Evaluating Heavy Metals in Human Breast Milk: a Cross-Sectional Study from Mining and Agricultural Areas in Northwestern Iran.

This study aimed to assess the levels of heavy metals in the breast milk of women residing in the mining and agricultural areas of East Azerbaijan province in Iran. This cross-sectional study analyzed 68 lactating mothers from mining (n = 28) and agricultural (n = 40) areas of East Azerbaijan province in Iran between June 2022 and March 2023. The study used an Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) to measure the concentrations of heavy metals, including arsenic (As), chromium (Cr), copper (Cu), and iron (Fe). A semi-quantitative food frequency questionnaire (SQ-FFQ) was used to collect data on the dietary and sociodemographic characteristics of the mothers. Although the concentration of arsenic (As) was below the limit of detection (LOD), the mean concentrations of chromium (Cr), copper (Cu), and iron (Fe) were 1.11, 0.87, and 13.25 mg/L in agricultural areas and 0.83, 0.93, and 11.35 mg/L in mining areas, respectively. The concentrations of Cr (p < 0.001) and Fe (p = 0.019) were significantly higher in the breast milk of women residing in agricultural areas. However, the concentration of Cu was significantly higher (p = 0.085) in the breast milk of women living in mining areas. Additionally, lactation age had a significant effect on Cu levels (p = 0.015), with a negative coefficient of -0.011. The study indicates that the levels of heavy metals in breast milk can be influenced by the exposure to pesticides, fertilizers, volcanic soil, and disparities in access to post-natal care and iron supplements.

Advances in microbial exoenzymes bioengineering for improvement of bioplastics degradation.

Plastic pollution has become a major global concern, posing numerous challenges for the environment and wildlife. Most conventional ways of plastics degradation are inefficient and cause great damage to ecosystems. The development of biodegradable plastics offers a promising solution for waste management. These plastics are designed to break down under various conditions, opening up new possibilities to mitigate the negative impact of traditional plastics. Microbes, including bacteria and fungi, play a crucial role in the degradation of bioplastics by producing and secreting extracellular enzymes, such as cutinase, lipases, and proteases. However, these microbial enzymes are sensitive to extreme environmental conditions, such as temperature and acidity, affecting their functions and stability. To address these challenges, scientists have employed protein engineering and immobilization techniques to enhance enzyme stability and predict protein structures. Strategies such as improving enzyme and substrate interaction, increasing enzyme thermostability, reinforcing the bonding between the active site of the enzyme and substrate, and refining enzyme activity are being utilized to boost enzyme immobilization and functionality. Recently, bioengineering through gene cloning and expression in potential microorganisms, has revolutionized the biodegradation of bioplastics. This review aimed to discuss the most recent protein engineering strategies for modifying bioplastic-degrading enzymes in terms of stability and functionality, including enzyme thermostability enhancement, reinforcing the substrate binding to the enzyme active site, refining with other enzymes, and improvement of enzyme surface and substrate action. Additionally, discovered bioplastic-degrading exoenzymes by metagenomics techniques were emphasized.

Spatial trend and probabilistic health risk assessment of heavy metals, nitrate, and fluoride in groundwater resources, West Azerbaijan province, Iran.

The quality of water resources used for drinking and their health effects is vitally important. The present study investigated the concentrations of F-, NO3-, and metal elements like Hg, Mn, As, and Pb in the groundwater resources and their health risk assessment on the west margin of Urmia Lake, Iran. Sampling points were selected and taken from 121 groundwater resources in the summer of 2014. Heavy metals (Pb, As, Mn, and Hg) were measured by ICP-OES (inductively coupled plasma optical emission spectrometer, model: Arcos, Germany), and some ions (Na+, NO3-, F-, and Cl-) by flame photometer and spectrophotometer according to the standard methods, respectively. The nitrate concentration range in groundwater samples measured from 1.7 to 137 mg/L and fluoride from 0.4 to 4.5 mg/L. The probabilistic method and Monte Carlo simulation were used to estimate carcinogenic and noncarcinogenic risks. The concentration of study elements in most samples was obtained in the WHO (World Health Organization) recommended range. The order of HM (heavy metal) concentration is based on the overall mean: Mn > As > Hg > Pb. The HI (hazard index ) level was found to be more than 1 for noncarcinogenic risk for As and NO3- and permissible risks for the other elements and fluoride. ELCR (excess lifetime cancer risk) levels of As were acceptable, except for some sampling points, the central region in the study area, near the seashore of Urmia Lake. Finally, it can be stated that the groundwater resources in the studied area are acceptable for drinking in most places. Still, due to the effects of As and NO3- contaminated water, the quality is unacceptable for drinking in some places. So, monitoring water quality is recommended by finding contamination sources to decrease the health risks of drinking consumption.

