Quantitative microbial risk assessment of gastrointestinal illness due to recreational exposure to E. coli and enterococci on the southern coasts of the Caspian Sea.

Background: Gastrointestinal illness refers to a broad range of diseases that affect the digestive system, including infections caused by bacteria, viruses, and parasites. Quantitative Microbial Risk Assessment (QMRA) is a powerful tool used to evaluate the risks associated with microbial pathogens in various environments. The main objective of this study was to conduct a quantitative assessment of gastrointestinal illnesses that occur as a result of exposure to E. coli and enterococci during recreational activities on the southern coasts of the Caspian Sea. Methods: Samples were collected from the recreational beaches along the border line of the Caspian Sea. The samples were analyzed for the presence and enumeration of E. coli and enterococci using the microplate method and membrane filtration techniques. Then, the annual and daily infection risks were computed using the Monte Carlo simulation approach. Results: The results revealed that the risk of daily and annual infections on the coasts of Babolsar was higher than that on the coasts of Sari. Also, in the recreational waters of these beaches, the risk of infection by enterococci was higher than that posed by E. coli. In Babolsar, the average annual infection risk caused by E. coli and enterococci was 0.365 and 1 for children and 0.181 and 0.986 for adults. Also, in Sari, the average annual infection risk caused by E. coli and enterococci was 0.060 and 0.908 for children and 0.027 and 0.815 for adults. In addition, children were more likely than adults to become infected. Conclusion: In light of the study's findings, due to the entry of untreated urban wastewater into the southern part of the Caspian Sea (northern Iran) and the high risk of infectious diseases for children, more control and health measures are necessary for children's swimming.

Bottled water safety evaluation: A comprehensive health risk assessment of oral exposure to heavy metals through deterministic and probabilistic approaches by Monte Carlo simulation.

The consumption of bottled water has witnessed substantial global expansion in recent times. This study aimed to quantitatively evaluate the concentrations of eight heavy metals (As, Ba, Cd, Cr, Mn, Mo, Ni, and Zn) in 71 high-consumption bottled water brands in Iran. Non-carcinogenic and carcinogenic risk assessments were conducted using both deterministic and probabilistic approaches. Point estimation utilizing the Hazard Quotient (HQ) formula and sensitivity analysis employing the Monte Carlo Simulation (MCS) method through 10,000 repetitions in Oracle Crystal Ball® was used to ascertain the health risks associated with heavy metal exposure. Heavy metal concentrations were quantified through Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). HQ point estimation results indicated that Cr exhibited the highest mean HQ value, whereas Cd demonstrated the lowest. In the probabilistic approach, the highest 95 percentile values were observed for Cr and Mo at 3.9E-01, while the lowest values were recorded for Cr and Mn at 1.10E-02. Heavy metal concentrations emerged as critical factors influencing non-carcinogenic and carcinogenic risks across all groups in the sensitivity analysis. The findings highlight the need for ongoing monitoring, research, and targeted regulations to address health risks from heavy metal exposure in bottled water and ensure public well-being.

Assessment of health risk and burden of disease induced by exposure to benzene, toluene, ethylbenzene, and xylene in the outdoor air in Tehran, Iran.

The health risk and burden of disease induced by exposure to benzene, toluene, ethylbenzene, and xylene (BTEX) in the outdoor air in Tehran, 2019 were assessed based on the data of five fixed stations with weekly BTEX measurements. The non-carcinogenic risk, carcinogenic risk, and disease burden from exposure to BTEX compounds were determined by hazard index (HI), incremental lifetime cancer risk (ILCR), and disability-adjusted life year (DALY), respectively. The average annual concentrations of benzene, toluene, ethylbenzene, and xylene in the outdoor air in Tehran were 6.59, 21.62, 4.68, and 20.88 µg/m3, respectively. The lowest seasonal BTEX concentrations were observed in spring and the highest ones occurred in summer. The HI values of BTEX in the outdoor air in Tehran by district ranged from 0.34 to 0.58 (less than one). The average ILCR values of benzene and ethylbenzene were 5.37 × 10-5 and 1.23 × 10-5, respectively (in the range of probable increased cancer risk). The DALYs, death, DALY rate (per 100,000 people) and death rate (per 100,000 people) induced by BTEX exposure in the outdoor air in Tehran were determined to be 180.21, 3.51, 2.07, and 0.04, respectively. The five highest attributable DALY rates in Tehran by district were observed in the districts 10 (2.60), 11 (2.43), 17 (2.41), 20 (2.32), and 9 (2.32), respectively. The corrective measures such as controlling road traffic and improving the quality of vehicles and gasoline in Tehran could reduce the burden of disease from BTEX along with the health effects of other outdoor air pollutants.

