Serum concentration of polychlorinated biphenyls and the risk of type 2 diabetes: a 10-year follow-up historical cohort study.

This study investigated the association between serum concentrations of Polychlorinated Biphenyls (PCBs) and the risk of type 2 diabetes within the general population. A ten-year follow-up historical cohort study was conducted during 2009-2019 as part of the Bushehr MONICA cohort study in Iran. Of 893 non-diabetes participants at base line, 181 individuals were included in the study. The concentration of nine PCB congeners was measured in individuals' serum samples at baseline, and the risk of type 2 diabetes was determined based on fasting blood sugar at the end of follow-up. Multiple logistic regression models were used to assess the study outcomes after adjusting for covariates. This study included 59 diabetes individuals (32.6%; mean [SD] age: 58.64 [8.05]) and 122 non-diabetes individuals (67.4%; mean [SD] age: 52.75 [8.68]). Multivariable analysis revealed that a one-tertile increase (increasing from 33rd centile to 67th centile) in Σ non-dioxin-like-PCBs (OR 2.749, 95% CI 1.066-7.089), Σ dioxin-like-PCBs (OR 4.842, 95% CI 1.911-12.269), and Σ PCBs (OR 2.887, 95% CI 1.120-7.441) significantly associated with an increased risk of type 2 diabetes. The strongest association was obtained for dioxin-like PCBs. The results highlight a significant correlation between PCB exposure and an increased risk of type 2 diabetes. The evidence suggests that additional epidemiological studies are necessary to clarify the link between PCBs and diabetes.

Pesticide residues in drinking water treatment plants and human health risk assessment: a case study from Northern Iran.

These days, the presence of pesticide residues in drinking water sources is a serious concern. In drinking water treatment plants (DWTPs), various methods have been proposed to remove pesticide residues. This study was designed with the objectives of monitoring the occurrence and seasonal variations of pesticides in the output of drinking water treatment plants in two Northern provinces of Iran, Gilan and Golestan, and identifying their human health risks. Seventeen pesticide residues from different chemical structures were determined by using a gas chromatograph-mass spectrometer (GC-MS). The results showed that only Alachlor, Diazinon, Fenitrothion, Malathion, and Chlorpyrifos were detected. The pesticide concentrations ranged from ND to 405.3 ng/L and were higher in the first half-year period. The total non-carcinogenic human health risks was in safe range for infants, children, and adults (HI < 1). The carcinogenic human health risks of Alachlor for infants, children, and adults were in the range of 4.3 × 10-7 to 1.3 × 10-6, 2.0 × 10-7 to 9.6 × 10-7, and 1.1 × 10-7 to 5.5 × 10-7, respectively. These values do not pose health risks for adults and children, but may present a possible cancer risk for infants in two DWTPs of Golestan. In conclusion, considering the possibility of exposure to these pesticides through other routes, simultaneously, it is suggested to carry out a study that examines the level of risk by considering all exposure routes. We also propose stricter regulations for the sale and use of pesticides in Iran.

Exposure sources of polychlorinated biphenyls (PCBs) and health risk assessment: a systematic review in Iran.

This systematic review aims to identify the sources of exposure to polychlorinated biphenyls (PCBs), portioning, and human health risk assessment in Iran. The literature was searched in the international databases of Web of Science, PubMed, Scopus, Google Scholar, and the national databases of SID and MagIran up to November 14, 2020. Among all 153 articles, 21 eligible papers were identified. Among them, only one article was related to drinking water, the rest was related to food and soil, and no article was found on ambient air. The corrected portion of each exposure source was determined to be 90% for food, 9% for water, and 1% for air. The total hazard quotient (HQ) was determined to be within an unsafe range, and the total excess lifetime cancer risk (ELCR) was determined to be at a high risk of oral carcinogenesis. It is suggested that a comprehensive study be conducted in a specific period for all sources of exposure in all counties of Iran. Moreover, it is recommended that the policymakers set national standards for this pollutant in near future in some sources of exposure (e.g., drinking water) which have no standards in Iran.

Presence of heavy metals in drinking water resources of Iran: a systematic review and meta-analysis.

Water quality is one of the most important indices for public health especially for drinking water consumptions. This study was conducted to survey the presence of heavy metals in drinking water resources of Iran using a systematic review and meta-analysis. The literature search was conducted in data bases of PubMed, Web of Science, EMBASE, Scopus, Google Scholar, and some Persian databases up to 31 July 2018. Of all the articles reviewed (1151 articles), 61 papers were eligible for systematic review. Results indicated variable heterogeneity between studies for different pollutants (I2 between 0 and 100). A subgroup analysis was performed for three different types of water resources such as drinking water, groundwater, and surface water to find the possible source of the heterogeneity. The pooled mean concentration level of iron was the highest at 255.8 (95% CI = 79.48-432.13 µg/l) and vanadium the lowest at 3.21 (95% CI = 1.45-4.98 µg/l). The sequence of metal concentration (µg/l) in descending order is as follows: Fe (255.8) > B (159.81) > Al (158.5) > Zn (130.73) > As (85.85) > Mn (51.61) > Cu (47.98) > Se (42.68) > Pb (37.22) > Co (22.76) > Mo (18.92) > Ni (16.79) > Cr (13.47) > Hg (4.49) > Cd (4.19) > V (3.21). The mean pooled concentration level of Al, As, Se, Pb, and Cd was higher than the WHO guideline and Iran Standard, and the rest of the metals had lower mean pooled concentration level. Pb and Cd were the common heavy metals that existed in all subgroups. As a recommendation, the relationship assessment of water parameters and heavy metals could be addressed in future studies of Iran's water resources.