Optimizing ozone dose and contact time for removal of antibiotic-resistant P. aeruginosa, A. baumannii, E. coli, and associated resistant genes in effluent of an activated sludge process in a municipal WWTP.

This study aimed to investigate the impact of ozonation on inactivation of antibiotic-resistant bacteria (ARB) including E. coli, P. aeruginosa, and A. baumannii, as well as on removal of 16S-rRNA gene and their associated antibiotic-resistant genes (ARGs) indigenously present in effluent of municipal wastewater treatment plant. The Chick-Watson model was used to describe bacterial inactivation rates at specific ozone doses. Maximum reduction of total cultivable A. baumannii, E. coli, and P. aeruginosa were found to be 7.6, 7.1, and 4.7 log, respectively, with the highest ozone dose of 0.48 gO3/gCOD at 12 min contact time. According to the study results, complete inactivation of ARB and bacterial regrowth was not observed after 72 h incubation. The culture methods overestimated the performance of disinfection processes and propidium monoazide combined with qPCR, and showed the presence of viable but non-culturable bacteria after ozonation. ARGs were more persistent to ozone than ARB. The results of this study highlighted the significance of specific ozone dose and contact time in ozonation process considering the bacterial species and associated ARGs as well as the wastewater physicochemical characteristics, in order to help diminish the entrance of the biological microcontaminants into the environment.

Health and ecological risks assessment of heavy metals and metalloids in surface sediments of Urmia Salt Lake, Northwest of Iran.

Urmia Lake, in the northwest of Iran, is the largest body of saline water in the Middle East, which has been desiccated in recent decades. To investigate the pollution status and ecological-health risks of heavy metals and metalloids in the surface sediments of this lake, 26 sediment samples were collected along the salt marshes of the lake and were analyzed for heavy metals and metalloid concentrations. The potential ecological risk assessment was carried out using enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), and potential ecological risk (Eri) standard indices. The average concentrations (mg kg-1) of heavy metals and metalloids were as follows: Fe (11,714) > Sr (320.8) > Mn (274.3) > V (28.5) > Cu (24.7) > Zn (21.2) > As (17.3) > Ni (14.8) > Cr (12.6) > Pb (11) > Co (4.0) > U (1.7), Hg (0.6) > Mo (0.36). The concentrations of As, Hg, and Sr in lake sediments were higher than geochemical background values. The non-carcinogenic risks caused by heavy metals and metalloids were insignificant regarding health risks. Levels of carcinogenic risk for metal(loid)s were in the acceptable ranges (10-6-10-4). The ecological risk was low, except for As, Sr, and Hg which showed moderate to significant EF, Igeo, and CF values. Arsenic and Sr were enriched in the surface sediments in desiccated parts of the lake due to complete lake water evaporation. It seems that further drying of the lake increases the potential ecological risk of heavy metals and metalloids in the surface sediments of Urmia Lake.

Investigation of SARS-CoV-2 RNA contamination in water supply resources of Tabriz metropolitan during a peak of COVID-19 pandemic.

