Iranian Journal of

Background and Objective: Heavy metals contaminations are readily bioaccumulated in aquatic systems and lead to increased concentrations in food chains, posing a serious threat to human health, water-related organisms and aquatic ecosystems. The purpose of the present study was to determine the concentration of heavy metals in surface sediments of CheshmehKile River, to evaluate environmental and ecological risk and to determine the degree of contamination of the elements studied.
Materials and Methods: In this study, 25 samples of surface sediment were collected from the CheshmehKile River. The heavy metals content of the samples was measured by inductively coupled plasma-optical emission spectrometry. According to the content of heavy metals in sediment samples, environmental and ecological risk indices were calculated. Also, river contamination was evaluated by comparing the elements studied values with the sediment quality guidelines values.
Results: The mean concentration of chromium, manganese, iron, cobalt, nickel, zinc and arsenic were 41.27, 356.35, 16756.32, 9.17, 11.87, 41.24 and 24.60 µg/g, respectively. Based on the values of the CF and I_geo indices, all of the elements, with the exception of arsenic, showed a low degree of contamination. The indices of Eⁱ_r and RI also showed the lowest ecological risk at all stations.
Conclusion: The results of this study showed that the surface sediments of CheshmeKile River in Mazandaran province were somewhat contaminated with arsenic. However, fortunately, the river sediments were of good quality from the point of view of the content of chromium, manganese, iron, cobalt, nickel and zinc.

Background and Objective: The presence of toxic mercury in fish has caused global concern, as one of the main ways of humans are exposed to it is through fish consumption. Therefore, the main goal on this research was to determine the concentration of mercury in fish and evaluate the health risk to consumers.
Materials and Methods: Samples of pike, common perch, European perch, common carp and goldfish were collected from Anzali wetland. Mercury concentration was measured using a graphite furnace atomic absorption spectrometer. Differences in mercury concentration among the species and the comparison of mercury concentration with the standards were analyzed using one-way analysis of variance and one sample t-test, respectively.
Results: The average concentrations of mercury for pike, common perch, European perch, common carp and goldfish were 59.59, 67.55, 30.45, 9.84, and 10.44 µg/kg ww, respectively. The results showed significant differences in mercury concentrations among different species. The concentrations of mercury in all samples were below the permissible limits of international standards (300 and 500 µg/kg dw), and the HQ index values were less than 1. Therefore, the results indicated no potential risk to consumer health. Additionally, the consumption of European perch, common carp and goldfish is considered safe for sensitive people (children and pregnant women).
Conclusion: In general, there was no potential concern regarding mercury exposure from consuming the studied fish species.
 

Background and Objective: Dust particles in urban environments are often contaminated with heavy metals, posing significant health risks, particularly to children. Schools are one of the environments where children are exposed to dust particles. Therefore, the aim of this study was to determine the concentration of heavy metals in the dust collected from Mashhad schools and to assess the associated health risks.
Materials and Methods: Dust samples were collected from 27 schools in the fall of 2022 using a brush.  The values of various indices were estimated, including the geoaccumulation index (Igeo), contamination factor (CF), pollution load index (PLI), enrichment index (EF), potential ecological risk index (PERI), and health risk indices such as hazard quotient (HQ) and hazard index (HI).
Results: The average concentrations of cobalt (Co), iron (Fe), calcium (Ca), aluminum (Al), lead (Pb), and barium (Ba) were 9.63, 18538.58, 84017.79, 11270.42, 32.07 and 111.56 µg/g, respectively. The Igeo values ranged from -3.69 to 1.51, while the CF values ranged from 0.16 to 4.26. The results of the pollution indices indicated that most of the studied elements were at the first level of pollution, suggesting that the degree of pollution was negligible or low. Additionally, the HQ and HI values were both less than 1.
Conclusion: Overall, the concentrations of the studied elements were not a concern, remaining at uncontaminated levels, and there was no potential health risk associated with exposure to these elements.