A study of Polycyclic Aromatic Hydrocarbons (PAHs) and Trace Elements in Ambient air PM2.5 in an Urban Site of Tehran, Iran

The concentrations of thirteen polycyclic aromatic hydrocarbons (PAHs) and six trace elements adsorbed to a fine fraction of particulate matter (PM ≤ 2.5 µm) were determined at an urban site in Tehran (Iran) during the spring period in 2013. The average concentration of PM2.5 was 41.19 µg/m3, which was 1.64 and 1.2 times higher than the annual average of WHO guidelines and EPA ambient air quality standards, respectively. The trace elements measured in the PM2.5 samples were Pb, Cd, Cr, Ni, As and Zn with the mean concentrations of 38.05, 18.2, 4.24, 4.19, 1.34, and 69:92 ng/m3 respectively. Hg wasnot found in any sample in this study. Results from correlation tests between PM2.5 concentrations and different toxic metals; which were studied in various days of the week, including holidays, 1 day after the holidays, and the other days showed that the variability between groups were significant at the 0.05 level. Exception is Hg and Zn. The mean concentrations of PM2.5 and trace elements in 1 day after the holidays were higher compared other 2 groups. Total PAHs concentrations in PM2.5 were found to be 7.92 ng/m3.The most abundant PAHs found were high molecular weight homologues (4-6 ring PAHs) such as Inp, Bgp, Dba, Bkf and Bbf, which are contributing to constituents of vehicular emissions. In general, high molecular weight PAHs are more correlated than low molecular weight PAHs. Moreover a moderate correlation was observed between total PAH concentration and PM2.5 mass

Assessment of sediment quality based on acid-volatile sulfide and simultaneously extracted metals in heavily industrialized area of Asaluyeh, Persian Gulf: concentrations, spatial distributions,and sediment bioavailability/toxicity

Sediment samples from the coastal area of Asaluyeh harbor were collected during autumn and spring 2015. The acid-volatile sulfide (AVS) and simultaneously extracted metals (SEMs) were measured to assess the sediment quality and potential ecological risks. The average concentrations (and relative standard deviation (RSD)) of AVS in the industrial sediments were 12.32 μmol/g (36.91) and 6.34 μmol/g (80.05) in autumn and spring, respectively, while in the urban area, these values were 0.44 μmol/g (123.50) and 0.31 μmol/g (160.0) in autumn and spring, respectively. The average concentrations of SEM (and RSD) in the industrial sediments were 15.02 μmol/g (14.38) and 12.34 μmol/g (20.65) in autumn and spring, respectively, while in the urban area, these values were 1.10 μmol/g (43.03) and 1.06 μmol/g (55.59) in autumn and spring, respectively. Zn was the predominant component (34.25–86.24 %) of SEM, while the corresponding value for Cd, much more toxic ingredient, was less than 1 %. Some of the coastal sediments in the harbor of Asaluyeh (20 and 47 % in autumn and spring, respectively) had expected adverse biological effects based on the suggested criterion by United States Environmental Protection Agency (USEPA), while most stations (80 and 53 % in autumn and spring, respectively) had uncertain adverse effects

The effect of climate change on cholera disease: The road ahead using artificial neural network.

Climate change has been described to raise outbreaks of water-born infectious diseases and increases public health concerns. This study aimed at finding out these impacts on cholera infections by using Artificial Neural Networks (ANNs) from 2021 to 2050. Daily data for cholera infection cases in Qom city, which is located in the center of Iran, were analyzed from 1998 to 2016. To determine the best lag time and combination of inputs, Gamma Test (GT) was applied. General circulation model outputs were utilized to project future climate pattern under two scenarios of Representative Concentration Pathway (RCP2.6 and RCP8.5). Statistical downscaling was done to produce high-resolution synthetic time series weather dataset. ANNs were applied for simulating the impact of climate change on cholera. The observed climate variables including maximum and minimum temperatures and precipitation were tagged as predictors in ANNs. Cholera cases were considered as the target outcome variable. Projected future (2020-2050) climate in previous step was carried out to assess future cholera incidence. A seasonal trend in cholera infection was seen. Our results elucidated that the best lag time was 21 days. According to the results of downscaling tool, future climate in the study area by 2050 will be warmer and wetter. Simulation of cholera cases indicated that there is a clear trend of increasing cholera cases under the worst scenario (RCP8.5) by the year 2050 and the highest cholera cases observe in warmer months. The precipitation was recognized as the most effective input variable by sensitivity analysis. We observed a significant correlation between low precipitation and cholera infection. There is a strong evidence to show that cholera disease is correlated with environment variables, as low precipitation and high temperatures in warmer months could provide the swifter bacterial replication. These conditions in Iran, especially in the central parts, may raise the cholera infection rates. Furthermore, ANNs is an executive tool to simulate the impact of climate change on cholera to estimate the future trend of cholera incidence for adopting protective measures in endemic areas

