relationships between PAHs exposure and related factors. Urine samples were collected from 222 randomly chosen subjects who were living in the urban area of Tehran, Iran. Subjects were required to complete a detailed questionnaire aimed to document their personal and sociodemographic information, activities, cooking-related appliances, smoking history/exposure, and consumed foodstuff. Identification and quantification of six OH-PAHs was carried out using a gas chromatography with mass spectrometry (GC-MS). The geometric means for 1-OHP, 1-NAP, 2-NAP, 2-FLU, 9-FLU, and 9-PHE for whole population study were 310, 1220, 3070, 530, 330, and 130 ng/g creatinine, respectively. The two naphthalene metabolites contributed on average 77% of the total concentration of six measured OH-PAHs, followed by the 2-FLU, 1-OHP, 9-FLU, and 9-PHE. The most important predictors of urinary PAHs were consumption of grilled/barbecued foods, smoking, and exposure to environmental tobacco smoking. Water pipe smoking was linked to urinary OH-PAH metabolite in a dose-response function. Residential traffic was also related with OH-PAH metabolite concentrations. Other factors including gender, age, exposure to common house insecticides, open burning, and candle burning were found to be statistically associated with the urinary levels of some OH-PAHs. High exposure to PAHs among general population in Middle Eastern large cities and its associated health implications calls for public health measures to reduce PAHs exposure.

Spatial and seasonal variations in nitrate contamination are a globally concern. While numerous studies have used δ¹⁵N-NO₃ and δ¹⁸O-NO₃ to elucidate the dominant sources of nitrate in groundwater, this approach has significant limitations due to the overlap of nitrate isotopic ranges and the occurrence of nitrate isotopic fractionation. This study quantitatively assessed the spatial and seasonal variations in the proportional contributions of nitrate sources from different land uses in the Tarom watershed in North-West Iran. To achieve this aim, orthogonal projection of the hydrochemical and isotopic dataset of the principal component analysis (PCA) as well as correlation coefficient matrix (Corr-PCA) were evaluated to reduce the dimensionality of the inter-correlated dataset. Next, a nitrate isotopic biplot accompanied with a Bayesian isotope mixing model (SIAR) were applied to specify the spatial and seasonal trends in the proportional contribution of three dominant sources of nitrate (fertilizers, animal manure and residential waste) in the watershed. Finally, in order to provide a sensitive framework for nitrate source appointment and overcome the associated limitations of dual nitrate isotope application, the integration of boron isotope (δ¹¹B) and strontium isotopic ratio (⁸⁷Sr/⁸⁶Sr) was introduced. The results revealed that the mean contribution of residential sewage increased (17%–27.5%), while the mean contribution of fertilizers decreased (28.3%–19%), from late spring to early autumn. Also, fertilizer was the highest contributor (42.1% ± 3.2) during late spring, especially in regions with more than 75% agricultural land. Meanwhile, the mean contribution of sewage was highest in early autumn (32.1% ± 2.8) in the areas with more than 20% residential land. These results were confirmed by coupled application of δ¹¹B and ⁸⁷Sr/⁸⁶Sr. This study provides a useful insight for environmental managers to verify groundwater pollution contributors and to better apply remedial solutions.

This study reports a spatiotemporal characterization of formaldehyde and acetaldehyde in the summer and winter of 2017 in the urban area of Shiraz, Iran. Sampling was fulfilled according to EPA Method TO-11 A. The inverse distance weighting (IDW) procedure was used for spatial mapping. Monte Carlo simulations were conducted to evaluate carcinogenic and non-cancer risk owing to formaldehyde and acetaldehyde exposure in 11 age groups. The average concentrations of formaldehyde/acetaldehyde in the summer and winter were 15.07/8.40 μg m⁻³ and 8.57/3.52 μg m⁻³, respectively. The formaldehyde to acetaldehyde ratios in the summer and winter were 1.80 and 2.43, respectively. The main sources of formaldehyde and acetaldehyde were photochemical generation, vehicular traffic, and biogenic emissions (e.g., coniferous and deciduous trees). The mean inhalation lifetime cancer risk (LTCR) values according to the Integrated Risk Information System (IRIS) for formaldehyde and acetaldehyde in summer and winter ranged between 7.55 × 10⁻⁶ and 9.25 × 10⁻⁵, which exceed the recommended value by US EPA. The average LTCR according to the Office of Environmental Health Hazard Assessment (OEHHA) for formaldehyde and acetaldehyde in summer and winter were between 4.82 × 10⁻⁶ and 2.58 × 10⁻⁴, which exceeds recommended values for five different age groups (Birth to <1, 1 to <2, 2 to <3, 3 to <6, and 6 to <11 years). Hazard quotients (HQs) of formaldehyde ranged between 0.04 and 4.18 for both seasons, while the HQs for acetaldehyde were limited between 0.42 and 0.97.

Although weekly consumption of fish is recommended, the presence of contaminants in seafood has raised many concerns regarding the benefits of fish intake. In the present study microplastics (MPs) and metals’ concentration in muscles of both benthic and pelagic fish species from northeast of Persian Gulf were investigated and the risk/benefit of their consumption was assessed. The results demonstrated that MPs and Hg in all species and Se in benthic species increase with size, while relationship between other metals, and fish size is not consistent. Consumption of a meal ration of 300 and < 100 g/week for adults and children, respectively, is recommended since it would provide the required essential elements with no human health risk. On the other hand, the estimated intake of MPs from fish muscles revealed that the mean intake of MPs for P. indicus, E. coioides, A. djedaba, and S. jello consumption is 555, 240, 233, and 169 items/300 g-week, respectively. Moreover, the relationship between MPs and metals in fish muscles were positive for A. djedaba, and negative for E. coioides. Considering the chemical toxicity of MPs and metals, and their good linear relationships in some species, consumption of high doses of the studied fish may pose a health threat to the consumers.

In this study we report the concentration levels of heavy metals (including Pb, Cd, Hg, Cr, Ni, Fe, Mn, Cu) in ballast water of commercial ships, entering Bushehr port for the first time in the region of the Persian Gulf. The concentration levels of Cu and Fe in all samples of the ballast water were higher compared with the coastal waters of Bushehr port. In the case of Cd, 76.47% of samples had higher concentration level compared with the coastal waters of Bushehr port. Results showed that in a long term the ballast water has the potential to change the chemical quality in marine environments and also may affect the human health and marine ecosystem where ships discharge their ballast water. Therefore, permanent monitoring as well as treatment of ballast water before discharging is crucial to keep the marine environment health.