Carcinogenic and non-carcinogenic risk assessment of exposure to trace elements in groundwater resources of Sari city, Iran.

The daily intake of trace elements through water resources and their adverse health effects is a critical issue. The purpose of this research was to assess the carcinogenic and non-carcinogenic risks of exposure to iron (Fe), copper (Cu), manganese (Mn), zinc (Zn), chromium (Cr), lead (Pb), and arsenic (As) in groundwater resources of Sari city, Iran. The concentrations of the trace elements in a total number of 66 samples from the groundwater sources were measured using inductively coupled plasma mass spectrometry (ICP-MS). The hazard index (HI) levels of exposure to the trace elements from the groundwater sources for adults, teenagers, and children were 0.65, 0.83, and 1.08, respectively. The carcinogenic risk values of Cr and As in the groundwater sources for children, teenagers, and adults were 0.0001, 0.00009, 0.00007, 0.0003, 0.0002, and 0.0001, respectively, causing a total carcinogenic risk value higher than the acceptable range, and removing Cr and As from the groundwater resources is recommended for safe community water supply.

Assessment of cause-specific mortality and disability-adjusted life years (DALYs) induced by exposure to inorganic arsenic through drinking water and foodstuffs in Iran.

The health risk and burden of disease induced by exposure to inorganic arsenic (iAs) through drinking water and foodstuffs in Iran were assessed. The iAs levels in drinking water and foodstuffs (15 food groups) in the country were determined through systematic review of three international databases (PubMed, Scopus, and Web of Science) and meta-analysis. Based on the results of the systematic review and meta-analysis, the average iAs levels in drinking water and all the food groups at the national level were lower than the maximum permissible levels. The total average non-carcinogenic risk of dietary exposure to iAs in terms of hazard index (HI) was 3.4. The average incremental lifetime cancer risk (ILCR) values of dietary exposure to iAs were determined to be 1.5 × 10-3 for skin cancer, 1.0 × 10-3 for lung cancer, and 4.0 × 10-4 for bladder cancer. Over two-thirds of the non-carcinogenic and carcinogenic risk of dietary exposure to iAs was attributed to bread and cereals, drinking water, and rice. The total annual cancer incidence, deaths, disability-adjusted life years (DALYs), death rate, and DALY rate (per 100,000 people) were assessed to be 3347 (95 % uncertainty interval: 1791 to 5999), 1302 (697 to 2336), 72,606 (38,833 to 130,228), 1.6 (0.87 to 2.9), and 91 (49 to 160). The contribution of mortality in the attributable burden of disease was 95.1 %. The contributions of the causes in the attributable burden of disease were 72 % for lung cancer, 16 % for bladder cancer, and 12 % for skin cancer. Due to the significant attributable burden of disease, national and subnational action plans consisting of multi-disciplinary approaches for risk management of dietary exposure to iAs, especially for the higher arsenic-affected areas and high-risk population groups in the country are recommended.

Integrated ultrasound-assisted magnetic solid-phase extraction for efficient determination and pre-concentration of polycyclic aromatic hydrocarbons from high-consumption soft drinks and non-alcoholic beers in Iran.

