Providing predictive models for quality parameters of groundwater resources in arid areas of central Iran: A case study of kashan plain.

Groundwater pollution can occur due to both anthropogenic and natural causes, leading to a decline in water quality and posing a threat to human health and the environment. The pollution of ground water resources with chemical pollutants is often considered. To manage water resources sustainably, ensuring their quality and quantity is crucial. Yet, testing groundwater can be expensive and time-consuming. So, using modeling to predict the chemical parameters of groundwater resources is considered to be an efficient and economical method. In this study, we examined three models to predict groundwater quality in dry regions by using R programming language. The random forest (RF) outperformed the other models in developing predictive models for water quality. Also, the multiple linear regression (MLR) model demonstrated strong performance, particularly in predicting total hardness (TH) in Aran Va Bidgol groundwater resources. The decision tree (DT) model did well but had lower performance than the RF model in predicting quality parameters. This approach can be efficacious in the field of effective management and protection of groundwater resources and enables the assessment of risks related to water resources.

Removal of most frequent microplastic types and sizes in secondary effluent using Al2(SO4)3: choosing variables by a fuzzy Delphi method.

Microplastics (MPs) as an emerging pollutant can affect aquatic organisms through physical ingestion, chemical problems and possible creation of biological layers on their surfaces in the environment. One of the significant ways for MPs to enter the aquatic environment is through the effluent discharge of wastewater treatment plants (WWTPs). In this study, first, the concentration and characteristics of MPs in secondary wastewater effluent, and the influential variables related to the coagulation process, for MPs removal were identified using systematic reviews of previous studies. Then, the most proper MPs characterization and coagulation variables were chosen by experts' opinions using a fuzzy Delphi method. Therefore, the experiment tested in conditions close to the full-scale wastewater treatments. Finally, in the laboratory removal of MPs by coagulation of polyamide (PA), polystyrene (PS), and polyethylene (PE), < 125 and 300-600 µm in size, was tested by a jar test applying Al2(SO4)3 in doses of 5 to 100 mg/L plus 15 mg/L polyacrylamide as a coagulant aid. Using R and Excel software, the results were analyzed statistically. It was concluded that the maximum and minimum removal efficiency was 74.7 and 1.39% for small PA and large PE, respectively. Smaller MPs were found to have higher removal efficiency. The MPs type PA achieved greater removal efficiency than PS, while PE had the least removal efficiency.

Radon measurement and age-independent effective dose attributed to ingestion of bottled water in Iran: sensitivity analysis.

A comprehensive study was made to measure the radon concentration in bottled water available in Iran market. The 222Rn concentration in 70 bottled water samples were measured by the sniffing mode technique and RTM 1688-2 (SARAD, Germany) in immediate sampling time and 3 months later for determination of radon decay. The measured radon concentration ranged from 0.003 to 0.618 Bq L-1 in bottled water samples, which were much lower than the recommended value for radon in drinking water by WHO (100 Bq L-1) and United states environmental protection agency (USEPA) (11.1 Bq L-1). The annual effective dose of 222Rn due to ingestion bottled water was also evaluated in this research. The mean annual effective dose due to ingestion of radon in bottled water for adults, children, and infants were estimated to vary from 5.30 × 10-4 mSv-1, 4.90 × 10-4 mSv-1, and 2.15 × 10-4 mSv-1, respectively. Overall, this study indicated that the Iranian people receive no significant radiological risk due to exposure to radon concentration in bottled water brands common consumed in Iranian market.

Prediction models for groundwater quality parameters using a multiple linear regression (MLR): a case study of Kermanshah, Iran.

Groundwater is one of the major sources of exploitation in arid and semiarid regions. Spatial and temporal quality distribution is an important factor in groundwater management. Thus for protecting groundwater quality, data production on spatial and temporal distribution is essential. The present study has applied multiple linear regression (MLR) techniques to predict the fitness of groundwater quality in Kermanshah province, west of Iran. The parameters examined were Total dissolved solids (TDS), Total hardness (TH), Sodium adsorption ratio (SAR). the quality variables were modelled by MLR. Finally, the performance of the models was assessed using the coefficient of determination (R2). The relationship between parameters by MLR showed that TDS and water quality parameters in semi-deep wells and aquifers had a strong positive correlation (r = 0.94, r = 0.98) and there was a strong positive significant correlation between SAR and water quality parameters in deep wells and aquifers (r = 0.98, r = 0.99). Also, TH and water quality parameters in all water sources had a strong positive correlation (r = 1). The MLR model could serve as an alternative and cost-effective tool for groundwater quality prediction where there is limitation in laboratory facilities, trained expertise or time. Consequently, the usefulness of these linear regression equations in predicting the groundwater quality is an approach, which can be applied in any other locations.

