Environmental Health Engineering and Management Journal
Volume:9 Issue: 2, Spring 2022

To mitigate the climate change, several researches have been conducted to determine the determinant factors of CO2 emissions. Nonetheless, a consensus was failed to reach yet on the issue because many of the previous studies did not deliberate the undetected individual heterogeneity across countries. The study aimed to investigate the effects of economic growth, foreign direct investment and financial development within the research background of seven leading African economies over the 49- year period from 1970 to 2019.

In this study, the determinant factors of environmental quality were examined by employing a panel quantile regression. The advantage of the method is considering the distributional heterogeneity to provide a detailed description regarding the driving factors of carbon emissions.

It was revealed that the effects of determinants on CO2 emissions are heterogeneous. The quantile regression estimate describes that the influence of economic growth on CO2 emissions is positive and higher at the 50th quantile than in other classes of quantile. The effect of financial development on CO2 emissions is higher and positive at the 90th quantile compared to other categories of quantile. The FDI influence on CO2 emissions is heterogeneous across different quantiles and the coefficient is significant and larger at the 10th quantile than in all the other quantiles.

In addition, the study recommends that environmental policies that minimize emissions should be enforced for the purpose of making the environment cleaner, FDI should be environmentally friendly, and relevant incentives are required to redirect private credits towards green projects and renewable energy development.

Polycyclic aromatic hydrocarbons (PAHs) have detrimental effects on human, ecosystem, and biodiversity. Bioremediation is an option that has been used to remediate and reduce the risk of contaminants such as PAHs. Microorganisms are readily available to screen and can be rapidly identified to be used in many extreme environmental conditions. Mycobacteria have a great potential for the production of bioactive compound, which have degradation activity. Due to this issue, and also, as there is no study conducted on the biodiversity of biodegradable Mycobacterium in Markazi province, the present study aimed to assess the isolation and identification of biodegradable Mycobacterium species from diverse Markazi province ecosystems.

Mycobacterium were screened from a total of 30 soil, water, and sludge samples from the oilpolluted ecosystems of Markazi province and characterized to the genus and species level by applying molecular and conventional microbiological assay including the PCR amplification and sequence
analysis of 16SrRNA and hsp65 genes. The growth rate in the presence of PAHs, turbidometry, and high performance liquid chromatography (HPLC) were used to determine their bioremediation capability.

In total, 6 Mycobacterium isolates (20%) were screened from 30 samples, which belonged to two species of Mycobacterium consisting of M. porcinum (4 isolates) and M. celeriflavum (2 isolates). The strains of M. porcinum and M. celeriflavum could degrade 70% and 90% of 1 mg/L PAH solution in 7 days.

According to the results, the M. porcinum and M. celeriflavum have a significant capability to biodegrade the PAHs. Therefore, more investigations are recommended for separation and applicational use of the mycobacterium species for bioremediation of PAHs.

The contamination of soil and water with hydrocarbonic pollutants is a major environmental problem. Soil water repellency will interrupt water infiltration, and may decline plant growth and potentially trigger soil erosion. The aim of this study was to investigate the effect of soil and water contamination by oil on soil water repellency, where the soil has been oil-contaminated due to mismanagement of the lands surrounding the refineries, and many of the trees in the area have dried up.

Water drop penetration time test (WDPT) was performed on contaminated soils. To investigate the effect of the surface water contamination on soil, handmade soil samples were collected and successive dry/wet cycles were applied to them by contaminated and non-contaminated waters. Subsequently, soil water repellency tests, including molarity of ethanol droplet (MED), water and ethanol sorptivity were performed on soil samples. The soils were passed through a 2 mm sieve after being air-dried and the soil texture was determined by pipette method. The SWR was measured by WDPT in the area contaminated with petroleum compounds and 7 to 10 replicates were assigned to each location. In order to determine the effect of water contamination on the area soil and to measure water repellency in the laboratory, disturbed soil samples (36 samples) with a bulk density equal to 80% of the reference bulk density were prepared.