In the present research, an ultrasound-assisted magnetic solid-phase extraction coupled with a gas chromatography-mass spectrometry hybrid system was developed for the extraction/determination of trace amounts of polycyclic aromatic hydrocarbons in high-consumption soft drinks and non-alcoholic beers in Iran using magnetite graphene oxide adsorbent. The magnetite graphene oxide was characterized by scanning electron microscope, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and vibrating-sample magnetometer techniques. The highest extraction recovery (73.05%-95.56%) and enrichment factor (90.65-106.38) were obtained at adsorbent mass: 10 mg, adsorption time: 30 min, salt addition: sodium chloride 10% w/v, desorption time: 20 min, eluent type: hexane: acetone (1:1, v/v), and desorption solvent volumes: 200 µl. Under optimum conditions, the linearity range for polycyclic aromatic hydrocarbons determination was 0.2-200 ng/ml with a coefficient of determination > 0.993, the limit of detection = 0.09-0.21 ng/ml, the limit of quantitation = 0.3-0.7 ng/ml, and relative standard deviation < 8.1%, respectively. Relative recoveries in spiked real samples ranged from 94.67 to 109.45% with a standard deviation < 6.05%. The proposed method is effective, sensitive, and reusable and it is promising for the analysis of polycyclic aromatic hydrocarbons residues in environmental samples.

National and subnational burden of disease attributable to occupational exposure to solar ultraviolet radiation (SUVR) in Iran, 2005-2019.

Overexposure to solar ultraviolet radiation (SUVR) can cause skin and eye adverse effects for outdoor workers. In this study, the burden of disease induced by occupational exposure to SUVR and its spatiotemporal trend at national and sub-national levels in Iran, 2005-2019 were assessed. The attributable burden of disease was assessed using the following five datasets: (1) distribution of occupational exposure to SUVR, (2) total incidences and deaths of health outcomes of SUVR exposure, (3) population attributable fractions of the health outcomes of SUVR exposure, (4) age-gender distribution of outdoor workers, and (5) disability-adjusted life year (DALY) calculation constants. During 2005-2019, the attributable DALYs increased from 2442 to 2907 and the attributable DALY rate (per 100,000 workers) slightly decreased from 11.94 to 11.91. The share of YLL in the attributable burden of disease was in the range of 43%-46%. Out of nine causes, about 90% of the attributable burden of disease in 2019 was related to cataracts (29.9%), malignant skin melanoma (27.4%), squamous-cell carcinoma (18.6%), and sunburn (17.2%). During the study period, the attributable DALY rate in women increased by 60.95% (from 5.04 to 8.11) and in men decreased by 2.06% (from 13.03 to 12.76). The total attributable DALYs and DALY rate rose by age during 2005-2019. The contributions of population growth, risk-deleted DALY rates, exposure risk, and population age structure in temporal changes of the attributable burden of disease were 19.27%, 9.13%, -1.35%, and -14.8%, respectively. The three highest attributable DALY rates in 2019 were observed in South Khorasan (21.28), Chahar Mahal and Bakhtiari (17.42), and Kordestan (17.26), respectively. The preventive interventions against SUVR overexposure, regular screenings, and early treatments with an emphasis on occupations with continuous sun exposure and provinces with increasing attributable DALY rates should be considered in the occupational health action plan in the country.

Assessment of burden of disease induced by exposure to heavy metals through drinking water at national and subnational levels in Iran, 2019.

The burden of disease attributable to exposure to heavy metals via drinking water in Iran (2019) was assessed at the national and regional levels. The non-carcinogenic risk, carcinogenic risk, and attributable burden of disease of heavy metals in drinking water were estimated in terms of hazard quotient (HQ), incremental lifetime cancer risk (ILCR), and disability-adjusted life year (DALY), respectively. The average drinking water concentrations of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and nickel (Ni) in Iran were determined to be 2.3, 0.4, 12.1, 2.5, 0.7, and 19.7 µg/L, respectively, which were much lower than the standard values. The total average HQs of heavy metals in drinking water in the entire country, rural, and urban communities were 0.48, 0.65 and 0.45, respectively. At the national level, the average ILCRs of heavy metal in the entire country were in the following order: 1.06 × 10-4 for As, 5.89 × 10-5 for Cd, 2.05 × 10-5 for Cr, and 3.76 × 10-7 for Pb. The cancer cases, deaths, death rate (per 100,000 people), DALYs, and DALY rate (per 100,000 people) attributed to exposure to heavy metals in drinking water at the national level were estimated to be 213 (95% uncertainty interval: 180 to 254), 87 (73-104), 0.11 (0.09-0.13), 4642 (3793-5489), and 5.81 (4.75-6.87), respectively. The contributions of exposure to As, Cd, Cr, and Pb in the attributable burden of disease were 14.7%, 65.7%, 19.3%, and 0.2%, respectively. The regional distribution of the total attributable DALY rate for all heavy metals was as follows: Region 5> Region 4> Region 1> Region 3> Region 2. The investigation and improvement of relatively high exceedance of As levels in drinking water from the standard value, especially in Regions 5 and 3 as well as biomonitoring of heavy metals throughout the country were recommended.