It is crucial to have access to clean water resources during the COVID-19 pandemic for hygiene, since virus infection through wastewater leaks in metropolitan areas can be a threat. Accurate monitoring of urban water resources during the pandemic seems to be the only way to confirm safe and infected resources. Here, in this study, the amount of Severe Acute Respiratory Syndrome Coronavirus 2's Ribonucleic Acid (SARS-CoV-2 RNA) in the Tabriz urban water network located in the northwest of Iran was investigated by an extensive sampling of the city's water sources at a severe peak of the COVID-19 pandemic. The sampling process comprised a range of water sources, including wells, qanats, water treatment facilities, dams, and reservoirs. For each sample, a combination of polyethylene glycol (PEG) and sodium chloride (NaCl) was used for concentration and a laboratory RNA-based method was conducted for quantification. Before applying the extraction and quantification procedure to real samples, the proposed concentration method was verified with synthetic serum samples for the first time. After the concentration, RNA extraction was done by the BehPrep extraction column method, and Reverse Transcription Polymerase Chain Reaction (RT-PCR) detection of the virus was done by Covitech COVID-19 RT-PCR kit. In none of the water supply resources, SARS-COV-2 RNA has been detected except in a sample grabbed from a well adjacent to an urban wastewater discharge point downstream. The results of molecular analysis for the positive sample showed that the CT value and concentration of the virus genome were equal to 32.57 and 5720 copies/L, respectively. Quantitative analysis of real samples shows that the city's water network was safe at the time of the study. However, given that the positive sample was exposed to wastewater leakage, periodic sampling from wells and qanats is suggested during the pandemic until it can be proven that the leakage to these water sources is impossible.

Characterization of antibiotic resistance genes and bacteria in a municipal water resource recovery facility.

Municipal water resource recovery facilities (WRRFs) are important sources of antibiotic-resistant bacteria and genes (ARB and ARGs). In this study, antibiotic-resistant total heterotrophic bacteria (THBR ) counts (CFU/ml) cultivated from influent, effluent of activated sludge process, and outflow of disinfection unit of an urban WRRF were investigated for the presence of 16, 32, 64, and 128 µg/ml of nine antibiotics. The isolates of Pseudomonas spp., Acinetobacter spp., and Escherichia coli obtained from effluent of activated sludge process were subjected for molecular identification by detecting the 16S rRNA gene sequences. Additionally, using the polymerase chain reaction method (PCR), the isolates were investigated for the presence of blaSHV , blaTEM , blaCTX-M , blaVIM , sul1, and qnrS genes. According to the results, the abundance of THBR counts was not significantly reduced by the biological treatment except for cefixime and sulfamethoxazole; it also increased for some antibiotics after disinfection unit. The average removal efficiency of THBR resistant to ciprofloxacin, sulfamethoxazole, and ceftazidime were 7.9 ± 1.7%, 41.8 ± 2.1%, and 14.4 ± 6.2%, respectively. Also, all the tested isolates were resistant to at least four antibiotics. For all antibiotics, the resistance ratio (THBR /THB) significantly increased in the effluent and after chlorination unit. Among 12 resistant isolates, blaTEM and sul1 genes were the most frequently detected ones involved in 92% and 83% of the isolates, respectively. Both blaTEM and sul1 genes were found in 100% of E. coli, and 83% and 67% of Pseudomonas spp. isolates, respectively. Further efforts are necessary to limit the transmission of ARB and ARGs from WRRFs into the environment and prevent human health threats. PRACTITIONER POINTS: The ratio of resistance significantly increased after biological treatment. Up to 40% of heterotrophic bacteria in the effluent was antibiotic resistant. blaTEM and sul1 genes were more prevalent (92%) in all isolates of bacteria. Both blaTEM and sul1 genes were found in 100% of E. coli isolates. Pseudomonas spp. holds blaTEM and sul1 genes in 83% and 67% of isolates, respectively.

Environmental impact assessment of salt harvesting from the salt lakes.

Urmia Saline Lake, USL which is registered as an international park by the United Nations, has suffered hypersalinity and serious dryness in recent years. Increasing the dryness trend has been led to a great tendency, especially by private sectors to harvest salt from different parts of the bed sediments. During this study the four- step process was used for environmental impact assessment of such a large scale salt harvesting activities with specialized Folchi matrix and enriched by data on heavy metal concentrations in the limited number of sediment samples. Impact analysis using matrix showed that the most significant impacts were on environmental components, namely "land use", "gradient and topography of the lake bed" and "hydrology and lake water quality" with score values of 73.22, 73.21 and 72.45, respectively. The mean concentrations of As, Cd, Cr, Hg, Pb, Ni and Zn in salt and sediment samples were 15.2±8.8, 0.05±0.047, 15±8.2, 0.54±0.3, 11.9±6.28, 15.4±9.56 and 22.3±13.66 mg/kg, respectively. The higher concentration of arsenic and lead in comparison with earth crust averages, warns that dispersion of salt particles from storage piles may affect local people's health. This study provides readers and authorities with environmental impacts of salt harvesting from unique saline Lake of Iran, presents effective management options such as stopping any unlicensed and unrestrained salt harvesting activities on the USL bed, avoiding deep excavations, minimizing accumulation of piles to prevent the diffusion of salt particles etc. and also specialized the Folchi matrix for application in similar projects.

