Concentration of DEHP and DnBP in surface sediments sample of Anzali wetland, Iran, were collected from 43 stations. In some locations, concentrations were exceeded a recommended environmental risk ...limit (ERL). Display omitted
•Determining the first data on distribution of phthalate esters in sediment of Iran.•Concentrations of PAEs in sediments were positively correlated with organic matter.•Concentrations of DEHP and DnBP were exceeded an environmental risk limit.•Urbanization increased the discharge of PAEs because of usage of plastic materials.
This study provides the first data on distribution of phthalate Acid esters (PAEs) in surface sediment samples taken from Anzali Wetland, Iran. These samples were collected from 43 stations. Two PAEs consist of di(2-ethylhexylphthalate) (DEHP) and di-n-butyl phthalate (DnBP) were detected and the total concentrations of these two pollutants ranged from 0.25 to 43.12, 0.12 to 19.02μgg−1 dry weight, respectively. Among all the 43 samples analyzed, no sample was found to be free of DEHP and DBP, which indicates these two phthalate esters were ubiquitous in sediments. The concentrations in the near urban regions were higher than other regions because of higher discharge of PAEs from plastic materials in urbanized areas. Concentrations of PAEs were positively correlated with total organic carbon (TOC). Generally the median concentrations of DEHP and DnBP in the sediments were 15 and 14 times higher than the ERL. These results show that the Anzali wetland are highly polluted by major PAE congeners consist of DEHP and DnBP.
The aim of this study was to determine the concentrations and degree of metals contamination (Chromium, Cadmium, Nickel and Lead) and Arsenic in the soils of the three Industrial Estates in Arak ...city, Iran. The average concentrations of Arsenic, Chromium, Cadmium, Nickel and Lead were 5.06, 1.26, 37.13, 67.84 and 60.22 mg kg
−1
, respectively. Pearson correlation indicated that Arsenic, Cadmium and Lead were mainly derived from anthropogenic inputs, and Chromium and Nickel were controlled by natural source, whereas Nickel appeared to be affected by both anthropogenic and natural sources. The geo-accumulation Index (Igeo) calculated in three industrial estates gave values indicating unpolluted to strongly polluted.
This study was conducted to determine Microcystin LR concentration in the aquatic ecosystem of the Anzali wetland in Iran. Extraction and detection of MC-LR from the water and fish samples was ...conducted by the SPE and HPLC-UV apparatus. Our results showed that among toxic cyanobacteria, Anabaena was the dominant genera during the study period. The results indicated that MC-LR content in water ranged from 0.18 to 3.02μg/L in dissolved fraction and undetectable level to 1.13μg/L in cellular fraction, in all three seasons. The results of PCA revealed that the environmental parameters including EC, Chl-a, PO43-, pH and temperature were the most effective factors influencing the MC-LR production. Results further showed the mean concentration of MC-LR in muscle and liver of silver carp ranged from 10.12 to 40.98 and from undetectable to 44.34μg/kg w.w, respectively. The mean concentration of MC-LR in northern pike was 15.18 to 35.1μg/kg w.w in muscle and undetectable to 51.91μg/kg w.w in liver samples. Our results suggest that consumption of fish harvested from the Anzali wetland seems to be unsafe for humans, based on obtained estimated daily intake values which were higher than the tolerable daily intake value recommended by WHO. In addition, bioaccumulation factor of MC-LR in edible tissues of fish was estimated based on lipid normalization. The results showed that the BAF of MC-LR in silver carp (1047±185L/kg of lipid) was lower than the northern pike (1272±185L/kg of lipid), although the difference was not significant.
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•First report concerning MC-LR concentration in a natural water body in Iran.•The EDI of MC-LR via fish consumption (trophic levels 2 & 4) was higher than the TDI.•First report on MC-LR bioaccumulation factor in fish based on lipid normalization.•The BAF of MC-LR in silver carp was lower than the northern pike.
The effect of agitation time (min) (A), initial concentration (mg/l) (B), dose of adsorbent (g/l) (C), temperature (°C) (D), and pH of solution (E), on the S/N ratio in the removal of lead (II) ...(left) and mercury (II) (right) by zinc oxide-modified mesoporous carbon CMK-3. Circles on figures indicate optimum conditions for adsorption process.