Burden of disease induced by public overexposure to solar ultraviolet radiation (SUVR) at the national and subnational levels in Iran, 2005-2019.

Estimating the burden of diseases induced by overexposure to solar ultraviolet radiation (SUVR) can help to prioritize environmental health interventions. The age-sex specific and cause-specific mortality and disability-adjusted life years (DALYs) attributable to overexposure to SUVR at the national and subnational levels in Iran, 2005-2019 were estimated. The burden of disease induced by overexposure to SUVR was quantified in four steps as follows: (1) estimating exposure to SUVR, (2) estimating total incidences and deaths of target causes, (3) assessing population attributable fractions of the target causes for the SUVR, and (4) calculating the attributable burden of disease. The attributable DALYs, deaths, age-standardized DALY rate, and age-standardized death rate at the national level were determined to be respectively 21896, 252, 42.59, and 0.56 in 2005 and were respectively changed to 28665, 377, 38.76, and 0.53 in 2019. The contributions of causes in the attributable DALYs at the national level were different by year and sex and for both sexes in 2019 were as follows: 46.15% for cataract, 20.36% for malignant skin melanoma, 16.07% for sunburn, 12.41% for squamous-cell carcinoma, and 5.01% for the other five causes. The contributions of population growth, population ageing, risk exposure, and risk-deleted DALY rate in the temporal variations of the attributable burden of disease in the country were +20.73%, +20.68%, +2.01%, and -12.51%. The highest and lowest provincial attributable age-standardized DALY rates in 2019 were observed in Fars (46.8) and Ardebil (32.7), respectively. The burden of disease induced by exposure to SUVR caused relatively low geographical inequality in health status in Iran. Due to increasing trends of the SUVR as well as the attributable burden of disease, the preventive interventions against the SUVR overexposure should be considered in the public health action plan all across the country.

Assessing contribution of bottled water in nutrient absorption using the bottled water nutritional quality index (BWNQI) in Iran.

In this study, the contribution of bottled water in the absorption of nutritional minerals in Iran has been investigated. To calculate the nutritional quality index of bottled water (BWNQI) and evaluate the contribution of bottled water in nutrient absorption; the concentration of nutrient minerals, the standard level of these elements in bottled water, the recommended amount of nutrient mineral and the total consumption of drinking water in different age-sex groups were analyzed. The results showed that the average contribution of bottled water in absorbing the recommended amount of the nutrients of fluoride (F), magnesium (Mg), calcium (Ca), sodium (Na), copper (Cu), zinc (Zn) and manganese (Mn) was 12.16, 4.98, 4.85, 2.12, 0.49, 0.33 and 0.02%, respectively. According to the BWNQI index, the bottled water quality was as follows: 53.5% poor, 36.6% marginal, 7% fair, 2.81% good. Although most of the bottled water studied in this research were mineral water, a significant portion of them had poor nutritional quality, so the addition of minerals needed by the body through bottled water should be given more attention by the bottled water manufacturers and suppliers.

Spatiotemporal analysis of solar ultraviolet radiation based on Ozone Monitoring Instrument dataset in Iran, 2005-2019.

