Elucidating of potentially toxic elements contamination in topsoils around a copper smelter: Spatial distribution, partitioning and risk estimation.

Soil pollution by potentially toxic elements (PTEs) as one of the major environmental hazards is associated with metal exploration and refining acting. In this study, forty-five topsoil samples surrounding a copper smelter factory were taken and analysed using standard routine methods. The total concentration, chemical fractionation and the mobility potential of As, Cd, Cr, Cu, Pb and Zn were analysed. Additionally, the spatial distribution of PTEs, the potential ecotoxicological, and human health risks was assessed. The range of total Cu was 1478-4718 mg kg-1, reaching up to 501.5, 21.6, 118.4, 573.5 and 943.3 mg kg-1 for total contents of As, Cd, Cr, Pb and Zn, respectively. The potentially available fractions after sequential extraction reveal all studied PTE were dramatically mobile and available in the studied area (86%, 69.3%, 59.5%, 87.2%, 84% and 68% for As, Cd, Cr, Pb, Zn and Cu, respectively), reflecting that the concentration and accumulation of these elements are profoundly affected or originated by smelting activities and deposition of atmospheric emissions of the Cu smelting factory. The spatial distribution of all PTEs indicated that concentrations of these element near the smelter Cu-factory were elevated. Accordingly, the ecotoxicology status of the studied area suggests that significantly high risks are posed by the measured PTEs. Non-carcinogenic effects of As, Pb and Cu were significantly much higher than the recommended value (HI = 1), suggesting that these three PTEs could adversely impact children's health. For adults, only the HI value of As was greater than one.

Occurrence and source apportionment of polycyclic aromatic hydrocarbons (PAHs) in dust of an emerging industrial city in Iran: implications for human health.

Polycyclic aromatic hydrocarbons (PAHs) bounded to street dust are a severe environmental and human health danger. This study provides preliminary information on the abundance of PAHs in street dust from Rafsanjan city, Iran, where industrial emissions are high and data are lacking. Seventy street dust samples were collected from streets with different traffic loads. The United States Environmental Protection Agency (USEPA) Standard Methods 8270D and 3550C were used for the measurement of PAHs using GC mass spectroscopy. The total concentration of PAHs was 1443 ng g-1, with a range of 1380-1550 ng g-1. Additionally, the concentration of carcinogenic PAHs (∑carcPAHs) ranged from 729.5 to 889.4 ng g-1, with a mean value of 798.1 ng g-1. Pyrene was the most abundant PAH, with an average concentration of 257 ng g-1. Source identification analyses showed that vehicle emissions along with incomplete combustion and petroleum were the main sources of PAHs. The ecological risk status of the studied area was moderate. Spatial distribution mapping revealed that the streets around the city center and oil company had higher PAH levels than the other sectors of Rafsanjan. The results indicated that dermal contact and ingestion of contaminated particles were the most important pathways compared to inhalation. The mean incremental lifetime cancer risk (ILCR) was 1.4 × 10-3 and 1.3 × 10-3 for children and adults, respectively. This implies potentially adverse health effects in exposed individuals. The mutagenic risk for both subpopulations was approximately 18 times greater than the one recommended by USEPA. Our findings suggest that children are subjected to a higher carcinogenic and mutagenic risk of PAHs, especially dibenzo[a,h]anthracene (DahA), bounded to street dust of Rafsanjan. Our study highlights the need for the development of emission monitoring and control scenarios.

Comprehensive integrated index-based geochemistry and hydrochemical analyses of groundwater resources for multiple consumptions under coastal conditions.