Temporospatial variation and health risk assessment of trihalomethanes (THMs) in drinking water (northwest Iran).

Trihalomethanes (THMs) are one of the most common classes of disinfection by-products. In this study, the temporospatial trends and health risks due to exposure to THMs in the Tabriz water distribution network were investigated. THM series were analyzed using gas chromatography equipped with electron capture detector. The non-carcinogenic and carcinogenic risks due to exposure to THMs were calculated using Monte Carlo simulations. Mean concentrations of THMs in winter and spring were 10.2 ± 9.3 µg/l and 252 ± 185.9 µg/l, respectively. More than 80% of THMs identified were bromodichloromethane. The mean values of lifetime cancer risk (LTCR) of THMs were calculated as 4.23E-06 and 2.38E-04 for winter and spring, respectively. This study showed that there were noticeable levels of THMs in Tabriz water distribution network, especially in the center of the city. Although the non-cancer risk through THMs was below permissible recommended levels, the cancer risk likely remains due to high levels of THMs in some locations.

Spatial variation and quantitative screening level assessment of human risk from boron exposure in groundwater resources of western edge of the Lake Urmia, Iran.

Boron is a ubiquitous element and exposure to high concentrations of boron in drinking water may lead to health outcomes. This study aimed to analyze boron in rural drinking water resources located at the west of Urmia Lake. An innovative risk matrix was developed for faster assessment of risk status and adaptation of mitigation approaches. The mean boron concentration in 121 drinking water sources from 301 villages obtained 1477 ± 1683 µg/L. In the west of Urmia lake and northwestern parts of the lake (east of Salmas city), boron concentrations were up to twice the World Health Organization (WHO) guidelines. Using regional screening levels calculator of the U.S. Environmental Protection Agency (US.EPA), as a deterministic risk assessment model, the total risks/Non-carcinogenic hazard index (HI) risks from exposure to 13,000 and 2600 µg/L of boron obtained 1.94E+00 and 3.91E-01, respectively. More investigations are recommended for better understanding of the extent of contamination in the study area.

First indoor radon mapping and assessment excess lifetime cancer risk in Iran.

Radon (222Rn) is believed to be the main contributor to lung cancer second to smoking. The first national indoor radon map derived from some scattered regional radon surveys in Iran. The arithmetic mean of indoor radon concentration was calculated to 117.4 ±â€¯97.7 Bq/m3. The mean excess life time cancer risk (ELCR) values were found to be in the range of 0.1%-4.26%, with an overall average value of 1.01%. The mean radon-induced lung cancer risk was 46.8 per million persons. Absence of sufficient indoor radon data showed that national wide monitoring programs should be activated in uncovered areas. Meanwhile, in order to provide further baseline values for radon mapping, we attempted to survey the radon levels inside 50 dwellings of Shabestar County in northwest of Iran. The investigation was also focused on the effects of some buildings related variables. The radon levels recorded varied from 3.92 to 520.12 Bq/m3, with a mean value of 56.19 ±â€¯45.96 Bq/m3. In 9% of dwellings radon concentration exceeded 100 Bq/m3, the limit recommended by the World Health Organization. The average annual effective dose received by the residents of studied area was calculated to be 1.4 mSv. The ELCR was estimated to be 0.54%.

Micronutrient and heavy metal concentrations in basil plant cultivated on irradiated and non-irradiated sewage sludge- treated soil and evaluation of human health risk.

Gamma irradiation is regarded as a promising alternative method for sewage sludge (SS) treatment. To evaluate the human health risk and effects of gamma irradiated and non-irradiated SS (SSGI and SSNI, respectively) on micronutrient and heavy metal concentrations in basil (Ocimum basilicum L.) as a test plant, a greenhouse experiment based on completely randomized design was conducted with control (without SS and irradiation) and 15, 30 and 60 g kg-1 of SSNI as well as SSGI (irradiated with doses of 5, 10 and 20 kGy) with three replicates. The results indicated that the concentrations of copper, zinc, iron, nickel, lead, and cadmium in SSGI and SSNI treatments were greater than the limits set by FAO/WHO for vegetables or by European Commission for food. The target hazard quotient (THQ) of all metals except lead in the treatments with >15 g kg-1 SSGI or SSNI and the hazard index (HI) in the control treatment were lower than the threshold value of 1, but the HIs in SSNI and SSGI treatments were greater than the threshold value. Nevertheless, no significant differences existed between most THQs and HIs from dietary intake of basil grown in SSGI as compared with SSNI. It was concluded that the basil cultivated under tested levels of SSGI and SSNI is not permissible for human consumption.