The solar ultraviolet radiation (UVR) at national, provincial and county levels in Iran during 2005-2019 were determined based on Ozone Monitoring Instrument (OMI) dataset. The temporal (annual and monthly) trends and spatial distributions of the UVR in terms of erythemally weighted daily dose (EDD), erythemally weighted irradiance at local solar noon time (EDR), and UV index and the major factors influencing the spatiotemporal trends were analyzed. The population-weighted average values of EDD, EDR, and UV index in Iran were respectively 3631 J/m2, 176.3 mW/m2, 7.1 in 2005 and rose by 0.22% per year to 3744 J/m2, 181.7 mW/m2, and 7.3, respectively in 2019, but the annual trend was not statistically significant. The EDD in Iran during the study period exhibited the highest monthly average value in June (6339 J/m2) and the lowest one in December (1263 J/m2). The solar UVA/UVB ratios at the national level during 2005-2019 were considerably lower in summer. The EDD provincial average values in the study period were in the range of 2717 (Gilan) to 4424 J/m2 (Fars). The spatiotemporal variations of the solar UVR parameters were well described by the linear models as a function of cloud optical thickness (COT), ozone column amount, surface albedo, latitude, and altitude (R2 > 0.961, p value < 0.001) and the temporal changes of the solar UVR parameters were mainly caused by the COT. The results indicated that non-burning exposure to solar UVR in summer can be more efficient for vitamin D synthesis due to higher contribution of UVB in the solar UVR. The spatial distributions and temporal trends should be considered to determine the optimal duration, time and condition of exposure to the solar UVR for the public and occupational training and public health measures.

An innovative index for assessing vulnerability of employees of different occupations from the COVID-19 pandemic in Iran.

The vulnerability of employees of different occupations from the Coronavirus disease 2019 (COVID-19) pandemic in Iran was assessed using an innovative index. The vulnerability index was developed in five steps as follows: (1) determining the principles and components of employees' susceptibility and resilience, (2) weighting the principles and components, (3) converting the levels of components to the sub-index values, (4) introducing the aggregation functions, and (5) characterizing the vulnerability index values in five categories as very high (80-100), high (65-79), medium (50-64), low (30-49), and very low (0-29). The average values of susceptibility, resilience, and vulnerability index of the employees were determined to be 35.2 ± 15.0, 73.9 ± 17.0, and 32.9 ± 12.7, respectively. The average resilience of the employees was more desirable than their average susceptibility. The distribution of the employees into the vulnerability index categories was 46.3% for very low, 41.9% for low, 3.6% for medium, and 8.2% for high. The worst cases of susceptibility and resilience principles were exposure to contaminated surfaces (59.1 ± 22.8) and top management commitment (66.6 ± 23.1). The elderly staff (especially over 50 years old), employees with low education levels, and employees in private and self-employment sectors were significantly more vulnerable (p value < 0.01) from the COVID-19 pandemic. The principles with significant incremental effects on the vulnerability index (p value < 0.05) were respectively top management commitment (+1.78), exposure to COVID-19 patients at work (+1.36), exposure to contaminated surfaces (+0.82), installing clear shields and wearing PPE (+0.59), observance of social distancing (+0.48), and just culture (+0.22). An especial plan to support the more vulnerable employees with an emphasis on the principles with the most incremental effects on the vulnerability index can efficiently control the inequality between the employees as well as occupational transmission of the COVID-19 in Iran.

Remediation of oily sludge wastes using biosurfactant produced by bacterial isolate Pseudomonas balearica strain Z8.

Biological treatment of oily sludge wastes was studied using an isolated halo-tolerant strain Pseudomonas balearica strain Z8. An oily sludge sample was obtained from oil fields of south waste of Iran and was fully characterized. The initial TPH content was 44,500 mg kg-1. The ability of Pseudomonas balearica strain Z8 in production of biosurfactant was investigated using oil displacement method. Results demonstrated that isolated strain is a biosurfactant producing bacteria. The CMC and emulsification index [E24] of produced biosurfactant were 90 mg L-1 and 44% for crude oil. Effect of operational parameters including nitrogen source, sludge/water ratio and temperature were investigated against the time. The most TPH removal of 35% was observed for nitrogen source of NH4Cl, sludge/ water ratio of 1:7 and temperature of 40 °C.

Age-sex specific and cause-specific health risk and burden of disease induced by exposure to trihalomethanes (THMs) and haloacetic acids (HAAs) from drinking water: An assessment in four urban communities of Bushehr Province, Iran, 2017.