Polycyclic aromatic hydrocarbons (PAHs) in meat, poultry, fish and related product samples of Iran: a risk assessment study.

Meat, poultry, and seafood such as fish are a valuable source of protein, vitamins and minerals. Considering their high consumption in the human diet, it is necessary to study pollutants (such as PAHs) in them. This present study has focused on the PAHs level and probabilistic risk of health in meat, poultry, fish and related product samples by MSPE-GC/MS technique (magnetic solid-phase extraction with gas chromatography-mass spectrometry). The maximum mean of 16 PAH was detected in smoked fish samples (222.7 ± 13.2 µg/kg) and the minimum mean of 16 PAH was detected in chicken (juje) kebab (112.9 ± 7.2 µg/kg µg/kg). The maximum mean of 4PAHs was detected in tuna fish (23.7 ± 2.4 µg/kg) and the minimum mean of 4PAHs was seen in grilled chicken and sausage samples (non-detected). Our results showed the 4PAHs and B[a]P were lower than the EU (European Union) standard levels (these standard levels were 30 and 5 µg/kg, respectively). Furthermore, the correlation among the type and concentrations of PAHs congeners was investigated through cluster analysis by heat map and principal component analysis. The 90th percentile ILCR (incremental lifetime cancer risk) of PAH compounds in fish, poultry, meat and related products samples was 3.39E-06, which was lower than the maximum acceptable level of risk (10-4). Finally, the highest ILCR was related to hamburger (4.45E-06). Therefore, there is no risk in consuming these foods in Iran, but it is necessary to monitor PAHs concentration in different types of foods.

Quantitative microbial risk assessment of enteroviruses in raw-eatable vegetables irrigated by wastewater: examining different scenarios of washing.

Due to the increasing water crisis, the reuse of wastewater deserves attention as a method to reduce the pressure of the water crisis, especially in developing countries. The application of health risk assessment models is a way to estimate disease burdens associated with crop irrigation by wastewater effluents. In this study, a quantitative microbial risk assessment (QMRA) with probabilistic Monte-Carlo simulation was used to estimate the annual risk of enteroviruses (EVs) infection and disease burden for consumers of effluent-irrigated raw vegetables in Tehran, the capital of Iran. Wastewater effluent samples were collected over two seasons: summer and winter. EVs were analyzed in three stages, concentration and separation, cell culture, and real-time PCR (RT-PCR). A questionnaire was used to determine the dominant patterns of vegetable washing by consumers. There were 4 vegetable washing steps: wiping away mud (A), rinsing (B), using detergents (C), using disinfectants (D). 5 patterns of washing were examined in the laboratory and the concentration of enteroviruses was measured in every pattern. pattern 1: just wiping away mud (A), pattern 2: wiping away mud and rinsing (AB), pattern 3: wiping away mud by using detergents and rinsing (ABCB), pattern 4: wiping away mud by using disinfectants and rinsing (ABDB), and pattern 5: wiping away mud by using detergents and disinfectants and rinsing (ABCBDB). For washing pattern 1, pattern 2, and pattern 3, the estimated annual infection risk of EVs was estimated to be 5.6 × 10-1, 3.6 × 10-1, 1.7 × 10-1 (risk/per.day), and burden of disease was calculated as 3 × 10-2, 2 × 10-2, and 9 × 10-3 (burden/year), respectively. The results showed that if vegetables are washed according to method 5, the microbial risk will be minimized and the excess prevalence of viral infections will be eliminated.

Effects of respirators to reduce fine particulate matter exposures on blood pressure and heart rate variability: A systematic review and meta-analysis.

