Avicenna Journal of Environmental Health Engineering
Volume:8 Issue: 1, Jun 2021

The objective of this study was to investigate the removal of lead from aqueous solutions using Lignin-containing cellulose (LCNF) as natural adsorbent and advanced material in the batch system. The water sources contaminated with heavy metals, such as lead, have now become one of the major issues in the world due to non-degradability and huge adverse effects on the health of living organisms. X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) were used to analyze the physical, chemical, and structural properties of LCNFs. The parameters measured in the batch system included pH (4-9), adsorbent dosage (0.1-1 g), contact time (15-120 minutes), initial lead concentration (10-50 mg/L), and temperature (15-40°C). The data for each treatment were statistically studied by analysis of variance (ANOVA) and Duncan’s test. Based on the results, the optimal parameters were determined to be initial lead concentration of 10 mg/L, pH of 6, and adsorbent dosage of 0.3 g/L. The highest lead removal efficiency was achieved at 25°C. The system reached equilibrium at 60 minutes, and then there was little change in lead removal. The results of this study showed that LCNF, by removing more than 99% of lead from aqueous solutions, is a suitable adsorbent for removing lead from aqueous solutions.

Pollution of water resources with pesticides is one of the environmental problems and a serious threat to the communities’ health. This study aimed to determine the residual concentration of pesticides in urban drinking water networks of Hamadan province in 2019. In order for investigating the residual concentration of organochlorine (aldrin, dieldrin, lindane, methoxychlor and permethrin), organophosphorus (chlorpyrifos, diazinon and malathion), and carbamate (atrazine and alachlor) pesticides in urban drinking water distribution networks of the province, a total of 46 samples were taken. The samples were analyzed by GC-ECD and the results were analyzed using Excel software (a descriptive cross-sectional study). The residues of aldrin, dieldrin, lindane, diazinon, malathion, atrazine, and alachlor were found in none of the samples. The maximum concentrations of chlorpyrifos and permethrin were 2.20 and 8.03 μg/L, respectively. The methoxychlor residue was observed only in one sample (C=0.35 μg/L) and all other samples were free of methoxychlor. Residues of studied pesticides in all samples are much less than the maximum allowable in the national standard and the World Health Organization (WHO) and Environmental Protection Agency (EPA) guidelines. Therefore, it can be concluded that the studied networks water quality as well as the urban drinking water resources in Hamadan province are at a very desirable level in terms of the pesticide residues. If the consumption of pesticides is not controlled, there is a possibility of increasing the concentration of these pollutants in water resources, which in turn may threaten the human health in the future.

Mycotoxins are known to be one of the most important food contaminants that pose potential health risks to humans. This study aimed to investigate the changes in total aflatoxin (TAF) content during grape vinegar production. Different types of aflatoxins including aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), and G2 (AFG2) were spiked into washed grape samples in the level of 5 μg/kg. Then grape samples were converted to vinegar. After different stages of vinegar processing including juicing, alcoholic fermentation, acetic acid fermentation, and pasteurization, sampling was performed and the level of each aflatoxin was measured using high performance liquid chromatography with fluorescence detector (HPLC-FD). Among different processing steps, the pasteurization operation had the least effect on the removal of aflatoxin. After juicing, the amount of AFB1, AFB2, AFG1 and AFG2 decreased by 14%, 11.18%, 13.77%, and 18.56%, respectively. Alcoholic fermentation had the greatest effect on the removal of aflatoxin so that it could reduce the levels of AFB1, AFB2, AFG1 and AFG2 by 41.87%, 45.34%, 45.37%, and 46.52%, respectively. Overall, during processing and conversion of grapes to vinegar, the values of AFB1, AFB2, AFG1 and AFG2 were reduced by 76.20%, 71.06%, 69.26%, and 75.85%, respectively. Processing grapes to vinegar can have a significant effect on the aflatoxin reduction.

The aim of this study was to determine the toxicity of cefixime in the inlet solution and effluent treated with the sono-electro-Fenton process using standard strains of microorganisms. This research was performed as an experimental study, which was conducted on a laboratory scale. The standard strains of Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) were used for bioassay. First, the stock solution of 1000 mg/L containing Cefixime was prepared, and for each bacterium (gram-positive and gram-negative), 5 samples from the inlet solution of the reactor and 5 samples from effluent treated with the sono-electro-Fenton process were collected under optimal conditions. Finally, each sample was transferred to 10 mL of sterile lactose broth, and a loop of E. coli or S. aureus was dissolved in each sample. Toxicity changes were investigated by calculating the percentage of growth inhibition. The results showed that after 10 hours, the growth rate of both bacteria in the control and the effluent samples was higher, while the growth of bacteria in the inlet solution was lower and had higher toxicity. Based on the results of the study, the toxicity rate for E. coli was reduced from 70% in the inlet solution to 9.3% in the effluent (86.7% reduction in toxicity), and in the case of S. aureus, it was diminished from 25.3% in the inlet solution to 7% in the effluent (72.3% reduction in toxicity) after 10 hours. Based on the results of the present study, bioassay using microorganisms is an effective and useful method to study changes in the toxicity of cefixime.