Health risk and burden of disease induced by exposure to trihalomethanes (THMs, four compounds) and haloacetic acids (HAAs, 5 compounds) from drinking water through ingestion, dermal absorption, and inhalation routes were assessed based on one-year water quality monitoring in four urban communities (Bandar Deylam, Borazjan, Bushehr, and Choghadak) of Bushehr Province, Iran. The total average concentrations of THMs and HAAs at all the communities level were determined to be 92.9 ± 43.7 and 70.6 ± 26.5 µg/L, respectively. The dominant components of the THMs and HAAs were determined to be tribromomethane (TBM, 41.6%) and monobromoacetic acid (MBAA, 60.8%), respectively. The average contributions of ingestion, dermal absorption, and inhalation routes in exposure to the chlorination by-products (CBPs) were respectively 65.0, 15.4, and 19.6%. The total average non-carcinogenic risk as the hazard index (HI) and incremental lifetime cancer risk (ILCR) of the CBPs at all the communities level were found to be 4.03 × 10-1 and 3.16 × 10-4, respectively. The total attributable deaths, death rate (per 100,000 people), age-weighted disability-adjusted life years (DALYs), and age-weighted DALY rate for all ages both sexes combined at all the communities level were estimated to be 1.0 (uncertainty interval: UI 95% 0.3 to 2.8), 0.27 (0.08-0.75), 30.8 (11.3-100.1), and 8.1 (3.0-26.4), respectively. The average contribution of mortality (years of life lost due to premature mortality: YLLs) in the attributable burden of disease was 94.7% (94.4-95.6). Although in most of cases the average levels of the CBPs were in the permissible range of Iranian standards for drinking water quality, the average values of ILCRs as well as attributable burden of disease were not acceptable (the ILCRs were higher than the boundary limit of 10-5); therefore, implementation of interventions for reducing exposure to CBPs through drinking water especially in Kowsar Dam Water Treatment Plant is strictly recommended.

Enhancing photo-degradation of ciprofloxacin using simultaneous usage of eaq- and OH over UV/ZnO/I- process: Efficiency, kinetics, pathways, and mechanisms.

The aim of this study is to develop the process relies on the UV irradiation of ZnO and I-, i.e. UV/ZnO /I- (UZI), to create both oxidizer and reducer agents simultaneously for photo-degradation of the Ciprofloxacin (CIP). This paper shows that while applying UV irradiation, UV/ZnO and UV/I- for 20 min can lead to achieve 37.5%, 58.12%, and 61.4% photo-degradation of 100 mg L-1 CIP at pH 7, respectively. Moreover, the UZI treatment can provide 91.54% photo-degradation efficiency. The LC-MS analysis of the UZI effluent indicates that 10 min process was adequate to degrade CIP into simple ring-shaped metabolites while 15 min treatment, mostly of CIP intermediates were linear and biodegradable organic compounds. Furthermore, fourteen little fragments were identified in the CIP photo-degradation via UZI, during the photoreaction time of 2.5 to 20 min. Then, a pseudo first-order kinetics equation was utilized to model the observed photo-degradation process. Finally, the computational results show that the increased concentration of the CIP solution from 100 to 400 mg L-1 decreases the observed rate constant (kobs) from 0.4125 to 0.2189 min-1 while increases the photoreaction rate (robs) from 41.25 to 87.56 mg L-1 min-1.

Age-sex specific disability-adjusted life years (DALYs) attributable to elevated levels of fluoride in drinking water: A national and subnational study in Iran, 2017.

