فهرست مطالب
Environmental Health Engineering and Management Journal
Volume:8 Issue: 3, Summer 2021
- تاریخ انتشار: 1400/05/10
- تعداد عناوین: 9
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Pages 153-167Background
Biological soil crusts (BSCs) that are able to produce sticky extracellular polymeric substances (EPS) play an important role in the formation of soil aggregates, thereby, reducing soil erosion. In this study, experiments were undertaken to identify biocrust species that produce EPS, in
order to combat desertification in the Sejzi desert of Iran.MethodsA biocrust distribution map of Sejzi plain was prepared using Landsat 8 OLI images, then, various sampling points were selected. Some physicochemical parameters of samples from lichendominated and non-biocrusted areas were measured. The relationship between soil parameters and biocrusts presence was confirmed based on the Pearson’s correlation coefficient and principal component analysis (PCA) method. The type of chemical compounds in the soil content were determined via Fourier transform infrared spectroscopy (FTIR), including polysaccharides. To estimate the degradability of polysaccharides, each soil sample was placed under defined UV-B radiation for 24, 48, and 72 hours at three replications.
ResultsThere was no significant correlation between moss and lichen species with the amount of EPS (%) values and various occurring cyanolichen species in three biocrusted soil samples, which included Collema coccophorum, Collema tenax, Peccania terricola, and Placidium squamulosum. It was speculated that these polysaccharides were produced by the photobiotic partners (microalgae or cyanobacteria) and secreted to the soil.
ConclusionAccording to the results, the cyanobacteria species of biocrusted samples might have high potential to combat desertification and soil stabilization in Sejzi desert.
Keywords: Cyanobacteria, Fourier transform infrared, Lichens, Polysaccharides, Sejzi plain, Iran -
Pages 169-178BackgroundFloods are the most common natural disaster which may have substantial impacts on the human health and life and the environment. In recent years, Iran have faced many floods and it seems that increasing impacts of floods in Iran are attributed to inadequate preparation and no well-established strategies and guidelines for response by health sector and other related response organizations. So, this study was conducted to review the current plans in the world to identify the required elements of the flood emergency response plan to prevent its consequences on the health sector in Iran.MethodsA comprehensive review was performed through search on electronic data bases, including, Medline, Scopus, ProQuest, and e-journals which were accessible during 2010-2020. The keywords were response plan, flood, requirements, guidelines, and health sector. Data were collected using data extraction form and analyzed through content analysis.ResultsIn the initial search, 960 possible sources of flood response were identified. After excluding duplicate papers and the documents that did not contribute to the flood response plan, 64 articles and programs or guidelines that all them has been reviewed, were obtained. The findings were divided into two groups, response prerequisites and response activities.ConclusionThis review provided a complete view of the flood consequences for the health sector and allows professionals to incorporate facets of the health effect of floods into a flood response plan. The flood response plan was divided into two general categories: Initial and specific, each of which plays an important role in preventing the negative effects of the floods.Keywords: Flood, Response plan, Health sector, Response prerequisite, Response action
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Pages 179-185Background
One of the biggest global occupational threats, especially in the outdoor workplace, is climate change and global warming, as workers are exposed to the heat stress leading to reduced performance. The aim of this study was to investigate the effect of workplace climate on labor productivity index in the agricultural sector.
MethodsIn this study, data related to environmental variables of 215 synoptic meteorological stationsin Khuzestan province were collected from three climatic regions (hot, mild, and cold). Using MATLAB R 2018b mathematical software based on ASHRAE/ISO7730 standard values by designing some scenarios, predicted mean vote (PMV) index, and then, labor productivity index (P) were estimated. The data were analyzed using SPSS version 25 software.
ResultsThe results showed that in the hot regions, there is a significant inverse relationship between P index and the main environmental variables (ta, tr, pa). In the cold regions, increasing the amount of ta and tr in light and medium workload improved the P index, but for heavy workload, it reduced productivity, and the most effective factor was increasing air vapor pressure. In the mild regions, the most effective factor in productivity was air vapor pressure. In addition, the results of Spearman’s correlation coefficient showed that PMV index has a direct and significant relationship with P index.
ConclusionRegarding the increasing trend of climate change and its effect on the desired thermal comfort and productivity, well structure and planning is needed to manage farm workers health.
Keywords: Workplace, Climate conditions, Labor, Agricultural -
Pages 187-195Background
Exposure of children and adolescents to endocrine disrupting chemicals (EDCs) causes the development of non-communicable diseases. Triclosan (TCS) is a fat-soluble antimicrobial agent, and methyl-triclosan (MTCS) is the predominant metabolite of TCS. The increasing use of consumables TCS (toothpaste, mouthwash, personal care products) in human has raised concerns about human health.