Particulate-filtering respirators (PFRs) have been recommended as a practical personal-level intervention to protect individuals from the health effects of particulate matter exposure. However, the cardiovascular benefits of PFRs including improvements in key surrogate endpoints remain unclear. We performed a systematic review and meta-analysis of randomized studies (wearing versus not wearing PFRs) reporting the effects on blood pressure (BP) and heart rate variability (HRV). The search was performed on January 3, 2022 to identify published papers until this date. We queried three English databases, including PubMed, Web of Science Core Collection and Scopus. Of 527 articles identified, eight trials enrolling 312 participants (mean age ± standard deviation: 36 ± 19.8; 132 female) met our inclusion criteria for analyses. Study participants wore PFRs from 2 to 48 h during intervention periods. Wearing PFRs was associated with a non-significant pooled mean difference of -0.78 mmHg (95% confidence interval [CI]: -2.06, 0.50) and -0.49 mmHg (95%CI: -1.37, 0.38) in systolic and diastolic BP (SBP and DBP). There was a marginally significant reduction of mean arterial pressure (MAP) by nearly 1.1 mmHg (95%CI: -2.13, 0.01). The use of PFRs was associated with a significant increase of 38.92 ms2 (95%CI: 1.07, 76.77) in pooled mean high frequency (power in the high frequency band (0.15-0.4 Hz)) and a reduction in the low (power in the low frequency band (0.04-0.15Hz))-to-high frequency ratio [-0.14 (95%CI: -0.27, 0.00)]. Other HRV indices were not significantly changed. Our meta-analysis demonstrates modest or non-significant improvements in BP and many HRV parameters from wearing PFRs over brief periods. However, these findings are limited by the small number of trials as well as variations in experimental designs and durations. Given the mounting global public health threat posed by air pollution, larger-scale trials are warranted to elucidate more conclusively the potential health benefits of PFRs.

Evaluation of conventional wastewater treatment plants efficiency to remove microplastics in terms of abundance, size, shape, and type: A systematic review and Meta-analysis.

In the present study Web of Science, Scopus, and PubMed as electronic databases were used to find work published up to October 27, 2020 about microplastics evaluation in conventional wastewater treatment plants. In total, 407 publications were found, of which 77 were eligible for meta-analysis. A comprehensive meta-analysis was undertaken to evaluate the relevant publications regarding microplastics abundance. The average microplastics abundance was within the 1-31,400, 0.2-12,580, 0.002-7863, and 0.003-447 items range per liter wastewater for influent, primary, secondary, and tertiary treatment steps, respectively. The difference between the abundance of microplastics characterization for the different treatment steps was analyzed using ANOVA or Kruskal-Wallis test (depending on the data distribution). According to the pooled data, the average microplastics abundance was 124.04, 20.67, 5.62, and 1.97 (items/l) for influent, primary, secondary, and tertiary treatment. The results of Egger's test (t = 7.49, P ≤ 0.0001) were statistically significant, suggesting the existence of publication bias.

The analysis and probabilistic health risk assessment of polycyclic aromatic hydrocarbons in cereal products.

The analysis and probabilistic health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in cereal products were done by using magnetic solid-phase extraction (MSPE) method and gas chromatography/mass spectrometric (GC/MS). The results of method showed LOQ and LOD of PAHs compounds were 0.105-0.180 and 0.035-0.060 µg/kg, and the recorded values were 4.3-12.1 and 6.1-20.3% for repeatability and reproducibility with an estimated recovery of 94.4-103.4%. In this study, we analyzed kind of bread (Barbari, Sangak, Baguette, Taftoon, Lavash), macaroni, lasagna, and cooked rice that mean of total PAHs were 98.2, 121.7, 134.9, 166.3, 176.3, 176.2, 130.1, and 248.3 µg/kg, respectively. Further, the correlation between the type and amount of 16 PAHs with cereal products samples evaluated with multivariate principal component analysis and heat map visualization. The highest incremental lifetime cancer risk (ILCR) was found in cooked rice (7.80E-6), while the lowest ILCR was found in Lasagna (2.35E-07). In conclusion, the PAHs content in the tested products were in low health risk ranges (1 × 10-6 < ILCR < 1 × 10-4), and all of the cereal products sold in Tehran are considered safe for consumers. Therefore, cereal products should be regularly evaluated and monitored by regulatory agencies to reduce contaminants in these high-consumption products.

Cardiovascular health effects of wearing a particulate-filtering respirator to reduce particulate matter exposure: a randomized crossover trial.

