جستجوی مقالات مرتبط با کلیدواژه « فلز سنگین » در نشریات گروه « پزشکی »

Groundwater contamination has major effects on human health, industrial activity, agriculture, and the environment. The present study determined the concentration of lead, cadmium, arsenic, chromium, and nickel metals in the groundwater around the landfill in Juybar City and compared them with the drinking water standards.

In this descriptive-analytical study, 12 samples were sampled from four wells for three consecutive months. The concentration of heavy elements was measured using the graphite furnace atomic absorption technique (GFAA) based on standard water and wastewater methods. Also, the hardness, temperature, pH, and total dissolved solids (TDS) parameters were measured with portable devices.

Investigations showed that the average concentration of nickel, lead, chromium, and cadmium in well water was 0.0425, 0.0071, 0.0268, and 0.0117 mg/l, respectively. The average concentration of arsenic was not observed in any sample. The average temperature, hardness, pH, and TDS were measured in the range of 20-21°C, 108.66-136.33 mg/L, 7.3-7.36, and 566.25-712.33 mg/L. Also, the correlation coefficient showed a positive correlation between the metals nickel, chromium, lead, and cadmium and the parameters of temperature, hardness, pH, and TDS, as well as with each other at a confidence level of 0.01.

The amount of arsenic, lead, chromium, pH, and hardness are acceptable in the investigated wells for drinking purposes, but the amount of cadmium, nickel, and TDS is higher than the standard.

Nowadays, trace elements are known as useful indicators for monitoring of environmental pollution caused from traffic emmissions. Therefore, this study was conducted to assess the effect of urban traffic and distance from the street side on heavy metals (Pb, Cd and Cu) concentration in surface soil and plant species of roadsides environment of city of Hamedan, west of Iran.

In this descriptive study, a total of 48 surface soil and plant samples were collected from four areas of city of Hamedan with different traffic density. After samples preparation, the concentrations of the analyzed elements in the soil and plant samples were determined using ICP-OES. Also, all statistical analyses of the obtained data were performed using SPSS software version 19.0.

Based on the results obtained, metals accumulation in soils and plants of the area with heavy traffic volume especially Basij Boulevard were higher than the other sampling areas. Also, distance from street side had been inverse relation with metals accumulation in soil and plant samples. So as the most accumulation of elements was recorded for samples collected at a distance of 5.0 m from street side.

Generally, inverse relation of metals accumulation in soil and plant samples with distance from street side might be related to vehicular emissions. Moreover, the results of this study also could be useful for managers and planners in the fields of architecture and urban design, urban land use planning, and urban traffic control managers.

Phytoremediation is a new technology for remediation of contaminated soils, this study was conducted to evaluation of efficiency of EDTA, citric acid and salicylic acid chelating agents in phytoremediation enhancing of Amaranthus caudatus and Tagetes patula for elimination of Cr(III) and Cu(II) from contaminated soils in 2018.

After soil pots contaminating by 50 and 100 (mg/kg) K2Cr2O7 and 200 and 400 (mg/kg) CuSO4 salts, and 2.5 (mmol/kg) of EDTA and citric acid (CA) and 2.0 (mmol/kg) of salicylic acid (SA) solution treating, the cultured seedlings were harvested after 60 days. Then, after seedlings digestion, Cr and Cu contents were determined using ICP-OES

Based on the results obtained, the maximum contents of Cr (mg/ kg) in cultivated soil, root and stem samples of A. caudatus were 2.40, 5.18 and 1.86 were found in the SA, EDTA and EDTA treatments, respectively and in T. patula with 2.74, 6.00 and 1.30 were found to be in the SA, EDTA and EDTA treatments, respectively. Also, the maximum contents of Cu (mg/kg) in cultivated soil, root and stem samples of A. caudatus with 6.74, 3.77 and 3.34 were found to be in the SA, SA and EDTA treatments, respectively and in T. patula with 6.65, 3.45 and 9.50 were found to be in the SA, EDTA and EDTA treatments, respectively. On the other hand, translocation (TF) and bioconcentration (BCF) factors of A. caudatus both were greater than 1 in soils with 100 mg/kg added K2Cr2O7 containing CA, which indicates that this species can be known as hyperaccumulator of Cr

In conclusion, concerning to the considerable role of organic acids in soil refining electrokinetic and phytoremediation efficiency enhancing, using of these soil amendment agents is recommended to cleanup of contaminated soil with heavy metals

The presence of heavy metals in the environment and especially bioaccumulatioin of these compounds in tissues of aquatic organisms could constitute be a hazard to food security and public health. Therefore, this study was conducted to analysis of As, Pb and Cu contents in muscle tissue of Oncorhynchus mykiss and Barbus barbus captured from the Sirvan River, Kurdistan in 2019.