MethodsThe urinary concentrations of TCS and MTCS were measured by GC/MS. Lipid profiles (TG, TC, LDL, and HDL), anthropometric parameters (WC, BMI z-score, and BMI), FBS, SBP, and DBP tests were performed on 79 children and adolescents.
ResultsOf 79 people included as the study population, 42 subjects (53.16%) were males. Most of the study population as 32 subjects (40.50%) were obese. The mean concentrations of TCS and MTCS in the obese population were 5.47 ± 2.99 and 2.32 ± 1.04 µg/L, respectively. After adjusting for possible confounding factors, the results showed that a one-unit increase in DBP caused a 0.03 units increase in TCS levels in male subjects (P = 0.01). A one-unit increase in DBP also caused a 0.02 units increase in MTCS (P = 0.001). There was a significant relationship between TCS and HDL (OR = 0.90, P = 0.005), LDL (OR = 1.13, P = 0.01), and TG (OR =1.05, P < 0.0001). There was also a significant relationship between MTCS and HDL (OR = 0.88, P = 0.001), LDL (OR = 1.03, P = 0.009), and TG (OR = 1.04, P < 0.0001).
ConclusionAccording to the results, there is a relationship between TCS, MTCS, and predictive indicators of cardiovascular diseases and obesity.
Keywords: Triclosan, Methyl triclosan, Cardiovascular disease, Obesity, Endocrine disrupter, Children, Adolescent -
Pages 197-204Background
After suffering from an acute problem of excess water for a long time, the Oasis of Ouargla benefited from an aerated lagoon treatment plant, producing biologically treated domestic effluents. The aim of this study was to examine the feasibility of reusing this effluent for watering plants. The experiment was conducted in the Ouargla WWTP, which is located in the region of Said Otba (northeast of Ouargla), north of the national road NR 49.
MethodsThe study area was selected based on the originality of the study and availability of water. The plants used were Acacia farnesiana and Leucaena leucocephala. The selection of Leucaena was based on the following criteria: It is used as a windbreak, it is very tolerant to drought, and it is used as a fodder to maintain soil fertility. And, Acacia was selected because it is used as a fodder, protects the soil against erosion, and to fix nitrogen. The watering of these plants is done jointly by treated wastewater from the WWTP and well water (WW), of which the latter was used as a control. Sampling and analysis of the irrigation water were performed according to the experimental protocol. To show the growth rate of the two plants studied, biometric measurements were taken weekly for 25 weeks.
ResultsThe physicochemical analyses show that the treated wastewater is of poor quality belonging to the last class of Riverside’s C5-S4, with an excessive salinity (EC) of 13.51 dS/m and an Sodium adsorption ratio (SAR) of 12.61 against EC of 2.49 dS/m and 2.13 for the WW. At the end of the experiment, it was found that irrigation with purified wastewater (PWW) gave less growth compared to that with WW. Statistical analyses of the biometric measurements confirmed that there is a highly significant difference at P < 0.05.
ConclusionThe reuse of WWTP effluent gives less interesting results but is still possible. It is recommended to choose Salt-tolerant crops, as well as the dilution of these waters by the addition of less salty waters.
Keywords: Well water, Treated waste water, Forest species, Irrigation Saharan area, Wastewater reuse -
Pages 205-214BackgroundThe present study aimed to assess the acute impact of erythromycin (ERY) as an inhibitor on peptone mixture utilization of activated sludge (AS) consortium.MethodsFor this purpose, the inhibition of oxygen consumption was used based on the ISO 8192:2007 procedure. In this method, the AS consortium (10-day age) was extracted from labscale membrane bioreactor, then, percentage inhibition for total, heterotrophic, and nitrifying microorganisms, in separate batch respirometric tests were calculated in the absence and presence of N-allylthiourea (ATU) as a specifc Nitrifcation inhibitor.ResultsThe obtained data showed that the height of oxygen uptake rate (OUR) profles and amount of oxygen consumption reduced with increasing ERY dose. The half-maximal effective concentration (EC 50) of ERY for heterotrophic and nitrifer microorganisms were 269.4 and 1243.1 mg/L, respectively. In Run 1, the kinetic coeffcients bH, fA,H, YH, and µH were calculated as 2.61 d-1, 0.44, 0.4945 mg VSS/mg COD, and 0.047 d-1, respectively. Also, for maximum ERY concentration (1000 mg/L), the kinetic coeffcients bH., fA,H, YH, and µH were calculated as 2.27 d-1, 0.3, 0.4983 mg VSS/mg COD, and 0.0049 d-1, respectively.ConclusionThe fndings showed that the inhibitory impact of ERY was observed as a decrease in the amount of oxygen consumption by OUR profles in rapid respirometric method (ISO 8192), which offered a novel insight for the acute inhibitory impact of this antibiotic. Also, chemical oxygen demand (COD) as an overall substrate parameter is most helpful in interpreting the behavior and the metabolic functions of AS systems.Keywords: Toxicity, Erythromycin, Activated sludge, Respirometry, Kinetic coeffcients
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Pages 215-226Background
PIn air quality studies, it is very often to have missing data due to reasons such as machine failure or human error. The approach used in dealing with such missing data can affect the results of the analysis. The main aim of this study was to review the types of missing mechanism, imputation methods, application of some of them in imputation of missing of PM10 and O3 in Tabriz, and compare their efficiency.