The results showed that soil oil-contamination causes water repellency, increased WDPT, a significant increase in water repellency index, and a significant decrease in cosθ at the level of 0.001. The effect of water contamination on the indices and cosθ were statistically significant at the 0.001 and 1% levels, respectively. Therefore, contaminated water increased the water repellency of the soil after successive dry/wet cycles.

Significant positive correlations between organic and water repellency indices and significant negative correlations between cosθ and organic indices indicate the effect of oil-contamination of water and soil on creating and increasing the intensity of soil water repellency.

Olive mill wastewater (OMW) is characterized by its high organic content and refractory compounds. The aim of this study was to evaluate and compare the efficiency of UV/O3 and UV/ acetylacetone (UV/AcAc) processes for treatment of pretreated OMW by coagulation/microfiltration (C&M) process.

In this study, a laboratory-scale UV plug flow reactor with ancillary equipment was fabricated. The experimental factors including initial pH (5-9), O3 dosages (1.5-4.5 g/h), and AcAc concentrations (0.01-0.03 M) were measured. For both processes, a reaction time of 120 min was considered. The effect of these variables on removal of wastewater contaminants including BOD, COD, TSS, turbidity, phenol, oil, and grease were investigated.

Results showed that raw OMW has a high load of pollutants and very low biodegradability (BOD5/COD = 0.12). In UV/O3 process, the optimal conditions were obtained at pH 8 and ozone injection at 4 g/h. The combined C&M-UV/O3 process removed 78.75% COD, 46.66% BOD5, 90.88% total phenol, 91.78% TSS, 99.14% oil and grease, and 98.38% turbidity, with promotion of BOD5/ COD from 0.12 to 0.33. In UV/AcAc process, the optimal conditions were achieved at pH 5 and AcAc concentration of 0.03 M. The combined C&M-UV/AcAc process removed 58.75% COD, 67.58% BOD5, 38.03% total phenol, 83.50% TSS, 93.65% oil and grease, and 95.00% turbidity, with promotion of BOD5/ COD from 0.12 to 0.22.

The results showed that the UV/O3 process is completely superior to the UV/AcAc process for removal of OMW contaminants, as well as promoting the biodegradability of OMW.

Reservoirs serve as fishing and domestic water resources for the people living around the catchment area. However, natural activities threaten the water quality, therefore, constant and proper monitoring of the reservoir is necessary. This study aimed to examine seasonal variation in water quality parameters of Kubanni reservoir, Zaria, Nigeria.

Water quality data of Kubanni reservoir, Zaria, Nigeria, for 7 years (January 2014 to December 2020) were collected and analyzed to understand the seasonal variation. Ten water quality parameters including pH, turbidity, electrical conductivity (EC), temperature, total dissolved solids (TDS), dissolved oxygen (DO), chloride (Cl-), total Iron, nitrate (NO3-), and manganese (Mn) were analyzed. The data were analyzed using Kolmogorov-Smirnov test to select the probability distribution which provides the best fit by EasyFit software. The functions included Weibull, Exponential, Fréchet, Gamma, Lognormal, and Normal. Seasonal variation was determined using Spearman’s rank-order correlation.

The results showed that pH, EC, temperature, TDS and NO3- approach the Weibull distribution. Turbidity and total Iron approach the Fréchet distribution. Mn approaches the normal distribution, while DO and Cl- approach the Gamma distribution. The output of non-parametric Spearman’s correlation coefficient and Spearman’s statistical criterion indicates a significant difference at 5% significance level between the pH and total Iron values recorded in both seasons. This suggests that season has an effect on the concentration of pH and total Iron.

Out of the 10 parameters examined, pH and total Iron are climatologically influenced.

One of the key indicators of the degradation of the environment is the noise level. This has necessitated this study on the evaluation of the public, perceptional awareness, sources, effects, and mitigation measures on environmental noise pollution.

The population was estimated and 385 structured questionnaires were estimated and administered by random purposive sampling. About 358 questionnaires were retrieved. Data were analyzed using SPSS and Excel statistical software.