Desorption kinetics and isotherms of phenanthrene from contaminated soil.

BACKGROUND: Prediction of polycyclic aromatic hydrocarbons (PAHs) desorption from soil to estimate available fraction regarding to initial concentration of the contaminant is of great important in soil pollution management, which has poorly been understood until now. In the present study estimation of fast desorption fraction which is considered as available fraction was conducted by evaluating desorption kinetics of phenanthrene (a three ring PAH) from artificially contaminated soils through the mathematical models. METHODS: Desorption rate of phenanthrene (PHE) was investigated by using the nonionic surfactant Tween80 in a series of batch experiments. The effects of reaction time from 5 to 1440 min and initial PHE concentration in the range of 100-1600 mg/kg were studied. RESULTS: Available fractions of the contaminant were achieved within the first hour of desorption process as the system reached to equilibrium conditions. Experimental data were examined by using kinetic models including pseudo-first-order, pseudo-second-order in four linearized forms, and fractional power. Among the models tested, experimental data were well described by pseudo-second-order model type (III) and (IV) and fractional power equation. Fast desorption rates, as Available fractions were determined 79%, 46%, 40%, 39%, and 35% for initial PHE concentrations of 100, 400, 800, 1200, and 1600 mg/kg respectively. Among the evaluated isotherm models, including Freundlich, Langmuir in four linearized forms, and Temkin, the equilibrium data were well fitted by the first one. CONCLUSION: Applying the nonionic surfactant Tween80 is a useful method to determine available fraction of the contaminant. This method will provide the management of contaminated sites by choosing a proper technique for remediation and predicting achievable treatment efficiency.

Fluoride ion adsorption onto palm stone: Optimization through response surface methodology, isotherm, and adsorbent characteristics data.

In some part of the world, groundwater source can become unsafe for drinking due to the high concentration of fluoride ions [1]. The low cost and facile-produced adsorbent like palm stone could effectively removed fluoride ions through adsorption process. In this dataset, the influence of fluoride ion concentration, solution pH, adsorbent dosage, and contact time on fluoride ion adsorption by palm stones was tested by central composite design (CCD) under response surface methodology (RSM). The data stone carbonized adsorbent was prepared by a simple and facile method at relatively low temperature of 250 °C during 3 h. The adsorbent had the main functional groups of O-H, -OH, Si-H, C=O, N=O, C-C, C-OR, C-H, and C-Br on its surface. At the optimized conditions obtained by RSM, about 84.78% of fluoride ion was removed using the adsorbent. The Langmuir isotherm was suitable for correlation of equilibrium data (maximum adsorption capacity= 3.95 mg/g). Overall, the data offer a facile adsorbent to water and wastewater works which face to high level of fluoride water/ wastewater content.

A new bioindicator, shell of Trachycardium lacunosum, and sediment samples to monitors metals (Al, Zn, Fe, Mn, Ni, V, Co, Cr and Cu) in marine environment: The Persian Gulf as a case.

BACKGROUND: The present work was designed to detect heavy metal contents of Al, Zn, Fe, Mn, Ni, V, Co, Cr and Cu in sediments and shells of the Trachycardium lacunosum collected in polluted and unpolluted areas along the Persian Gulf. METHODS: The samples were taken from surface sediments (0-10 cm) and shells of Trachycardium lacunosum in two separated areas (polluted and unpolluted) in northern part of the Persian Gulf, Asaluyeh Bay, during summer 2013. The prepared samples were analyzed by inductively coupled plasma-optical emission spectrometry (ICP-OES). RESULTS: Based on the results, all measured metals including Al, Zn, Fe, Mn, Ni, V, Co, Cr and Cu were meaningfully higher in the sediment samples of polluted area compared to unpolluted area and the order of metal concentrations in the sediment samples were Cr > Co > V > Ni > Zn > Cu > Fe > Al > Mn in polluted area. In the case of shell samples of Trachycardium lacunosum, polluted area contained significantly higher contents of Al, Zn, Fe, Mn, Ni, Co, Cr and Cu compared to unpolluted area and the order of metal concentrations in the shell samples were Fe > Zn > Al > Mn > Cu > Cr > Ni > Co in the polluted area. CONCLUSION: It was concluded that shells of the Trachycardium lacunosum can be used as a suitable bioindicator for heavy metals in the aquatic environment. Results confirmed that due to the possible contaminations by oil and gas activities near the polluted area perennial monitoring and mitigation measures is extremely necessary.

