Due to the fish are often at the top of the aquatic food chain and may accumulate large amounts of heavy metals from the water, this study was conducted to determine of Cd, Cr, Pb and Ni contents in the muscle of imported tilapia fish marketed in the city of Hamedan in 2017. In so doing, totally, 27 muscle samples from nine different brands of tilapia fish were randomly collected from the market basket of the study area. After preparation and processing the samples in the laboratory, the concentration of metals, was determined using inductively coupled plasma-optical emission spectrometer. The results showed that the mean concentrations (mg/kg) of Cd, Cr, Pb, and Ni in samples were 0.26 ± 0.09, 1.54 ± 0.15, 0.55 ± 0.11, and 0.67 ± 0.20 respectively. Also, the mean contents of Cd and Pb were higher than the maximum permissible levels (MPL) established by the World Health Organization (WHO). The computed health risk index values showed that no potential health risk for adults and children via consuming the muscle of tilapia fish at the current consumption rate for the study area. Based on the results, due to the mean contents of Cd and Pb in the muscle samples of tilapia fish were higher than the MPL, therefore, serious attention to the reduction of the discharge of hazardous substances in the aquatic ecosystems and also periodic monitoring of chemical residue particularly toxic heavy metals in the high-demand food is recommended.

The present study aims at evaluating the risk of Mutagen X (MX) (3-chloro-4-(dichloromethyl)-5-hydroxy-2 (5H)-furanone) and adverse health effects, associated with direct ingestion of chlorinated drinking water in west of Tehran, supplied by chlorinated drinking water from surface and underground water sources. For one year, MX concentrations in tap water samples has been measured for consumers in four different zones in western Tehran. It has been found that average MX concentration in the whole study area is 24.16 ng/L, with the highest concentration being in Zone 1 with a value of 38 ng/L. Also, the role of water sources, seasonal changes, and effective factors such as Total Organic Carbon (TOC) have been evaluated on MX formation. The highest of excess lifetime cancer risk (ELCR), estimated as 0.0037E-05, belongs to Zone 1, which uses surface water to supply drinking water, while the lowest can be seen in Zone 4, being 0.0021E-05. This latter zone utilizes underground water as the water source. In all zones, the highest risk of excessive cancer is related to winter, ranging from 0.0045E-5 in Zone 1 to 0.0023E-5 in Zone 4. The estimated number of cancer cases for Zones 1 to 4 have been 0.012, 0.016, 0.016, and 0.004, respectively, based on their population. The estimated average risk and the number of ELCR, caused by exposure to MX, through direct ingestion of drinking water have been 0.0030E-5 and 0.047, respectively, in the entire studied area for the duration of one year.

In the present paper, a scenario-based many-objective optimization model is developed for the spatio-temporal optimal design of reservoir water quality monitoring systems considering uncertainties. The proposed methodology is based on the concept of nonlinear interval number programming and information theory, while handling uncertainties of temperature, reservoir inflow, and inflow constituent concentration. A reference-point-based non-dominated sorting genetic algorithm (NSGA-III) is used to deal with the many-objective optimization problem. The proposed model is developed for the Karkheh reservoir system in Iran as a real-world problem. The results show excellent performance of the optimized water quality sampling locations instead of all potential ones in providing adequate information about the reservoir water quality status. The presented uncertainty-based model leads to a 55.73% reduction in the radius of the uncertain interval caused by different scenarios. Handling uncertainties in a spatio-temporal many-objective optimization problem is the main contribution of this study, yielding a reliable and robust design of a reservoir monitoring system that is less sensitive to various scenarios.