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► Using the Taguchi method, the removal of Pb(II) and Hg(II) by zinc oxide-modified CMK-3(Zn-OCMK-3) was optimized. ► The CMK-3 had high surface area which can accommodate ZnO in a spreading manner. ► The results suggest that Zn-OCMK-3 can be effectively used for remediation of Pb (97.25%) and Hg (99%). ► Removal of Pb(II) and Hg(II) were highly concentration dependent.
Using the Taguchi method, this study presents a systematic optimization approach for removal of lead (Pb) and mercury (Hg) by a nanostructure, zinc oxide-modified mesoporous carbon CMK-3 denoted as Zn-OCMK-3. CMK-3 was synthesized by using SBA-15 and then oxidized by nitric acid. The zinc oxide was loaded to the modified CMK-3 by the equilibrium adsorption of Zn(II) ions from aqueous solution followed by calcination to convert zinc nitrate to zinc oxide. The CMK-3 had porous structure and high specific surface area which can accommodate zinc oxide in a spreading manner, the zinc oxide connects to the carbon surface via oxygen atoms. The controllable factors such as agitation time, initial concentration, temperature, dose and pH of solution have been optimized. Under optimum conditions, the pollutant removal efficiency (PRE) was 97.25% for Pb(II) and 99% for Hg(II). The percentage contribution of each controllable factor was also determined. The initial concentration of pollutant is the most influential factor, and its value of percentage contribution is up to 31% and 43% for Pb and Hg, respectively. Our results show that the Zn-OCMK-3 is an effective nanoadsorbent for lead and mercury pollution remediation. Langmuir and Freundlich adsorption isotherms were used to model the equilibrium adsorption data for Pb(II) and Hg(II).
Phenolic endocrine disrupting chemicals are environmental pollutants with xenostrogen effects in wildlife and humans. The aim of this study was to determine 4-nonylphenol, Octylphenol, and Bisphenol ...A residues in various tissues of carp fish samples from Anzali wetland, Iran. 4-NP, OP, and BPA were detected with GC–MS in the muscle of fish from sampling location with maximal concentrations of 8.17, 9.67 and 5.87 μg/gdw, respectively. The highest concentrations of these compounds were found in the liver by HPLC. Since many endocrine disrupting substances were significantly lipophilic, distributing of these compounds into fish tissue has been correlated with lipid content.
Total mercury concentrations were determined in muscle tissue of Khramulia (Capoeta capoeta) captured in the Cheshme Kile and Zarrin Gol Rivers, Iran. In Cheshme Kile River, 49 fish samples were ...collected. The mean total mercury concentration in the muscles of C. capoeta from this area was 249 ng g⁻¹ dw. In Zarrin Gol River, where 62 fish samples were collected, the total mercury in muscles averaged 164 ng g⁻¹ dw. A significant difference was found between means of mercury in the rivers (p < 0.001). All samples from the two rivers had mean mercury concentrations below the maximum allowable limits for mercury set by the Food and Agriculture Organization, World Health Organization, Standardization Administration of China and Environmental Protection Agency. The results of this study indicate that the values of hazard target quotient and estimated weekly intake are low and represent a negligible risk for human health.
Introduction: The purpose of the current study was to investigate the ambient concentration levels of ground-level ozone (GLO), nitrogen dioxide, and sulfur dioxide with temporal variations and to ...determine the risk of exposure to their pollutant on public people living in this area. Materials and methods: In the present study, GLO, NOx and SO2 concentrations were monitored using an ambient analyzer during the period of April to September 2018. Results: The obtained results demonstrated that the average concentrations of SO2, NO2 and GLO in the INZ station was significantly greater than the two other evaluated stations (i.e. SHV and CMC). The corresponding values for the measured parameters in INZ station was almost 8.9, 7.2 and 11.9 times higher than those in SHV station, however, 4.8, 5.3 and 2.9 times greater than of ones in CMC station, respectively. The average values of SO2 and NO2 concentrations in the INZ varied from 97.2 to 128.1 μg/m3 in the evening hours and from 50.2 to 62.3 μg/m3 in the morning hours respectively. Also, the lowest concentration of NO2 was observed during afternoon hours when GLO showed a peak. The maximum pikes of GLO concentration were observed at 13:00 PM with 249.3 μg/m3. Results of human health risk assessment indicated acceptable risk (hazard quotient (HQ) values˂ 1) for non-carcinogenic adverse health effect. Conclusion: The findings in the present study can be useful in developing control-based strategies for primary pollutant emissions, and also GLO formation, improve air quality and reducing possible risks on human health. Policymakers should enforce the limits on the release of pollutants into the atmosphere in the study area by strengthening existing legislation.