Investigation of aerosols pollution across the eastern basin of Urmia lake using satellite remote sensing data and HYSPLIT model.

BACKGROUND: Desiccation of the world's second hypersaline lake, Lake Urmia, has drawn attention toward the feasibility of particle emissions from the lakebed to downwind regions. Therefore, this research was conducted to study spatiotemporal variations of aerosols across the eastern basin of the lake during 2001 to 2016. METHODS: The Aerosol Optical Depth (AOD) products of Moderate-resolution Imaging Spectroradiometer (MODIS), extracted from Terra platform for 999 rural and urban areas and compared over adjacent (Shabestar, Osku, Azarshahr, Ajabshir, Bonab, Malekan), middle (Tabriz and Maragheh) and far (Bostanabad, Heris, and Sarab) counties. Number of dusty days and direction of high wind speeds (≥ 11 m/s) were acquired from the East Azerbaijan Meteorological Organization and analyzed. Moreover, performing the backward trajectory model, the origin and distribution of aerosols were determined at altitudes of 500, 1000 and 2000 m. RESULTS: The spatiotemporal variations of AOD provided statistically significant correlations (R2 ≥ 0.5 and p < 0.05) against the number of dusty days. AOD value was higher between 2009 and 2016 and estimated to be 0.36, 0.33 and 0.31 over adjacent, middle and far areas, respectively. Analysis of wind direction and trajectory plots implied that the particulate matter (PM) of study area was mainly transported from Iraq and Syria, especially in April, May and June months. CONCLUSIONS: PM has followed an increasing trend, while the adjacent areas have experienced higher pollution compared to far counties. The southwestern winds can play an important role in transportation of aerosols from either lakebed or western countries to the study area.

Carcinogenic and non-carcinogenic risk assessments of arsenic contamination in drinking water of Ardabil city in the Northwest of Iran.

Based on the environmental health assessment framework of the United State Environmental Protection Agency, a quantitative health risk assessment of arsenic in contaminated drinking water in a city in the northwest of Iran has been carried out. In the exposure assessment step, arsenic concentrations in drinking water were determined during four seasons. In addition, the water ingestion rate for different age groups in this region was determined. The concentration of arsenic in 163 collected samples from different locations during four seasons ranged from 0 to 99 µg L-1. Furthermore, a high percentage of the samples manifested higher levels than the permissible limit of 10 µg L-1. The total daily water intake rates of four age groups 1 to <2 (group 1), 2 to <6 (group 2), 6 to <16 (group 3), and ≥16 years (group 4) were estimated as 0.86, 1.49, 2.00, and 2.33 L day-1, respectively. Calculating the lifetime average daily dose of arsenic indicated that adults (group 4) had the highest and children (group 1) had the lowest daily intake of arsenic in their entire life. The results of risk characteristic showed that the order of excess lifetime cancer risk via arsenic exposure in the four groups was 4 > 3 > 2 > 1. The estimated risks for all age groups were higher than the acceptable range (1E-6 to 1E-4). The hazard quotient values for all of the classified groups were lower than the recommended limit values (<1), but it cannot be concluded that potential non-carcinogenicity risks are non-existent since the possible exposure to arsenic via food and skin may also pose the risk.

Predicting the capability of carboxymethyl cellulose-stabilized iron nanoparticles for the remediation of arsenite from water using the response surface methodology (RSM) model: Modeling and optimization.