The hygiene hypothesis links the environmental and microbial exposure in early life to the prevalence of atopy, allergy, and asthma. Helicobacter pylori infection is typically acquired in childhood and the acquisition is associated with poor household hygiene. In this study, the current knowledge on the activity of essential oils and extract of Apium graveolens L. (celery seeds) and their derivatives against H. pylori was reviewed. Celery seeds were prepared at the Pharmaceutical Farm (Babol, Mazandaran) of Iran. The essential oils were extracted by a Clevenger approach and analyzed using GC-MS, and maceration method was used to prepare the extract. H. pylori bacteria were isolated by the cultivation of gastric biopsy removed from the patient who had gastric ulcer. The antibacterial activities of both essential oils and extract against H. pylori were evaluated by agar dilution method, and the corresponding MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values were determined for each sample. The results showed that the main components in celery seed essential oils were α-pinene (20.25%), β-pinene (16.62%), and Sabinene (7.81%). Among different samples, essential oils of celery seed exhibited better effect on H. pylori with MIC value of 1.56 mg/mL and MBC value of 3.12 mg/mL. Methanol and water extracts of celery seed showed MIC values of 0.38 mg/mL and 0.78 mg/mL and MBC values of 1.56 mg/mL and 6.25 mg/mL, respectively (P≤0.005). The results of this study indicated that all the samples had antibacterial effect against H. pylori due to antibacterial components.

This descriptive, cross-sectional study aimed to assess the correlations between the knowledge, attitude, and performance of the students of Hamadan University of Medical Sciences, Iran, regarding waste recycling in 2020-2021. A questionnaire was used for data collection, and the sample population consisted of 70 male and female students. Data were analyzed using SPSS version 21 by Mann-Whitney and Kruskal-Wallis (α=0.05). The sample population included 87.1% women and 12.9% men. In total, 22.9% of students received special training to recognize the adverse effects and management of waste while 77.1% of them received no training. In addition, 22.9% of students reported the contraction of infectious diseases in themselves or others around them due to contact with garbage or contaminated equipment. The marital status had a significant difference with the amount of knowledge of the studied students for determining the type of awareness regarding the importance of recycle waste while gender represented no substantial difference in this regard. Based on the results, a positive correlation was observed between attitude and awareness, as well as the performance with knowledge and attitude. Knowledge, attitude, and performance are meaningful predictors of waste management. According to the results, the importance of waste management should be emphasized to student in the community in terms of the current health conditions. It also seems that the influential factors in waste management should be fully identified in interventional programs, and appropriate interventions should be planned and implemented accordingly.

The current study was undertaken to determine the concentration of lead, cadmium copper, and zinc (Pb, Cd, Cu, and Zn) in three types of collected green leafy vegetables irrigated with contaminated water compared with those irrigated with the fresh water of Hamadan province, Iran using the inductively coupled plasma mass spectroscopy (ICP-MS) technique. Twenty samples of vegetables such as basil, leek, and lettuce irrigated with contaminated water, and twenty samples from five different adjacent areas irrigated with fresh water as control were analyzed to determine heavy metals (HMs). The highest mean concentration of Pb, Cd, Cu, and Zn, regardless of the kind of vegetables irrigated with contaminated water, was 0.95, 0.32, 3.03, and 13.58 mg/kg fresh weight, respectively. Moreover, metals uptake differences by the vegetables were recognized to vegetable differences in tolerance to HMs. The human health risk assessment indicated that non-carcinogenic values of Pb and Cd were higher than the threshold value of 1, and ingestion was the main exposure pathway of HMs to both children and adults. It suggested that all receptors (especially basil and lettuce) in Hamadan province might have significant and acceptable non-carcinogenic risk because of exposure to Pb and Cd. The significant amount of these HMs in some plants may be due to agricultural uses for the irrigation of the vegetable lands of untreated sanitary and industrial wastewater. The findings revealed that vegetables imply the total health risk on local people, and regular monitoring of HMs is strongly recommended in this region.

A surface area of 1085.92 m2/g and a monolayer adsorption capacity of 497.66 mg/g were obtained from the optimum activated carbon derived using Prosopis africana seed hulls (PASH-AC) at the activation temperature of 795°C, activation time of 62 minutes, and impregnation ratio of 2.45. Five different forms of the linearized Langmuir equations along with two other models (Freundlich and Temkin) were tested on the adsorption data. The best adsorption model was selected using correlation coefficient (R2) and chi-square (χ2) was used for assessing the validity of each isotherm model. Langmuir-2 along and pseudo-second-order models were found to be the most suitable model for describing the equilibrium and kinetic processes, respectively.