Adverse health effects of exposure to air pollution have been investigated in many previous studies. However, there is no study available on the association between maternal exposure to air pollution during pregnancy and cord blood lipid profile. This study, based on 150 mother-newborn pairs residing in Sabzevar, Iran (2018), evaluated the association of exposure to ambient air pollution as well as traffic indicators (total street length in different buffers around residential address and distance to major roads) during entire pregnancy with lipid levels cord blood lipid profile. Concentrations of PM₁₀, PM₂.₅, and PM₁ at maternal residential address were estimated using land use regression (LUR) models. We measured triglyceride (TAG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) levels and TC/HDL-C and TAG/HDL-C ratio in the cord blood samples to characterize their lipid profile. Multiple linear regression models were developed to estimate the association of exposure to air pollution and traffic indicators with cord blood lipid profile controlled for relevant covariates. Higher concentrations of PM₂.₅ and PM₁₀ were associated with higher levels of TAG, TC, HDL-C, TC/HDL-C, and TAG/HDL-C in cord blood samples. Moreover, higher concentration of PM₁ was associated with higher levels of TAG, TC and LDL-C. There was also a positive association between total street length in 100 m buffer around home and serum levels of TC, TAG, LDL-C and TC/HDL ratio (β = 3.73, 95% confidence intervals (CI): 1.76, 5.71; β = 2.75, 95% CI: 0.97, 4.53; β = 1.87, 95% CI: 0.64, 3.09; β = 0.06, 95% CI: 0.01, 0.11, respectively). However, the associations for total street length in larger buffers and distance to major roads were not statistically significant. Our findings support a relationship between exposure to air pollution during pregnancy and increase in cord blood lipid levels.

Pesticides used in agriculture are some of the most common pollutants in the world. This study aimed to investigate the effects of Organophosphorus Pesticides (OPPs) and Organochlorine Pesticides (OCPs) on the families of farmworkers in the southeast of Iran.In the present case-control study, 141 family members of farmworkers (as the case group) and 59 family members of non-farmworkers (as the controls) were recruited. Serum levels of OCPs such as α-HCH, β-HCH, γ-HCH, 2,4-DDE, 4,4-DDE, 2,4-DDT, and 4,4-DDT were determined. In addition, erythrocyte acetylcholinesterase (AChE) activity, malondialdehyde (MDA), total antioxidant capacity (TAC), protein carbonyl (PC), nitric oxide (NO) serum levels, arylesterase activity of paraoxonase 1 (PON-1), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity were determined in all participants. Furthermore, distance to farmlands, education, crops, type, and the number of consumed fruits were evaluated for each individual separately.The erythrocyte AChE activity and serum activities of GPx, SOD, and PON-1 and TAC levels were significantly decreased, whereas the concentration of MDA, PC, NO, and seven OCPs were significantly increased in the farmworkers’ families as compared to the controls. Spearman correlation and linear regression suggest that OCPs increase the oxidative stress in farmworkers’ family members. Moreover, distance, education, farming precedence, products, and ventilation had significant effects on the OCP levels and increased the odds ratio of OCP levels in farmworkers’ families.With regards to the data obtained in this study, it was revealed that OCPs as illegal pesticides and OPPs were higher than expected in the farmworkers’ family members. Furthermore, exposure to OCPs and OPPs, apart from the other effects on the body, leads to oxidative stress (OS) that may cause serious diseases in the exposed populations.

The study objective is to contemplate the effectiveness of COVID-19 on the air pollution of Indian territory from January 2020 to April 2020. We have executed data from European Space Agency (ESA) and CPCB online portal for air quality data dissemination. The Sentinel – 5 P satellite images elucidate that the Air quality of Indian territory has been improved significantly during COVID-19. Mumbai and Delhi are one of the most populated cities. These two cities have observed a substantial decrease in Nitrogen Dioxide (40–50%) compared to the same period last year. It suggests that the emergence of COVID-19 has been proved to a necessary evil as being advantageous for mitigating air pollution on Indian territory during the lock-down. The study found a significant decline in Nitrogen Dioxide in reputed states of India, i.e., Delhi and Mumbai. Moreover, a faded track of Nitrogen Dioxide can be seen at the Maritime route in the Indian Ocean. An upsurge in the environmental quality of India will also be beneficial for its neighbor countries, i.e., China, Pakistan, Iran, and Afghanistan.