This study aimed to investigate the feasibility of carboxymethyl cellulose-stabilized iron nanoparticles (C-nZVI) for the removal of arsenite ions from aqueous solutions. Iron nanoparticles and carboxymethyl cellulose-stabilized iron nanoparticles were freshly synthesized. The synthesized nanomaterials had a size of 10nm approximately. The transmission electron microscope (TEM) images depicted bulkier dendrite flocs of non-stabilized iron nanoparticles. It described nanoscale particles as not discrete resulting from the aggregation of particles. The scanning electron microscopy (SEM) image showed that C-nZVI is approximately discrete, well-dispersed and an almost spherical shape. The energy dispersive x-ray spectroscopy (EDAX) and X-ray diffraction (XRD) spectrum confirmed the presence of Fe0 in the C-nZVI composite. The central composite design under the Response Surface Methodology (RSM) was employed in order to investigate the effect of independent variables on arsenite removal and to determine the optimum condition. The reduced full second-order model indicated a well-fitted model since the experimental values were in good agreement with it. Therefore, this model is used for the prediction and optimization of arsenite removal from water. The maximum removal efficiency was estimated to be 100% when all parameters are considered simultaneously. The predicted optimal conditions for the maximum removal efficiency were achieved with initial arsenite concentration, 0.68mgL-1; C-nZVI, 0.3 (gL-1); time, 31.25 (min) and pH, 5.2.

Statistical analysis of arsenic contamination in drinking water in a city of Iran and its modeling using GIS.

In this research, probable arsenic contamination in drinking water in the city of Ardabil was studied in 163 samples during four seasons. In each season, sampling was carried out randomly in the study area. Results were analyzed statistically applying SPSS 19 software, and the data was also modeled by Arc GIS 10.1 software. The maximum permissible arsenic concentration in drinking water defined by the World Health Organization and Iranian national standard is 10 µg/L. Statistical analysis showed 75, 88, 47, and 69% of samples in autumn, winter, spring, and summer, respectively, had concentrations higher than the national standard. The mean concentrations of arsenic in autumn, winter, spring, and summer were 19.89, 15.9, 10.87, and 14.6 µg/L, respectively, and the overall average in all samples through the year was 15.32 µg/L. Although GIS outputs indicated that the concentration distribution profiles changed in four consecutive seasons, variance analysis of the results showed that statistically there is no significant difference in arsenic levels in four seasons.

National and sub-national drinking water fluoride concentrations and prevalence of fluorosis and of decayed, missed, and filled teeth in Iran from 1990 to 2015: a systematic review.

Fluoride intake, fluorosis, and dental caries could affect quality of life and disease burden worldwide. As a part of the National and Sub-national Burden of Disease Study (NASBOD) in Iran, we conducted a systematic review to evaluate province-year-specific mean drinking water fluoride concentrations and prevalence of fluorosis and of decayed, missed, and filled teeth (DMFT) in Iran from 1990 to December 2015. We did electronic searches of all English and Persian publications on PubMed, ScienceDirect, Google Scholar, and Iranian databases. Results revealed that the weighted mean drinking water fluoride concentration in Iran from 1990 to 2015 has been about 0.65 ± 0.38 mg/l. However, based on the WHO guideline value (1.50 mg/l) and the maximum permissible Iranian national fluoride standard (1.40 to 2.40 mg/l depending on the region's climate), there have been some regions in Iran with non-optimum fluoride concentrations in their drinking water (up to 7.0 mg/l). Overall, concentrations have been higher in southern parts of Iran and in some areas of Azerbaijan-e-Gharbi Province in the northwest and lower in the rest of the northwest and central parts of Iran. In addition, some hotspots have been found in Bushehr Province, southwest of Iran. The highest prevalence of dental flourosis has been reported in normal index while the lowest prevalence has been expressed in severe index. The lowest DMFT (about 0.1) was in Arsanjan City in Fars Province, and the highest (about 6.7) was for Najaf Abad City in Isfahan Province. Prevalence of fluorosis has been rather high in studied areas of Iran (e.g. 100 % in Maku City in Azarbaijan-e-Gharbi Province), and there was discrepancy for DMFT, but a lack of studies renders the results inconclusive. Further studies, health education and promotion plans, and evidence-based nutrition programs are recommended.

Effect of exposure to O3 , NO2, and SO2 on chronic obstructive pulmonary disease hospitalizations in Tabriz, Iran.