In this descriptive cross-sectional study, a total of 30 fish samples were collected randomizelly from five sampling stations along the Sirvan River. After samples preparation, As, Pb and Cu concentrations were determined using ICP–OES. Also, all statistical analyses of the obtained data were performed using SPSS software.

The results showed that the mean concentrations of As, Pb and Cu (µg/g, wet weight) in muscle tissue of Oncorhynchus mykiss were 0.022, 0.034, and 0.078, respectively, while in muscle tissue of Barbus barbus were found to be 0.018, 0.012 and 0.042, respectively. Also, the mean contents of all the analyzed elements were lower than maximum permissible concentration (MPC) established by FAO/WHO, ATSDR, FDA and EU.

Although at the time of this research the contribution to the total body burden of the analyzed elements can be considered as negligibly small, mismanagement of land uses around the Sirvan River could lead to the entry of several kinds of pollutants such as pesticides and potentially toxic elements into the water body. Consequently, adverse health effects could be occured for local consumers through ingestion of fishes with high accumulated heavy metals in their tissues.

Zinc is one of the heavy metals in aquatic ecosystems. Currently, nanotechnology has made significant progress in various industries, in the present study, the toxicity of nano-zinc oxide on the blood indices of Capoeta capoeta gracilis (Capoeta) was investigated.

This research was conducted with concentrations of 0, 5, 20, 100 and 400 mg/L of nano-zinc oxide (Nano-ZnO) for 14 days on 70 Capoeta with a mean weight of 20±5 grams. After the experiment, blood samples were taken from the Capoeta and various blood indices were measured including leukocytes, lymphocytes, neutrophils, eosinophils, erythrocytes, hemoglobin, hematocrit, MCV, MCH and MCHC.  

All blood erythrocyte indices in Capoeta showed significant changes, but leukocyte indices did not change. Also, with the increase of nano-zinc oxide in different treatments, the number of red blood cells, hemoglobin and hematocrit decreased and the number of white blood cells increased in Capoeta.  

With rising the concentration of nano-zinc oxide, the level of hematological adverse effects increased and the concentration of 100 mg/l has the most adverse effects in Capoeta. Nano-zinc oxide causes anemia and disrupts Capoeta's immune system, which may be due to its destructive effects on hematopoietic organs such as the liver and kidney.

In the present study, an environmentally friendly microextraction of nickel based on solid-phase method coupled to flame atomic absorption spectrophotometry was investigated. Due to elimination of organic solvents in this method, it can be used as a green technique to extract and reduce the detection limit of nickel in water samples.

By adding 0.06 g sodium borohydride (NaBH4) to 100 ml of the solution containing Fe (II) ions with concentration of 12 mg/l and nickel, these ions were converted to zero-valent particles. The nickel revived particles were trapped in the iron microparticles and deposited with them. After that, the solid phase produced was dissolved in 200 µl  of hydrochloric acid (HCl) 6N and the nickel concentration was measured using atomic absorption method. To optimize the process, effect (1 to 8), the amount of potassium hydrogen phthalate (KHP) (0.02-0.30), Fe (II) concentration (2.20-5.00 mg/l), NaBH4 (0.20-0.01 g), time (0.5-15.00 minutes), and temperature (20° -80°  C) were investigated. In addition, the effect of interfering ions was evaluated. Finally, the figures of merit were calculated, and the function of the method was investigated in the real water samples.

According to the performed optimization, pH = 4.5, NaBH4 = 0.06 g, Fe (II) = 2.5 mg/l, KHP = 0.08 g, time= 4 minutes, temperature = 50° C , and sample size = 100 ml were the optimum conditions. Besides, the concentration factor of 410, the detection limit of 0.3 ng/ml, and relative standard deviation (RSD) of 2.7% were obtained.

Due to the low detection limit and the elimination of organic solvents in nickel microextraction, this method can be a suitable method for determining trace amount of nickel with high efficiency. The low detection limit is due to the high concentration factor, which is significantly higher than the other microextraction methods.

Nowadays, soil contamination with heavy metals is among the main world concern, and therefore, special attention to protecting soil quality is vital. In this regard, the decrease of bioavailability and mobility of these elements in the soil are very important to control their toxicity and their acute and chronic effects. Therefore, this study was conducted to investigate the efficiency of natural zeolite for the immobilization/stabilization of lead and cadmium in a contaminated soil sample.