Effect of Ozonation and Hydrogen Peroxide on Reducing the Volume and Chemical Oxygen Demand of Waste Water Treatment Plants Sludge

Background: Ozonation decays solids and accelerates their consolidation due to strong oxidation capability; hence, decreasing the problems and expenses of equipment and operating the sludge digestion and disposal. In this study, we aimed to investigate the effect of separate and combined effects of ozone and hydrogen peroxide in reducing contamination volume. Methods: Sludge ozonation was conducted with concentrations of 0.0557 to 0.5573mg O3/mgTSS5573 from 5 to 50 min. Total suspended solids (TSS), volatile solids (VS), chemical oxygen demand (COD) parameters, soluble COD, and the sludge settleability were investigated before and after the process. Results: The results demonstrated that after 50 min of ozonation and injection of mgO3/mg TSS 0.3901 ozone, sludge volume reduction reached 42%. Furthermore, after 50 minutes of ozonation, TSS and VS with a 43% and 48% reduction, reached to 4261mg/l and 3193mg/l, respectively. Total COD after 35 min of ozonation decreased 39% from 12524mg/l to 7639mg/l. Also injection of 6ml of hydrogen peroxide (30%) leading to a reduction in TSS and VS by 64 and 65%, respectively, and injection of 4ml of it, resulting in a 58% reduction in COD and 75% in the volume of sedimented sludge. The effect of the combination of ozone and hydrogen peroxide resulted in the reduction of only 10% of sedimented sludge volume and also reduced removal of COD by 42%. Conclusion: According to the results, ozone and hydrogen peroxide injection to sludge, decrease sludge volume, improve in sedimentation and reduce the pollution load at the level of standar

Study of Concentrations and Risk Assessment of Heavy Metals Resulting From the Consumption of Agriculture Product in Different Farms of Dayyer City, Bushehr

Background: Accumulation of heavy metals and increasing their concentration and reaching them to the danger range can threaten human health by entering to food chain. Thus, continuous monitoring of pollutants consentration in agricultural products is important. So, the aim of this study was to investigate the heavy metals concentration and risk assessment resulting from them in agriculture product with two types of irrigation in farms of Dayyer city which is one of the counties in Boushehr province. Material and Methods: Samples of agriculture product were harvested in three in three categories vegetables included: leafy (lettuce, spinach, cabbage), tuber (onion, potato), and fruit (tomato, green pepper) from farms of Dayyer city with two types of irrigation included River Water Irrigation (RWI( and Ground Water Irrigation (GWI). Totally 320 samples were analyzed by using (ICP-OES -Spectrum Arcos) after acidic digestion steps and extraction of heavy metals from samples. Then, the obtained results were analyzed by diffrent equations and statistic softwares. Results: results showed that the concentrations of metals were 68.75 (47.71), 277.62 (196.12), 32.68 (18.31), 42.19 (17.09), 1.76 (0.87) and 12.04 (5.83) mg kg-1 for Zn, Mn, Cu, Cr, Cd and Pb in RWI (and GWI), respectively in irrigated farms with river water (farms irrigated by ground water). The concentration of heavy metals was significantly higher in the soil of farms which irrigated with river water than those which irrigated with ground water (P<0.05). Also, results showed that in farms which irrigated by ground water, the highest Target hazard quotient (THQ) have been reported in spinach with mentioned values; Zn (0.1150), Cd (1.2846), Cu (0.2030) and Pb (1.9141). Conclusion: The findings of this study showed that the concentration of heavy metals in soil and agricultural products which irrigated with contaminated water with urban and industrial sewage was higher than soil and agricultural productswhich irrigated with ground water. Also results of this study showed that the hazard for consumers health in agricultural products that were irrigated with water contaminated by industrial and urban sewage was higher than which irrigated with ground water. The researchers of this study suggest that we seriously should be avoided from entering the urban and industrial sewage to water which irrigate the agricultural products

Characteristics, distribution and sources of polychlorinated biphenyls (PCBs) in coastal sediments from the heavily industrialized area of Asalouyeh, Iran

In this research, the levels of polychlorinated biphenyls (PCBs) were investigated in the marine sediments of Asaluyeh harbor, in the Persian Gulf. The samples were taken from industrial, semi-industrial and urban regions. The mean concentration levels of total (Σ) 18 detected PCBs were 514.32, 144.67 and 31.6 pg/g dw for the industrial, semi-industrial and urban sampling stations, respectively. Based on a multivariate statistical analysis, it was found that high contamination levels of PCBs in sediments collected along the Persian Gulf were associated with releases from local industries. Total organic carbon (TOC) content was significantly and positively correlated with the concentrations of PCB congeners. World Health Organization toxic equivalents (TEQs) for PCBs ranged from 0.04 to 2.66 pg TEQ/g dry weight (dw) in the coastal sediments. The TEQ values in this study were higher than many reported worldwide in the literature for sediments. This suggests that there are high levels of contamination in the area due to industrial and other human activities