National and subnational burden of disease attributable to elevated fluoride levels in drinking water apportioned by sex, age group, province, and community type in Iran, 2017 were quantified based on disability-adjusted life years (DALYs). The attributable burden of disease was estimated using four input data: (1) effect size of elevated drinking water fluoride levels for dental and skeletal fluorosis, (2) population distribution of drinking water fluoride levels, (3) the threshold levels of fluoride in drinking water for contribution in dental and skeletal fluorosis, and (4) age-sex distribution of population. The attributable burden of disease was only related to dental fluorosis, because the fluoride levels were lower than the threshold value for skeletal fluorosis (4.0 mg/L) in all of the cases. The national attributable prevalence (per 100,000 people), DALYs, and DALY rate in 2017 were calculated to be 60 (95% uncertainty interval 48-69), 3443 (1034-6940), and 4.31 (1.29-8.68), respectively. The national attributable burden of disease was not significantly different by sex, but was affected by age and community type in a manner that the highest DALY rate was related to the age group 10-14 y (6.06 [1.82-12.21]) and over 66% of the national attributable DALYs occurred in rural communities. The attributable burden of disease occurred only in 10 out of 31 provinces and about 94% of the attributable DALYs were concentrated in four provinces Fars (1967 [592-3964]), Bushehr (414 [124-836]), West Azarbaijan (400 [120-808]), and Hormozgan (377 [113-761]). Implementation of fluoride-safe drinking water supply schemes in the four leading provinces can prevent most of the national health losses and partly compensate the increasing trend of disease burden from oral conditions at the national level.

Health risk of phthalates in water environment: Occurrence in water resources, bottled water, and tap water, and burden of disease from exposure through drinking water in tehran, Iran.

Occurrence of phthalates in water resources, bottled water, and tap water, and health risk of exposure to the phthalates through drinking water in Tehran, Iran, 2018 were studied. The six phthalates with the most health and environmental concerns, including di-(2-ethylhexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), di-n-butyl phthalate (DBP), diethyl phthalate (DEP), dimethyl phthalate (DMP), and di-n-octyl phthalate (DNOP) were monitored in drinking water and water resources. The average levels (±standard deviation: SD) of the total phthalates in drinking water from the water distribution system, bottled water, surface waters, and ground waters were determined to be 0.76 ±â€¯0.19, 0.96 ±â€¯0.10, 1.06 ±â€¯0.23, and 0.77 ±â€¯0.06 µg/L, respectively. The dominant compounds in the phthalates were DMP and DEHP causing a contribution to the total phthalate levels higher than 60% in all the water sources. The phthalate levels of drinking water significantly increased by contact of hot water with disposable plastic and paper cups and by sunlight exposure of bottled water (p value < 0.05). The hazard quotients (HQs) of DEHP, BBP, DBP, and DEP for all ages both sexes combined were determined to be 1.56 × 10-4, 1.01 × 10-5, 1.80 × 10-5, and 1.29 × 10-6, respectively that were much lower than the boundary value of 1.0. The disability-adjusted life years (DALYs) and DALY rate (per 100,000 people) attributable to DEHP intake through drinking water for all ages both sexes combined were estimated to be 6.385 (uncertainty interval: UI 95% 1.892 to 22.133), and 0.073 (0.022-0.255), respectively. The proportion of mortality in the attributable DALYs was over 96%. The attributable DALY rate exhibited no significant difference by sex, but was considerably affected by age in a manner that the DALY rates ranged from 0.052 (0.015-0.175) in the age group 65 y plus to 0.099 (0.026-0.304) in the age group 5 to 9 y. Both the carcinogenic and non-carcinogenic health risks of the phthalates in drinking water were considered to be very low. The results can also be of importance in terms of developing frameworks to expand the domain of burden of disease study to the other environmental risks.

Synthesis and characterization of a new magnetic adsorbent for removal of 4-nitrophenol: application of response surface methodology.

Magnetic modified graphene oxide was synthesized as a new modified magnetic nano-composite (MMNC) by a simple sonochemical-hydrothermal method. The sonochemical reaction was employed to exfoliate, functionalize and decorate neomycin on graphene oxide sheets. Nickel ferromagnetic particles were synthesized by hydrothermal co-precipitation method and decorated on neomycin-modified graphene oxide. The morphology and chemical structure of MMNC were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction spectroscopy. The adsorption capability of MMNC for removal of phenolic compounds was assessed through adsorption of 4-nitrophenol (4-NP) from aqueous solution. The three-factor Box-Behnken design coupled with response surface method was applied to evaluate and optimize the important variables which affect the adsorption process. A significant quadratic model (p-value <0.05, R2 (adj) = 0.9593) was derived using analysis of variance. The maximum adsorption capacity of 125.4 mg 4-NP/g MMNC at pH 6 was obtained, which was comparable in some cases and higher than most adsorbents reported in the literature. The presence of neomycin on graphene oxide sheets improved the maximum adsorption capacity of the nano-sorbent up to 28% (from 98.7 to 125.4 mg 4-NP/g adsorbent). The adsorption isotherms fitted well with the Langmuir model (Langmuir constant b = 0.064 l/mg, R2 = 0.9989) and the kinetic study showed that the nitrophenol uptake process followed the pseudo-second-order rate expression (R2 ≥ 0.9960, pseudo-second-order constant K2 ≥ 1.7 × 10-3).