The vertical concentration profiles and source contributions of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in respirable particle samples (PM₄) collected at 10, 100, 200 and 300-m altitude ...from the Milad Tower of Tehran, Iran during fall and winter were investigated. The average concentrations of total PAHs and total n-alkanes were 16.7 and 591 ng/m³, respectively. The positive matrix factorization (PMF) model was applied to the chemical composition and wind data to apportion the contributing sources. The five PAH source factors identified were: ‘diesel’ (56.3 % of total PAHs on average), ‘gasoline’ (15.5 %), ‘wood combustion, and incineration’ (13 %), ‘industry’ (9.2 %), and ‘road soil particle’ (6.0 %). The four n-alkane source factors identified were: ‘petrogenic’ (65 % of total n-alkanes on average), ‘mixture of petrogenic and biomass burning’ (15 %), ‘mixture of biogenic and fossil fuel’ (11.5 %), and ‘biogenic’ (8.5 %). Source contributions by wind sector were also estimated based on the wind sector factor loadings from PMF analysis. Directional dependence of sources was investigated using the conditional probability function (CPF) and directional relative strength (DRS) methods. The calm wind period was found to contribute to 4.4 % of total PAHs and 5.0 % of total n-alkanes on average. Highest average concentrations of PAHs and n-alkanes were found in the 10 and 100 m samples, reflecting the importance of contributions from local sources. Higher average concentrations in the 300 m samples compared to those in the 200 m samples may indicate contributions from long-range transport. The vertical profiles of source factors indicate the gasoline and road soil particle-associated PAHs, and the mixture from biogenic and fossil fuel source-associated n-alkanes were mostly from local emissions. The smaller average contribution of diesel-associated PAHs in the lower altitude samples also indicates that the restriction of diesel-fueled vehicle use in the central area of Tehran has been effective in reducing the PAHs concentration.
BACKGROUND: Carbaryl is widely used to control various insect pests on greenhouse cucumbers in Iran. Therefore the control of residual levels of this insecticide is highly necessary. The effects of ...the household processing such as washing, peeling and refrigeration storage, at 4 °C for 2 days on the reduction of residue levels in the plant tissues were investigated in the different groups. Samples were collected at 1 h to 14 days after application and analysed to determine the content and dissipation rate of carbaryl. Analysis was carried out by the QuEChERS method using HPLC-UV.RESULTS: Carbaryl residue in samples, which were collected post-application in different times showed a gradual and significant (P < 0.05) decrease. The half-life (t₁/₂) of carbaryl applied on cucumbers was 3.2 days. Carbaryl residues were detected in concentration ranges of 0.22-4.91 mg kg⁻¹. Also, the results indicated that the consumable safety time of carbaryl was found to be more than 14 days on cucumber.CONCLUSION: Household processing, such as washing and peeling and refrigeration storage, was effective in reducing the residue levels. Also, peeling was the most effective way to reduce the carbaryl residues of the cucumber samples. Washing and refrigerated storage also decreased carbaryl residues. Copyright
Objectives：The aim of this study was to describe the mercury concentrations in female hairdressers associated with occupational and environmental exposure through cosmetic products and amalgam ...fillings. Methods：Sixty-two hair and nail samples were collected randomly from Iranian hairdressers. Hg level determination was carried out using a LECO, AMA 254, Advanced Mercury Analyzer according to ASTM, standard No. D-6722. Results：The mean mercury levels were 1.15+-1.03μg/g and 1.82+-1.12μg/g in the hair and nail samples, respectively with a positive correlation among them (r=0.98). A significant relation was also observed between Hg levels and the number of amalgam fillings (p<0.001), use of cosmetics (p<0.001), and use of gloves (p=0.02). Conclusions：The Hg levels in about one-third of the studied samples were higher than the USEPA-recommended 1μg/g, which represents a serious health risk. Hairdressers with continuous use of cosmetics and a high number of amalgam fillings had significantly elevated mercury concentrations in their hair and nails, suggesting the importance of mercury exposure assessment in hidden, less-explored sources of Hg in the workplace.
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