This randomized crossover trial sought to determine whether wearing a high-efficiency particulate-filtering respirator (PFR) improves cardiovascular function over 48 h among healthy college students in Tehran. This trial was conducted from February 14th to 23rd, 2019 and twenty-six participants completed two 48-h intervention periods. Brachial blood pressure (BP) measured by 24-h ambulatory monitoring was the primary health outcome. Secondary outcomes included 48-h heart rate variability (HRV) indices, high-sensitive cardiac troponin (hs-TnT) and other biomarkers. The participants wore the PFR between 10.2 and 11.1 h while awake during the interventions. More than 80% of participants reported increased respiratory resistance while wearing the PFR due to a lack of an exhalation valve. There were no significant differences in brachial BP levels between subjects who wore PFR respirator and those did not. Except for high frequency (HF) power and heart rate (HR), no significant differences between interventions were observed for other HRV metrics. Wearing the PFR led to an increase of 66.0 ms2 (95% confidence interval [CI], 9.6-110.5) and 79.6 ms2 (95% CI, 19.0-140.1) in HF power during the first day when the two groups of participants wore the PFR. Night-time HR was significantly increased during the PFR intervention period. Other secondary outcomes were not significantly different between interventions. It is plausible that incomplete exposure reduction due to wearing the PFR less than half of the time or increased respiratory resistance mitigated potential health benefits. Additional trials are warranted to validate the CV protection of wearing PFRs in heavily-polluted cities.

Monitoring of caffeine concentration in infused tea, human urine, domestic wastewater and different water resources in southeast of Iran- caffeine an alternative indicator for contamination of human origin.

The present study was developed to evaluate the caffeine concentration in commercially high-consumed brands of dry black tea, urine of tea consumers, raw and treated wastewater, as well as water resources (WRs) in Zabol city, Iran. Furthermore, a complementary analysis was performed to evaluate the relationship between caffeine content and total coliform (TCF) and Escherichia coli (E. coli) in water sources. In this end, tea (90 samples), urine (90 samples), raw sewage (72 samples), treated sewage (72 samples), and septic tank sewage (36samples) were taken from Zabol city and analyzed in terms of caffeine content. To evaluate the correlation between caffeine and TCF and E. coli, 102 water samples were taken from WRs in Zabol city. Caffeine was measured by high-performance liquid chromatography (HPLC). Furthermore, TFC and E. coli were measured based on the procedure outlined by standard methods for water and wastewater examination and the most probable number (MPN) method. The results indicated that the caffeine concentration in different tea brands consumed by Zabol people were in the range of 12.35-18.75 mg/L. The mean caffeine level in the male group' urine (7.08 ± 1.00 µg/mL) was significantly higher than the female group (4.83 ± 1.94 µg/mL). The results showed that the total average amount of caffeine in raw and treated wastewater in Zabol city was 21.04 ± 2.22 and 19.86 ± 2.08 µg/L, respectively. Besides, the caffeine removal efficiency by the Zabol wastewater treatment plant (ZWTP) was found to be between 4.79 and 51.39%. According to the results, the environmental risk associated with caffeine through the discharge of raw and treated wastewater from ZWTP into receiving WRs was estimated to be less than the allowable limit (RQ = 1). The results showed that caffeine could be an indicator for fecal contamination with human origin.

A Comparative Survey on Antioxidant Activity of Iranian Shrimp Waste (Penaeus semisulcatus) and Synthetic Antioxidants.

BACKGROUND: Shrimp waste, as an important source of natural carotenoids, is produced in large quantities in the seafood processing industry. One of the important characteristics of carotenoids is their ability to act as antioxidants, thus protecting cells and tissues from the damaging effects of free radicals and singlet oxygen. AIMS: The aim of this study was to find an effective method for carotenoid extraction (Enzymatic and alkaline treatment) from shrimp waste and compare their antioxidant potential with synthetic antioxidants butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) using sunflower oil. METHODS: The sunflower oil was exposed to three concentrations of extracted carotenoid (470, 235, and 118 mg/kg) and synthetic antioxidants. The inhibition of lipid peroxidation was evaluated for Malondialdehyde and peroxide value. RESULTS AND DISCUSSION: The mean values of carotenoid extract were 243 and 170 mg/kg for enzymatic and alkaline treatment, respectively. Therefore, the highest efficacy of carotenoid extraction was obtained from enzymatic extraction. The oil samples containing 470 ppm carotenoid, which were extracted by alcalase as the default treatment, exhibited a less peroxide value and higher antioxidant potential than the oil samples containing synthetic antioxidants. CONCLUSION: According to the results, the synthetic antioxidants can be replaced by extracted carotenoids from shrimp waste as a natural antioxidant to inhibit oxidation.