In this study, first, the control and experimental (containing 5% of natural zeolite) soil treatments were contaminated with 150, 500 and 1500 mg/kg of Pb and 10, 30 and 100 mg/kg of Cd. Then the contents of Pb and Cd in the soil samples were determined in various fractions (i.e. exchangeable and acid-soluble fraction (F1), the reducible fraction (F2), the oxidisable fraction (F3) and the residual fraction (F4)) of both soil treatments were extracted using the BCR sequential extraction procedure and finally, the mobility rates of the elements were computed at different incubation periods (i.e. 1, 7, 14, 28 and 56 days).

The results showed that the mobility of Pb in the experimental treatment containing 150, 500 and 1500 mg/kg added lead was decreased 51%, 23% and 15% at 56th day of incubation compared to the control treatment. While, the mobility of Cd in the experimental treatment containing 10, 30 and 100 mg/kg added cadmium was decreased 12%, 9% and 5% at the 56th day of incubation compared to the control treatment.

Based on the results obtained, although with increasing in the added amounts of Pb and Cd in the soil the efficiency of natural zeolite as an amendment agent in the immobilization and solidification of these elements was reduced, natural zeolite can be used for chemical fixation of heavy metal- contaminated soils due to its acceptable efficiency in heavy metal uptake, reasonable price, abundance and minimal adverse environmental impact.

Traditional pastries are the favorite common food items of people at all ages, especially children who consume them in large amounts. Since raw materials and manufacturing processes may be the main sources of contamination of foodstuffs by hazardous compounds particularly toxic heavy metals, this study was conducted to health risk assessment of Pb, Cd, Cr and Cu through consumption of two famous traditional pastries (i.e. "Nan-e Berenji" and "Kak") which marketed in city of Kermanshah in 2019.

After the purchase of 21 samples of each pastry of seven popular brands and acid digestion of the samples according to standard methods, the content of studied elements was determined using inductively coupled plasma- optical emission spectrometer (ICP-OES) in 3 replicates. Also, all statistical analyses were performed using the SPSS software.

Based on the results the mean contents of Pb, Cd, Cr and Cu (mg/kg) in Nan-e Berenji samples were 0.770, 0.034, 1.21 and 1.14, respectively, while the mean contents of elements in Kak samples were 0.200 for Pb, 0.035 for Cd, 1.02 for Cr and 1.23 mg/kg for Cu. Besides, the results obtained showed that TTHQ values were 2.57 ⨯ 10-2 and 5.29 ⨯ 10-3 for children and adults, respectively, who consuming Nan-e Berenji and were 1.1 ⨯ 10-2 and also 2.33 ⨯ 10-3, respectively, for children and adults who consuming Kak. Also, the mean contents of Pb in Nan-e Berenji samples were higher than the WHO maximum permissible limits (MPL). Besides, THQ values were within the safe limits (THQ < 1), and there is no potential health risk for adults and children via the consumption of analyzed traditional pastries. According to the results of the current study, the controlled consumption of traditional pastries under the current consumption rate hasnchr('39')t an adverse effect on the consumerchr('39')s health. While, the mean contents of Pb in Nan-e Berenji samples were higher than the MPL, and due to the persistent and bioaccumulation potential of heavy metals in the body tissues, regular periodic monitoring of the content of toxic metals in popular foodstuffs for maintaining human health and achieve food security is recommended.

Bioaccumulation Capacity of Heavy metals in aquatic bodies can do a serious threat to food security and public health. Therefore, in this study, the amount of lead, cadmium and copper in edible tissues of hydrothermal fish in Alborz province was determined in 2017.

Twenty-one carp fish of three species were randomly selected from the Mahmoudi fishery, which supplies the Alborz hydrothermal fish market, and after acidic digestion of the specimens, the concentration of lead, cadmium and copper was determined by Atomic absorption device.

The mean concentration of lead, cadmium and copper in wild carp, amur and phytophagus in ppb and for cadmium was measured. Highest amount of lead in  Hypophthalmichthys molitrix, Cadmium in Ctenopharyngodon idella &Copper in Hypophthalmichthys molitrix was observed.Statistical comparison of the mean concentrations of the Heavy metals with the guidelines of the United Nations Food and Agriculture Organization showed that the mean concentration of all Heavy metals was lower than the permissible limit.  

Although currently the mean concentrations of the evaluated Heavy metals in the carp edible tissue of Alborz province are not exceeded, but lack of proper management of the water supply resources of fish ponds can lead to the entry of pollutants, including heavy metals, into the fish farm.In resident aquaculture tissues, endangering the health of consumers.