How climate change can affect cholera incidence and prevalence? A systematic review

Although the number of cholera infection decreased universally, climate change can potentially affect both incidence and prevalence rates of disease in endemic regions. There is considerable consistent evidence, explaining the associations between cholera and climatic variables. However, it is essentially required to compare and interpret these relationships globally. The aim of the present study was to carry out a systematic review in order to identify and appraise the literature concerning the relationship between nonanthropogenic climatic variabilities such as extreme weather- and ocean-related variables and cholera infection rates. The systematic literature review of studies was conducted by using determined search terms via four major electronic databases (PubMed, Web of Science, Embase, and Scopus) according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach. This search focused on published articles in English-language up to December 31, 2018. A total of 43 full-text studies that met our criteria have been identified and included in our analysis. The reviewed studies demonstrated that cholera incidence is highly attributed to climatic variables, especially rainfall, temperature, sea surface temperature (SST) and El Niño Southern Oscillation (ENSO). The association between cholera incidence and climatic variables has been investigated by a variety of data analysis methodologies, most commonly time series analysis, generalized linear model (GLM), regression analysis, and spatial/GIS. The results of this study assist the policy-makers who provide the efforts for planning and prevention actions in the face of changing global climatic variables.</p

Levels and health risk assessments of particulate matters (PM 2.5 and PM 10 ) in indoor/outdoor air of waterpipe cafés in Tehran, Iran

To determine the concentration of particulate matters (PM 2.5 and PM 10 ), 36 samples were collected from indoor/outdoor air of hookah cafés (HS), cigarette cafés (CS), both hookah and cigarette (HCS), and no-smoking building (NS) in Tehran City from December 2017 to March 2018. The mean ± SD of PM 10 concentration in the indoor air of the cafés in terms of HS, CS, HCS, and NS sites has been 702.35, 220.20, 1156.60, and 60.12 μg/m 3 , while for PM 2.5 , the values have been 271.92, 111.80, 619.10, and 22.25 μg/m 3 , respectively. It was also found that the PM concentration inside the cafés was higher during weekend session (with a higher number of active smokers), than during the weekday sessions. Moreover, the PM levels in the indoor air of the cafés were considerably higher than those of the outdoors (p < 0.05). Based on path analysis, the number of “active smokers” had the highest influence on production of PM inside the cafés, followed by the tobacco type. Finally, the mean excess lifetime cancer risk (ELCR) for PM 2.5 in the indoor air of cafés was observed in the range of 0.64 × 10 −5 –14.98 × 10 −5 . Also, the mean of hazard quotient (HQ) for PM2.5 and PM 10 was calculated in range of 0.82–18.4 and 0.16–3.28, respectively, which corresponds to an unacceptably high risk for human health. The PM levels in the indoor air of smoking cafés in Tehran are significantly high, such that it can cause serious risks for the health of both the customers and personnel. Thus, it is necessary that suitable controlling strategies be adopted for this public health threa

Monitoring and eco-toxicity effect of paraben-based pollutants in sediments/seawater, north of the Persian Gulf

The current work is documented as the first record of the characteristics, removal efficiency, partitioning behavior, fate, and eco-toxicological effects of paraben congeners in a municipal wastewater treatment plant (WWTP, stabilization ponds) and hospital WWTPs (septic tank and activated sludge), as well as seawater-sediments collected from runoff estuarine stations (RES) and coastal stations (CS) of the north of the Persian Gulf. The median values of Σparabens at the raw wastewater and effluent of the studied WWTPs were 1884 ng/L and 468 ng/L, respectively. The activated sludge system had a greater removal efficiency (56.10%) in removing ∑parabens than the septic tank (45.05%) and stabilization pond (35.54%). The discharge rates of methyl paraben (MeP) was computed to be 2.23, 21.18, and 9.12 g/d/1000 people for stabilization ponds, septic tank, and activated sludge, respectively. Median concentrations of Σparabens in seawater (103.42 ng/L) and sediments (322.05 ng/g dw) from RES stations were significantly larger than from CS stations (61.2 and 262.0 ng/g dw in seawater and sediments, respectively) (P < 0.05). The median of field-based koc for Σparabens was 130.81 cm3/g in RES stations and 189.51 cm3/g in CS stations. It was observed that the concentration of parabens could have negative impacts on some living aquatic populations (invertebrates and bacteria), but the risk was not significant for fishes and algae