About 90.2% of the respondents had relevant awareness and its effects on environmental noise while 9.8% of the respondent did not. Traffic, generators, commercial and light industry sources of noise, and their severity were ranked in a descending order using the Likert scale. Hearing impairment, annoyance, stress, distraction during exposure were ranked in a descending order using the Likert scale. Single-factor ANOVA on the sources of noise and their severity, awareness of the various effects of noise, and responses during exposure showed that there were significant differences as P<0.05 using a confidence level of 95%. About 61.7% of respondents complained of environmental noise, 72.6% respondents received complaints about environmental noise, 87.7% of respondents were not aware of any government agency monitoring noise pollution, 72.2% of the respondents had done nothing regarding noise prevention, and 91.1% respondents wanted a proactive decision in mitigating environmental noise pollution.

There is an inadequate coping strategy. Strategic planning in mitigating environmental noise in urban and semi-urban areas is a necessity and there is a need for public enlightenment by government monitoring agencies.

Pharmaceuticals and personal care products (PPCPs) are a group of emerging environmental pollutants that have attracted the attention of many researchers due to their harmful effects on aquatic environment, animals, and humans. Thus, it is necessary to remove these contaminants from water resources. This study aimed to assess the efficiency of enhanced electro-Fenton (EF) process by persulfate (PS) radical for removal of atenolol (ATL) from aqueous solutions.

The bench scale experimental setup was used to examine the factors affecting the ATL removal efficiency from synthetic wastewater; supporting electrolyte type, pH, contact time, PS concentration, Fe concentration, and ATL initial concentration.

Based on the results, ATL removal efficiency of 78.6% was reached under the optimum conditions of enhanced EF process by PS radical. The optimum conditions included NaCl (as a supporting electrolyte) dose of 0.5 g/L, pH 5, contact time of 60 minutes, PS dose of 0.15 g/L, Fe dose of 0.15 g/L, current density (CD) of 1.5 A/m2, and ATL concentration of 40 mg/L. Kinetic model was following the second-order kinetics.

The studied advanced oxidation process (AOP) can effectively remove ATL from aqueous solutions. Therefore, it can be used as an effective technique for removing other organic matter from the wastewater.

Heavy metals are considered as pollutants polluting aquatic ecosystems because of their toxic effects and bioaccumulation in organisms. They can cause chronic poisoning when ingested by human. The present study was conducted to determine the concentration of heavy metals, mercury (Hg), lead (Pb), cadmium (Cd), and chromium (Cr) in the muscle tissue of Liza abu and Brachirus orientalis fish in Mahshahr, and also, to estimate the risk of muscle consumption of these fish.

Forty samples of both fish species were randomly selected and after preparation and extraction and digestion processes, the metals were measured using ICP-OES Agilent Model 5100.

The mean concentrations of Hg, Pb, Cd, and Cr in the muscle tissue of the Liza abu fish were 0.616 ± 0.383, 1.227 ± 1.77, 0.076 ± 0.030, and 0.567 ± 0.267 mg/kg dry weight, and in the muscle tissue of the Brachirus orientalis fish were 0.846 ± 0.659, 0.515 ± 1.245, 0.061 ± 0.047, and 0.586 ± 0.548 mg/kg dry weight, respectively. HI for Liza abu and Brachirus orientalis was 0.025 and 0.336, respectively.

According to the results of this study, the concentrations of Hg and Cr in the muscle tissue of Liza abu and Brachirus orientalis were slightly higher than some global standards such as the World Health Organization (WHO) and Food and Agriculture Organization (FAO). HQ index was below 1 for two fish species, meaning that there was no non-carcinogenic risk. In all samples analyzed, carcinogenic risk Cr was slightly above the permissible limit of 1×10-4 to 1×10-6 ،other metals were in this range.

The aim of this research was to assess the Humidex (HD) trends as a thermal discomfort index by analyzing meteorological data during a 30 year period of summertime in Iran.