Age-sex specific and sequela-specific disability-adjusted life years (DALYs) due to dental caries preventable through water fluoridation: An assessment at the national and subnational levels in Iran, 2016.

We assessed disability-adjusted life years (DALYs) due to dental caries preventable through water fluoridation apportioned by sex, age group, sequela, province, and community type in Iran, 2016. The burden of disease due to dental caries was extracted from the Global Burden of Disease Study 2016 (GBD 2016) and the caries preventive effect of water fluoridation was calculated using a database of fluoride levels in drinking water. All the preventable DALYs were caused by years lived with disability (YLDs) because of the non-fatal character of dental caries. DALYs and DALY rate (per 100,000 people) preventable through water fluoridation at the national level in 2016 were 14,971 (95% uncertainty interval 7348- 24,725) and 18.73 (9.19-30.93), respectively. The national population preventable fraction (PPF) of dental caries by water fluoridation was determined to be as high as 0.176 (0.141-0.189). The share of sequelae in the preventable DALYs at the national level were estimated to be 76.8% for edentulism and severe tooth loss, 21.4% for caries of permanent teeth, and 1.8% for caries of deciduous teeth. The national DALYs and DALY rate preventable through water fluoridation exhibited no difference by sex, but considerably increased by age from 110 (37-223) and 1.5 (0.5-3.1) for the age group 0-4 y to 4331 (2334-6579) and 88.9 (47.9-135.1) for the age group 65 y and older, respectively. Over 80% of the national preventable DALYs occurred in urban areas due to higher population and lower coverage of fluoridated drinking water. The highest provincial DALYs and DALY rate preventable by water fluoridation were observed in Tehran and Gilan to be 3776 (1866-6206) and 37.2 (18.6-60.8), respectively. The results indicated that water fluoridation can play a profound role in the promotion of dental public health and compensate the spatial inequality and increasing temporal trend of health losses from dental caries at the national level.

The Concentration of BTEX in the Air of Tehran: A Systematic Review-Meta Analysis and Risk Assessment.

In the current study, the concentration of some pollutants which are categorized as volatile organic compounds (VOCs), including benzene (B), toluene (T), ethylbenzene (E), and o-xylenes (o-X), in the air of Tehran was evaluated by the aid of a systematic review and meta-analysis approach. Also, the health risk for the exposed population was estimated using the recommended methods by the Environmental Protection Agency (EPA). The rank order based on their concentration in BTEX was benzene (149.18 µg/m³: 31%) > o-xylene (127.16 µg/m³: 27%) > ethylbenzene (110.15 µg/m³: 23%) > toluene (87.97 µg/m³: 19%). The ratio B/T in this study was calculated as 1.69, repressing that both stationary and mobile sources of emission can be considered as the main sources for benzene and toluene. Moreover, strong photochemical activity in Tehran was demonstrated by the high ratio of E/o-X. Meta-regression indicates that the concentration of BTEX has insignificantly (p-value > 0.05) increased over time. The BTEX compounds based on the target hazard quotient (THQ) were ordered as benzene > o-xylene > ethylbenzene > toluene. Percentile 95% of THQ due to benzene (4.973) and o-xylene (1.272) was higher than a value of 1. Percentile 95% excessive cancer risk (ECR) for benzene (1.25 × 106) and ethylbenzene (1.11 × 106) was higher than a value of 1.00 × 106. The health risk assessment indicated that the population of Tehran are at considerable non-carcinogenic and carcinogenic risks.