Human health and ecological risk assessment of heavy metal(loid)s in agricultural soils of rural areas: A case study in Kurdistan Province, Iran.

BACKGROUND: Agricultural soils pollution with heavy metal (loid) s (HMs) can create significant ecological and health problems. The aims of present study were to characterize HMs pollution profile of dry farmland soils in rural areas of Kurdistan province in Iran and evaluate potential associated ecological and health risks. METHODS: Different indices of Geo-accumulation index (IGeo), Individual contamination factor (ICF), Nemerow composite pollution index (NCPI) and Potential Ecological Risk Index (PERI) were employed to assess the bio-accumulation of the HMs and evaluate associated ecological risks. Human health risks estimated with total hazard index (THI) and total carcinogenic risk (TCR) indices based on ingestion, inhalation and dermal exposure pathways for children and adults. RESULTS: As, Cd, Cr, Ni and Pb exceeded the soil standards. The spatial maps of the IGeo showed that As pollution was at severe level in eastern part of the study region. According to the ICF results, the studied soils were extremely contaminated with As, Cd, Cr, Ni and Zn. Furthermore, based on the pollution indices, some of sampling sites were critically polluted by abovementioned HMs. For children and adults groups, the THI values in 13 and 97% of sampling sites were more than 1 and the TCR in 7 and 14% of sampling sites were more than 10-4, respectively. The farmland soil pollution of the study area by As and Cr were found to be quite serious and dangerous. CONCLUSION: The findings of this study suggest that further attention should be paid by decision-makers to control the HMs pollution in the agricultural soils of the study area.

The concentration of BTEX compounds and health risk assessment in municipal solid waste facilities and urban areas.

In this study, human exposure to benzene, toluene, ethylbenzene, xylenes (BTEX), along with their respective risk assessment is studied in four major units (n = 14-point sources) of the largest municipal solid waste management facilities (MSWF) in Iran. The results were compared with four urban sites in Tehran, capital of Iran. Workers at the pre-processing unit are exposed to the highest total BTEX (151 µg m-3). In specific, they were exposed to benzene concentrations of 11 µg m-3. Moreover, the total BTEX (t-BTEX) concentrations measured over the conveyor belt was 198 µg m-3 at most, followed by trommel (104), and active landfills (43). The mean concentration of ambient t-BTEX in Tehran is 100 µg m-3. On average, xylenes and toluene have the highest concentrations in both on-site and urban environments, with mean values of 24 and 21, and 41 and 37 µg m-3, respectively. Even though the non-carcinogenic risk of occupational exposure is negligible, BTEX is likely to increase the chance of carcinogenic risks (1.7E-05) for workers at the pre-processing unit. A definite carcinogenic risk of 1.3E-04, and non-carcinogenic effect, of HI = 1.6 were observed in one urban site. With the exception of the pre-processing unit, the citizens of Tehran had higher exposure to BTEX. Overall, BTEX concentrations in the largest MSWF of Iran remains an issue of public health concern.

Can respirator face masks in a developing country reduce exposure to ambient particulate matter?

Respirator face masks (RFMs) as a personal-level intervention is increasingly being utilized to reduce ambient particulate matter (PM) exposure, globally. We tested the effectiveness of 50 commercially available ones in reducing the exposure of ambient particle number concentrations (PNC), PM10, PM2.5, and PM1 (PM ≤ 10, 2.5, and 1 µm in diameter, respectively) in a traffic-affected urban site in Tehran. To examine the efficiency of RFMs, we applied a specific experimental setup including vacuum pumps, dummy heads, connecting tubes, glass chambers, and GRIMM Aerosol Spectrometer to measure all metrics after dummy heads. The average effectiveness of RFMs was in the range of 0.7-83.5%, 3.5-68.1%, 0.8-46.1%, and 0.4-32.2% in reducing ambient PNC, PM10, PM2.5, and PM1, respectively. Considering all metrics, the highest effectiveness was observed always for Biomask, followed by 3 M 9332, due to their well-designed physical characteristics (e.g., adjustable nose clip for any face/nose shape, and size, soft inner material in the nose panel to provide a secure seal against leakage, adjustable or elasticated straps/ear loops to better adjust on any face). Biomask reduced ambient PM10 with a mean value of 94.6 µg m-3 (minimum-maximum: 51.7-100.3 µg m-3), whereas it filtered on average just 29.0 µg m-3 (25.7-43.5 µg m-3) of ambient PM2.5 and 18.2 µg m-3 (14.7-21.8 µg m-3) of PM1. A fuzzy analytical hierarchy process to find the most important design-related factors of RFMs affecting their effectiveness, which showed the exhalation valve and its diaphragm (20.4%), nose clip (19.7%), and cheek flaps (18.6%) are ranked as the main design-related variables. The fuzzy technique for order preference by similarity to ideal solution indicated that Biomask and 3M 9332 had scores of 1 and 0.97, the highest scores compared with other RFMs. This study provides crucial evidence-based results to elucidate the effectiveness and design-related factors of RFMs in real-environmental circumstances.