Air pollution in cities is a serious environmental problem especially in the developing countries. We examined the associations between gaseous pollutants and hospitalizations for chronic obstructive pulmonary diseases (COPD) among people living in Tabriz, a city in north western of Iran. We used the approach proposed by the World Health Organization (WHO) using the AirQ 2.2.3 software developed by the WHO European Center for Environment and Health, Bilthoven Division. To assess human exposure and health effect, data were used for ozone as a1h average; for nitrogen dioxide and sulfur dioxide as daily average concentrations. The association between air pollution and chronic obstructive pulmonary disease (COPD) was assessed using AirQ 2.2.3 model. The results of this study showed that 3 % (95 % CI 1.2-4.8 %) of HA COPD were attributed to O3 concentrations over 10 µg/m(3). Also, 0.9 % (95 % CI 0.1-2.2 %) and 0.4 % (95 % CI 0-1.1 %) of HA COPD were attributed to NO2 and SO2 concentrations over 10 µg/m(3), respectively. For every 10 µg/m(3) increase in O3, NO2, and SO2 concentrations, the risk of HA COPD increase to about 0.58, 0.38, and 0.44 %, respectively. We found significant positive associations between the levels of all air pollution and hospital admissions COPD. Otherwise, O3, NO2, and SO2 have a significant impact on COPD hospitalization.

Quality modeling of drinking groundwater using GIS in rural communities, northwest of Iran.

Given the importance of groundwater resources in water supply, this work aimed to study quality of drinking groundwater in rural areas in Tabriz county, northwest of Iran. Thirty two groundwater samples from different areas were collected and analyzed in terms of general parameters along with 20 heavy metals (e.g. As, Hg and …). The data of the analyses were applied as an attribute database for preparing thematic maps and showing water quality parameters. Multivariate statistical techniques, including principal component analysis (PCA) and hierarchical cluster analysis (CA) were used to compare and evaluate water quality. The findings showed that hydrochemical faces of the groundwater were of calcium-bicarbonate type. EC values were from 110 to 1750 µs/cm, in which concentration of salts was high in the east and a zone in north of the studied area. Hardness was from 52 to 476 mg/l and CaCO3 with average value of 185.88 ± 106.56 mg/L indicated hard water. Dominant cations and anions were Ca(2+) > Na(+) > Mg(2+) > K(+) and HCO3 (-) > Cl(-) > SO4 (2-) > NO3 (2), respectively. In the western areas, arsenic contamination was observed as high as 69 µg/L. Moreover, mercury was above the standard level in one of the villages. Eskandar and Olakandi villages had the lowest quality of drinking water. In terms of CA, sampling sites were classified into four clusters of similar water quality and PCA demonstrated that 3 components could cover 84.3% of the parameters. For investigating arsenic anomaly, conducting a comprehensive study in the western part of studied area is strongly recommended.

Removal of Arsenic (III, V) from aqueous solution by nanoscale zero-valent iron stabilized with starch and carboxymethyl cellulose.

In this work, synthetic nanoscale zerovalent iron (NZVI) stabilized with two polymers, Starch and Carboxymethyl cellulose (CMC) were examined and compared for their ability in removing As (III) and As (V) from aqueous solutions as the most promising iron nanoparticles form for arsenic removal. Batch operations were conducted with different process parameters such as contact time, nanoparticles concentration, initial arsenic concentration and pH. Results revealed that starch stabilized particles (S-nZVI) presented an outstanding ability to remove both arsenate and arsenite and displayed ~ 36.5% greater removal for As (V) and 30% for As (III) in comparison with CMC-stabilized nanoparticles (C-nZVI). However, from the particle stabilization viewpoint, there is a clear trade off to choosing the best stabilized nanoparticles form. Removal efficiency was enhanced with increasing the contact time and iron loading but reduced with increasing initial As (III, V) concentrations and pH. Almost complete removal of arsenic (up to 500 µg/L) was achieved in just 5 min when the S-nZVI mass concentration was 0.3 g/L and initial solution pH of 7 ± 0.1. The maximum removal efficiency of both arsenic species was obtained at pH = 5 ± 0.1 and starched nanoparticles was effective in slightly acidic and natural pH values. The adsorption kinetics fitted well with pseudo-second-order model and the adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 14 mg/g for arsenic (V), and 12.2 mg/g for arsenic (III). It could be concluded that starch stabilized Fe(0) nanoparticles showed remarkable potential for As (III, V) removal from aqueous solution e.g. contaminated water.