For this purpose, data regarding average temperature and relative humidity were collected daily from 40 different synoptic meteorological stations during a 30-year statistical period (1985-2014). The HD index was calculated based on temperature and relative humidity according to an equation introduced by Masterton and Richardson. The Mann-Kendall and Sen’s slope tests were performed to analyze the changing trend of the HD.

Based on the findings, in 72% of the meteorological stations, the HD followed an upward trend, so that 40% of them was statistically significant. The changing trends in temperature during summertime throughout the studied years fluctuated greatly but generally, in many regions such as the arid, semi-arid, and humid regions, this trend was mostly incremental. Also, the changing trends in relative humidity in all regions was decremental throughout the years under study.

The changing trend of the HD, which is based on temperature and humidity, was incremental in arid and semi-arid regions and decremental in the Mediterranean and humid regions.

Nowadays there is a problem related to wastewater handling which is released from different activities. Electrocoagulation has been a dominant treatment method for wastewater treatment. There are different forms of electrocoagulation methods for wastewater treatment. Nevertheless, there was no comparison made for the removal efficiency of the sono-alternate current (SAC), alternate current (AC), sono-direct current (SDC), and direct current (DC) electrocoagulation process.

The efficiency of electrocoagulation method was compared for removal of color and turbidity from Jimma University domestic wastewater. Batch reactor DC/AC electrocoagulation cell was used to determine the removal efficiency. During the comparison, the response surface methodology (RSM) was used to analyze and optimize the data taken from the laboratory. In addition, ANOVA was used to analyze the interaction effects of different parameters.

The removal of color and turbidity from domestic wastewater was about 97.53% and 95.28% respectively, using direct current electrocoagulation (DCE). For alternate current electrocoagulation (ACE), the removal of color and turbidity was 98.35% and 96.12%, respectively. The removal of color and turbidity for sono-DCE (SDCE) was obtained to be 98.55% and 98.27%, respectively and for sono- ACE (SACE), the removal of color and turbidity was 99.95% and 99.76%, respectively at the optimum experimental conditions of chemical oxygen demand (COD) 960 g/L, initial wastewater pH of 6.8, the current density of 0.4 A/dm2, inter-terminal spacing of 1 cm, and the association of electrode of Al-Al.

According to the findings of this study, it can be concluded that, the SAC electrocoagulation method is the best and promising technique compared with all other electrocoagulation methods.

Intervertebral disc degeneration (IDD) is a common disability in the working-age population. The underlying pathogenesis of IDD needs elucidation. This study aimed to determine differentially expressed circular RNAs (circRNAs) in IDD by bioinformatics. Additionally, the environmental and clinical factors involved in IDD pathogenesis were reviewed.

The circRNA array profiling of patients with IDD and healthy individuals (GSE67566) was acquired from Gene Expression Omnibus (GEO). GEO2R was employed to analyze the expression profiles of the circRNAs. Functional in silico analysis was done on circRNAs with the highest differential expression. Environmental and clinical factors were reviewed through PubMed and Google Scholar.

Twenty-five circRNAs were differentially expressed in IDD. Two circRNAs (hsa_circRNA_101645 and hsa_circRNA_101852) exhibited the most downregulated and upregulated expressions. The functional in silico analysis showed that the aforementioned circRNAs harbored target
sites for AGO2 and EIF4A3 and several microRNAs. The upshots indicated that these 2 circular circRNAs might sponge hsa-miR-330-3p, hsa-miR-502-5p, hsa-miR-662, hsa-miR-874, and hsa-miR-646 and regulate PSD3, SIK2, PCYT1B, ARID5B, MTMR3, and HIPK2 expressions, which play significant roles
in autophagy and cellular senescence. Temperature, heavy metal exposure, age, overweight, occupation, exercise, hypertension, and smoking were the environmental and clinical factors associated with IDD progression.

Although the results need confirmation by experimental analysis, they reflect the possible role of particular circRNAs in IDD pathogenesis. The controversy concerning the association between IDD and environmental and clinical factors necessitates in-depth population research. Investigating novel molecular regulatory markers like circRNAs could clarify the underlying molecular mechanisms of IDD.