MethodsMethods of mean, EM algorithm, regression, classification and regression tree, predictive mean matching (PMM), interpolation, moving average, and K-nearest neighbor (KNN) were used. PMM was investigated by considering the spatial and temporal dependencies in the model. Missing data were randomly simulated with 10, 20, and 30% missing values. The efficiency of methods was compared using coefficient of determination (R2), mean absolute error (MAE) and root mean square error (RMSE).
ResultsBased on the results for all indicators, interpolation, moving average, and KNN had the best performance, respectively. PMM did not perform well with and without spatio-temporal information.
ConclusionGiven that the nature of pollution data always depends on next and previous information, methods that their computational nature is based on before and after information indicated better performance than others, so in the case of pollutant data, it is recommended to use these methods.
Keywords: Air pollution, Algorithms, Environmental pollutants, Spatio-temporal analysis, Humans -
Pages 227-235Background
Chemical stabilization of heavy metals in acidic soil is one of the important points in environmental pollution. Thus, this research was conducted to investigate the effect of organic and inorganic amendments on lead (Pb) immobilization in the Pb-polluted soil.
MethodsTreatments were consisted of applying cow manure (0, 15, and 30 t/ha), and applying cow bone and phosphate rock (5% (W/W)) in the Pb (0, 800, and 1600 mg Pb/kg soil)-polluted soil. The plant used in this experiment was canola. After 70 days, the plants were harvested and soil and plant Pb concentration was measured using atomic absorption spectroscopy (AAS).
ResultsApplying 15 and 30 t/ha of cow manure in the Pb (1600 mg Pb/kg soil)-polluted soil significantly decreased the soil Pb concentration by 14.3 and 17.2%, respectively. For plant Pb concentration, it was increased by 11.8 and 15.1%, respectively. A significant decrease in plant Pb concentration was measured, when the soil under cultivation of the plant was amended with 5% (W/W) phosphate rock powder. For the plants grown on the soil, which was amended with 5% (W/W), the plant Pb concentration decreased by 17.6%. In addition, applying organic and inorganic amendment significantly decreased the bio-concentration factor (BCF), while the soil microbial respiration increased.
ConclusionThe results of this study showed that applying 15 and 30 t/ha cow manure or calcium and phosphorus sources such as cow bone and phosphate rock powder (5% (W/W) can decrease the soil Pb availability and prevent the Pb translocation from soil to plants.
Keywords: Environmental pollution, Soil, Lead, Soil microbiology -
Pages 237-244Background
Leachate contains toxic and non-biodegradable substances that are not easily treated by conventional treatment methods. This study investigated the effect of pH, current density, and reaction time parameters on the removal of cyanide (CN-), nitrate (NO3-), turbidity, and chemical oxygen
demand (COD) from leachate by electrocoagulation process.MethodsThis study was an experimental one with direct current using four parallel bipolar aluminum electrodes with 90% purity. The length, width, and thickness of the electrodes were 5 cm, 10 cm, and 2 mm, respectively. There were 6 holes with a diameter of 0.7 cm on each of the electrodes. The samples were prepared from the old leachate of solid waste landfill in Ghaemshahr, Iran.
ResultsIn this study, at a current density of 33 mA/cm2 and a time of 60 minutes, the optimum removal efficiency of cyanide (100 %) was obtained at pH 5.5 and pH 10. Moreover, the maximum removal of nitrate (99.65 %) and turbidity (86.41 %) were at pH 5.5 and pH 8.3, respectively and the highest removal efficiency of COD (83.14 %) was obtained at pH 10.
ConclusionThe results showed that the removal of cyanide, nitrate, turbidity, and COD increases with increasing current density and reaction time. Due to the proper removal of nitrate and cyanide from leachate by electrocoagulation, nitrate and cyanide amounts were less than the allowable contamination level. Based on the results, electrocoagulation is considered an efficient and effective method for removing nitrate and cyanide from old leachate of municipal solid wastes.
Keywords: Electrocoagulation, Cyanides, Nitrates, Chemical oxygen demand analysis, Solid waste