The primary objective of this study was to assess the quality of groundwater in the Guilan aquifer, a principal aquifer in the north of Iran, for drinking, irrigation, and industrial purposes. In this regard, groundwater samples have taken from a database provided by the Water Resources Authority of Guilan Province, Iran's Ministry of Energy. The studied four main regions of this aquifer were Talesh, Astaneh, Lahijan, and Foomenat. Achieved results were compared with the maximum permissible limit values recommended by the World Health Organization (WHO) and Food and Agriculture Organization (FAO) water standards for drinking and agricultural purposes, respectively. Moreover, evaluation of water suitability for industrial application was determined. According to the different indices, groundwater quality is suitable for irrigation purposes in all studied areas. A Piper diagram illustrated that the most dominant water type was Ca-HCO3 in the all studied areas. This result also is consistent with results from the analysis of mineral saturation index. Accordingly, the result of water quality index (WQI) revealed that the groundwater in the Guilan aquifer could categorize from excellent to poor quality classes. However, the majority of water samples in Astaneh region mostly fall into the poor water class. The calculation of corrosiveness and scaling indices as Ryznar stability index (RSI) illustrated that a large number of the samples could be classified into aggressive and very aggressive categories. The results additionally showed that tendency to form scale based on Puckorius scaling index (PSI) was observed in some groundwater samples. Overall, the status of groundwater quality in Talesh region was noteworthy better than the other studied regions, while Astaneh region is more vulnerable with elevated contents of ions and physicochemical parameters.

Evaluation of multiple water quality indices for drinking and irrigation purposes for the Karoon river, Iran.

The main purpose of this study was to evaluate the water quality of the Karoon river, which is a main river in Iran country. For this purpose, hydrochemical analyses of a database that maintained by the Water Resources Authority of Khuzestan Province, Iran's Ministry of Energy, were carried out. These data were compared with the maximum permissible limit values recommended by World Health Organization and Food and Agriculture Organization water standards for drinking and agricultural purposes, respectively. Also in this regard, multiple indices of water quality were utilized. However, not all indices gave similar rankings for water quality. According to the USSL diagram and Kelly ratio, Karoon's water quality is not suitable for irrigation purposes due to high salinity and moderate alkalinity. However, the results of the magnesium hazard analysis suggested that water quality for irrigation is acceptable. A Piper diagram illustrated that the most dominant water types during the 15 years of the study were Na-Cl and Na-SO4. The mineral saturation index also indicated that Na-Cl is the dominant water type. The water quality for drinking purpose was evaluated using a Schoeller diagram and water quality index (WQI). According to the computed WQI ranging from 111.9 to 194.0, the Karoon's water in the Khuzestan plain can be categorized as "poor water" for drinking purposes. Based on hydrochemical characteristics, years 2000-2007 and 2008-2014 were categorized into two clusters illustrating a decline in water quality between the two time periods.

Evolution of human health risk based on EPA modeling for adults and children and pollution level of potentially toxic metals in Rafsanjan road dust: a case study in a semi-arid region, Iran.

Humans can be directly exposed to potentially toxic metals in the urban environment via inhalation, ingestion, or dermal contact of dust particles. This paper focuses on human health risk assessment of urban dust contaminated with potentially toxic metals. The levels, sources, and human health risks of nine potentially toxic metals (i.e., As, Cd, Cu, Cr, Ni, Pb, Co, Mn, and Zn) in 200 road dust samples from Rafsanjan area were investigated. Pollution level was assessed using the pollution index (PI) and geoaccumulation index (Igeo), and the health risk assessment was performed following the methodology described by the US Environmental Protection Agency. The mean concentrations of As, Cu, Pb, Cd, Cr, Ni, Zn, Co, and Mn in road dust were 105.3 ± 5.7, 791.4 ± 29.8, 123.1 ± 9.7, 28.4 ± 3.3, 3.1 ± 0.6, 18.4 ± 1.6, 252.6 ± 8.3, 16.5 ± 1.4, and 525.9 ± 21.0 mg kg-1, respectively. Thus, the concentrations of potentially toxic metals in road dust were higher than their corresponding natural background values, indicating that all studied potentially toxic metals were impacted by anthropogenic activities. The results of the current study are comparable to other studies conducted on road dust in other cities worldwide. Both of Igeo and PI decreased following order Cu > Mn > Pb > As > Zn > Cd > Ni > Cr > Co. Health risk assessment indicated that both of children and adults could be exposed to a potential increased risk of developing cancer over a lifetime from exposure to arsenic through ingestion of the dust samples. However, Pb ingestion can increase cancer risk in children.