Prenatal urinary concentrations of environmental phenols and birth outcomes in the mother-infant pairs of Tehran Environment and Neurodevelopmental Disorders (TEND) cohort study.

Daily exposure to environmental phenols can lead to potential undesirable effects on the health of pregnant women and fetuses. The present study is aimed to evaluate the relationship between maternal urinary concentrations of phenols in pregnancy and anthropometric birth outcomes. The studied population comprised of 189 pregnant women participating in the Tehran Environment and Neurodevelopmental Disorders (TEND) prospective cohort study, which had been ongoing since March 2016 in some hospitals and health care delivery centers in Tehran, Iran. Concentrations of bisphenol-A, triclosan, 4-nonylphenol, and parabens were determined in spot urine samples of pregnant mothers in the first trimester. Weight, length, and head circumference at birth were also extracted from the mothers' delivery files. Multivariable linear regression was used to examine the relationship between log-concentrations of phenols and birth outcomes. When we analyzed all samples regardless of neonates' gender, none of the urinary concentrations of phenols were associated with weight and length at birth. Indeed, in sex-stratified adjusted models, one log-unit increase of butylparaben was related to a 283.6 g (95% CI: 23, 544) increase in boys' birth weight. Prenatal urinary concentration of triclosan and propylparaben was respectively related to a decrease of 4.8 cm (95% C: -8.5, -1.1) in boys' length and 0.9 cm (95%CI: -1.8, -0.04) in girls' length. In the adjusted models for estimating the changes in head circumference, one log-unit increase of triclosan, methylparaben, and butylparaben led to a reduction of 1.6 cm (95% CI: -3.17, 0.03), increase of 0.8 cm (95% CI: -0.01, 1.6) and 0.7 cm (95% CI: 0.08, 1.4) in head circumference at birth respectively. Our results suggested that prenatal triclosan and parabens exposure might be associated with head circumference at birth. Furthermore, we observed a sexually dimorphic pattern between maternal triclosan and parabens exposure during pregnancy and fetal growth. However, these findings must be interpreted while taking into account the limitations of this study.

Landfill site selection using a hybrid system of AHP-Fuzzy in GIS environment: A case study in Shiraz city, Iran.

Landfilling with simplicity and economic advantages is the most common element for waste management in both developed and developing countries. Landfill site selection in a proper way is an important municipal planning process which prevent environmental issues including water pollution imposed for insanitary landfills. The present research was developed to exhibit a simplified method of multi criteria decision making (MCDM) and Fuzzy memberships in GIS environment to ascertain best landfill sites for Shiraz county, located south of Iran. 15 most common sub-criteria, documented in literature and implicated by Iranian environmental protection organization (IEPO) including surface water, ground water, land use, distance to well, soil type, slope, protected area, fault in environmental group, residential area, road, airport, village, infrastructure, historical area, wind direction in socio-economical group were selected and the weight of each criterion was determined based on expert's knowledge with use of analytical hierarchy process (AHP). The results of the present research are as follows: •Distance to residential area and groundwaters with weight of 0.36 and 0.28 were recognized as the most important criteria for landfill site selection.•The six suitable areas for landfill in Shiraz county is 1.003% of total area equal to 8710 ha.•AHP and Fuzzy memberships has a great potential and ability for landfill site selection.

Propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR) assay for rapid detection of viable and viable but non-culturable (VBNC) Pseudomonas aeruginosa in swimming pools.