Evaluation of the knowledge level of health violations in food production, distribution, sales centers and public places and their authorities investigating among the women of Bushehr city.

BACKGROUND: Women and mothers are the most important educational audience to convey health teachings. This study was aimed to evaluate the knowledge level of different types of health violations of food production, distribution, sale centers and public places; and authorities investigating the violations among women referring to health care centers in Bushehr. MATERIALS AND METHODS: In this descriptive-analytical study, which was done cross-sectionally, 600 women who were referred to health care centers affiliated to the Bushehr University of Medical Sciences was selected by convenience sampling. Two-part questionnaire was used to collect data: demographic information and a researcher-designed knowledge survey questionnaire consisted of 25 questions with Cronbach's alpha = 0.7. Data were analyzed with the software SPSS version 13; using Chi-square test and Phi and Cramer test. P ≤ 0.05 was considered to be statistically significant. RESULTS: The findings showed that 56.9% and 26.5% of women had good and moderate knowledge levels regarding health violations, while the general knowledge level of authorities investigating health violations were at the moderate level among 57.3% and at the good level among 15.3% of women. Overall, there was a significant relationship between education level and the women's knowledge level of health violations (P < 0.0001). The relationship between the women's education level and authorities investigating health violations was not significant (P = 0.073). CONCLUSION: Applying interventional methods of education in health violations to the women by health centers can elevate the level of health knowledge among them.

Exploring nursing students' experience of peer learning in clinical practice.

BACKGROUND: Peer learning is an educational process wherein someone of the same age or level of experience level interacts with other students interested in the same topic. There is limited evidence specifically focusing on the practical use of peer learning in Iran. The aim of this study was to explore nursing students' experiences of peer learning in clinical practice. MATERIALS AND METHODS: A qualitative content analysis was conducted. Focus groups were used to find the students' experiences about peerlearning. Twenty-eight baccalaureate nursing students at Bushehr University of Medical Sciences were selected purposively, and were arranged in four groups of seven students each. The focus group interviews were conducted using a semi-structured interview schedule. All interviews were tape-recorded, transcribed verbatim, and analyzed using conventional content analysis method. RESULTS: The analysis identified four themes: Paradoxical dualism, peer exploitation, first learning efficacy, and socialization practice. Gained advantages and perceived disadvantages created paradoxical dualism, and peer exploitation resulted from peer selection and peer training. CONCLUSION: Nursing students reported general satisfaction concerning peer learning due to much more in-depth learning with little stress than conventional learning methods. Peer learning is a useful method for nursing students for practicing educational leadership and learning the clinical skills before they get a job.

Experimental design approach to the optimization of PAHs bioremediation from artificially contaminated soil: application of variables screening development.

BACKGROUND: The effectiveness of bioremediation systems for PAH-contaminated soil may be constrained by physicochemical properties of contaminants and environmental factors. Information on what is the most effective factor in bioremediation process is essential in the decision of what stimulations can be taken to assist the biodegradation efficacy. METHODS: In this study, four factors of surfactant (Tween 80), humic acid (HA), salinity and nutrients in a 2(4) full factorial design were screened in bioremediation of phenanthrene contaminated soil by using a consortium of bacteria. RESULTS: Between the employed levels of the factors only salinity had not significant effect. Optimal concentrations of surfactant, HA and nutrient were obtained by a response surface design. For phenanthrene biodegradation, a central composite face centred design (CCFD) showed that nutrient, surfactant and HA concentrations had highly significant, significant and insignificant effects, respectively. The best conditions with 87.1% phenanthrene biodegradation were 150 mg HA/Kg soil, 12.68 µg/L surfactant, and nutrients as K2HPO4, 0.8; KH2PO4, 0.2 and KNO3, 1 g/L. A high similarity was between the model prediction and experimental results. CONCLUSIONS: This study showed that nutrient with 81.27% efficiency could be considered as the most effective factor for practical implications of bioremediation process for PAHs contaminated soil cleanup strategies.

Comparative investigation of heavy metal, trace, and macro element contents in commercially valuable fish species harvested off from the Persian Gulf.

This study was performed to determine the differences between two commercial species of fish harvested off near the Kharg Island (one of the largest oil terminals in the world) in the Persian Gulf in terms of toxic metals, macro, and trace elements. Samples were analyzed using inductively coupled plasma-optical emission spectrometry (ICP-OES). The results showed that Ca, Li, Mg, P, Se, Sn, Sr, and Zn concentrations were significantly different between the skin and muscle tissues of Scomberomorus guttatus but with the exception of P, there was no significant difference between element levels in the skin and muscle tissues of Otolithes ruber. The S. guttatus contained significantly higher levels of As, Sn, Se, and P in the muscle tissue and Zn in the skin tissue compared to the muscle and skin tissues of Otolithes ruber. The estimated daily intake of the toxic elements including As, Cd, Sb, Pb, and Sn via consumption of these fish were below the established guidelines but due to the potential contamination by oil activities near the island, continuous and permanent monitoring in this region is highly recommended.