Microplastic (MPs) pollution in the aquatic and terrestrial environments has caught many attentions in the scientific literatures. Currently, no information is available about MPs pollution in Caspian Sea, the largest lake in the world. This study indicates the first report on the MPs pollution in the sediments of the southern Caspian coastal zones, northern Iran. Density separation method was conducted on 17 surficial sediments. The combination of observation techniques including SEM-EDS analysis, polarized light microscopy and Raman micro-spectroscopy were used to identify MPs. The abundance and size of microplastics in the samples ranged between 25 and 330 items/kg and 250–500 μm, respectively. Fibers constituted the most common MPs shape and polystyrene (PS) and polyethylene (PE) were major polymer types in the samples. The distribution of MPs in the study area reflected a patchy and irregular spatial pattern implying that the higher MPs concentration are near mouth of permanent rivers and in the regions with higher level of the fishing and tourism activities. The results showed the wide occurrence of MPs in the sediments of the world’s largest lake which extend the knowledge on MPs pollution in the marine system. We also recommend further research on microplastics in different compartments of Caspian Sea to inform policy discussions and the development of appropriate management responses.

In this study, coral soft tissue, skeleton and zooxanthellae, as well as their ambient sediment and seawater were analyzed for polycyclic aromatic hydrocarbons (PAHs) with a special focus on perylene. Samples were collected from two different environments: the Kharg Island, which is affected by numerous anthropogenic stressors and Larak Island, which is mainly used for recreational and fishing activities and is characterized by dense vegetation. The heaviest loadings of PAHs were observed on Kharg Island, yet higher concentrations of perylene were detected on Larak Island and it was identified as the prevailing compound in this area. Pyrogenic perylene sources were prevailing on Kharg Island, whereas the perylene on Larak Island was determined to be of natural origin. After analyzing the biological samples, higher perylene concentrations were observed in zooxanthellae than in tissue and skeleton. The lowest and the highest perylene loadings were found in the tissue and skeleton of Platygyra daedalea and Porites lutea, respectively. This applies to both reefs. We found that perylene distribution in the corals and their ambient environment follows an irregular pattern, demonstrating remarkable effects from the local inputs. The lipid content in the coral tissue and the location of the coral colony were deduced to be the main factors affecting perylene distribution in corals. On Larak Island, a significant correlation between perylene loadings in sediment and corals was observed. On Kharg Island, a strong interaction between the water column and the corals was detected. The symbiotic relationship between the corals and zooxanthellae might play the most significant role in bioconcentration and bioaccumulation of perylene. Due to the insolubility of PAHs, they could be transferred through a food chain to zooxanthellae and eventually deposited in the coral bodies.

Musa estuary and its tributaries, located northwest of the Persian Gulf, host many industrial complexes, high-density ports, and urban areas along their coastal regions and are, therefore, constantly threatened by chemical contamination. The present study is the first to have investigated the surface sediments in six stations of the Musa estuary tributaries. The mean variations in BPA concentrations in the dry sediments of these stations ranged from 2.22 to 16.71 ng/g. Fairly high levels of BPA were found in Durragh station and its neighboring industrial sites. The lowest BPA level (2.22 ng/g) was observed in the station at the mouth of the Persian Gulf. Based on the EU risk-assessment system, the concentration levels of BPA in the sediments are in the low-risk range. Only in certain areas of the estuary were the sediments of moderate risk, and prolonged contact between ecological populations and them could cause toxicity in aquatic organisms.

The Persian Gulf, the most important marine ecosystem, and its islands are negatively impacted by development and pollution. Different types of pollution, especially heavy metals in these habitats, may create risks to birds, influencing reproductive performance, survival, and behaviors.Heavy metals (Cd, Pb, Cr) were analyzed in two long-lived and top food web–level sea birds, Lesser (Thalasseus bengalensis) and Greater Crested Tern (Thalasseus bergii). The research was carried out during 2018 on Nakhiloo Island, located in Dayyer-Nakhiloo Marine National Park, northeastern Persian Gulf, Iran. The nests were selected randomly, and 40 eggs of colonially-nesting terns (20 eggs T. bengalensis and 20 eggs T. bergii; a single egg per nest) were collected. The concentration of heavy metals in eggshells and egg contents was studied to investigate whether bioaccumulation varies between the eggshells and egg contents and also varies in both species. There were significant differences in the amounts of Cd between eggshell and egg content in the Greater and Lesser Crested Tern. This difference was not significant in the concentrations of Pb between the eggshell and egg content in the Tern species. Concentration of Cr did not appear to accumulate in the egg content and was below detection limit. There were significant differences in the concentrations of Cd in the eggshells and egg content between the Greater and Lesser Crested Tern. The results serve to improve understanding and to evaluate the dynamics of heavy metals in eggshells and egg content in various avian species.