Lack of culturability in the viable but non-culturable (VBNC) bacteria and the ability to regain infectivity in favourable conditions is one of the new challenges of public health providers for Pseudomonas aeruginosa monitoring in environmental samples. Propidium monoazide quantitative polymerase chain reaction (PMA-qPCR) is one of the promising methods for timely detection of VBNC pathogens in environmental samples. We developed and used a method for the first time to detection of VBNC P. aeruginosa in swimming pool water samples using a membrane filter (MF). Moreover, the dominant model of the distribution of colonies on the MF and the effect of the culture medium and MF type on colony recovery by MF were evaluated. Swimming pool samples were subjected to conventional culture-based, qPCR and PMA-qPCR methods and the results were compared for the presence of VBNC P. aeruginosa in the samples. The positivity rate was 21% and 75% for P. aeruginosa in water samples as confirmed by standard culture-based and qPCR methods, respectively. Furthermore, of 24 samples, 9 (37.5%) were positive for VBNC P. aeruginosa. The developed qPCR/PMA-qPCR assay can detect the VBNC bacteria directly from aquatic samples and may result in better monitoring of recreational waters.

Chemical composition of PM10 and its effect on in vitro hemolysis of human red blood cells (RBCs): a comparison study during dust storm and inversion.

PURPOSE: This study aimed to investigate chemical composition of PM10 (particulate matter with aerodynamic diameter ≤ 10 µm) during dust storm and inversion in Tehran and hemolysis effects. METHODS: PM10 was sampled in Tehran, Iran, during dust storm and inversion conditions. Water soluble ions (F¯, Cl¯, NO2¯, NO3¯, SO4¯2, Na+, K+, NH4 +, Ca+2, Mg+2) and elements (Al, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Se, Sn, Sr, V, Zn, Pt, Rh, Pd, As and Si) were analyzed by ion chromatograph (IC) and inductively coupled plasma optical emission spectrometer (ICP-OES), respectively. Hemolysis was examined as in vitro at PM10 concentrations of 50-300 µg/ml. RESULTS: Daily average of PM10 concentrations in dusty and inversion days were 348.40 and 220.54 µg/m3, respectively. Most prevalence ionic components were NO3¯, Cl¯, SO4¯2 and Ca+2 during dust storm and SO4¯2, NO3¯, Cl¯ and NH4 + during inversion. Si, Fe and Al had the maximum values in both conditions. Particles associated with both conditions induced hemolytic responses. PM10 from dusty day showed a higher hemolysis percent (10.24 ± 4.67%) than inversion (9.08 ± 5.47%), but this difference was not significant (p = 0.32). Hemolytic effects were significantly intensified by increased PM concentrations (p < 0.001) in a dose-response manner. CONCLUSIONS: As the results, chemical composition of sampled particles from inversion days and dust storm was different from each other. Hemolytic effects of particles during dust storm were more than inversion days. However, this difference was not statistically significant.

Optimizing the performance of conventional water treatment system using quantitative microbial risk assessment, Tehran, Iran.

The performance of conventional drinking water treatment plants (WTPs) can be improved using quantitative microbial risk assessment (QMRA). A QMRA study on Cryptosporidium using actual pathogen density was conducted to examine the performance of Jalaliyeh WTP in Tehran, Iran. The infection risk and the burden of disease attributed to the parasite presence in finished water were estimated incorporating physical and chemical log reduction values (LRVs), using stochastic modeling and disinfection profiling. The risk and burden of disease were compared with health-based targets, i.e. one case of infection per 10,000 people or 10-6 DALYs per person per year. The parasite's LRVs were 2.31 and 0.034 log provided by physico-chemical treatment and disinfection processes, respectively. The mean of estimated risk (111 cases per 104 people per year) and the burden of disease (11.7 DALYs per 106 people per year) both exceeded the targets. To control the excess risk, three QMRA-based disinfection scenarios were examined including: (1) employing chlorine dioxide (ClO2) instead of chlorine (2) ozonation with a concentration of 0.75 mg/L (Ct = 22.5 min mg/L) and (3) UV irradiation with a dose of 10 mJ/cm2. The LRV of parasite may be increased to 3.0, 5.1 and 4.9 log by employing ClO2, ozonation and UV irradiation, respectively. The use of ozone or UV as alternative disinfectants, could enhance the disinfection efficacy and provide sufficient additional treatment against the excess risk of parasite. QMRA could make it easier applying appropriate improvement to conventional WTPs in order to increase the system performance in terms of health-based measures.