Journal of Advances in Environmental Health Research
Volume:9 Issue: 2, Spring 2021

This paper reviews the most available data on the possible adverse effects of mercury released from amalgam that comprises of 50 % pure mercury, 35 % silver, 12-13 % tin, 2 % copper and to up1 % zinc, indium, platinum and palladium. Despite the possible health risks of mercury from amalgam on the nervous, respiratory, renal, and endocrine systems, it is however, used in some countries, even though Sweden, Denmark, Canada, the United States and Japan have long banned the use of amalgam. Amalgam restorations are one of the main mercury-releasing sources (1800-2700 tons per year) of contamination. During chewing, grinding, brushing of teeth, breaking down of amalgam and as the temperature of the oral environment increases mercury vapor will be released. The mercury vapor enters atmosphere, wastewater in dental offices, all systemic organs, especially the lower respiratory tract, can affect the renal-urinary system or enters breast milk, fetus and finally transmits to infants. The mercury level released from amalgam in blood, urine, hair and nail of large populations of dentists, dental assistants and pregnant women is higher than the safe levels. The main neurological and psychological effects of mercury vapor include in the form of sleep disorders, amnesia, mental disorders, hair loss, memory disturbances, multiple sclerosis, Parkinson's, kidney diseases, gene-toxicity, Alzheimer, Autism, skin allergies-cancer, infertility, low-birth-weight infants and heart diseases. In order to avoid further amalgam risks to the dentists, dental assistants, pregnant women and wildlife ecosystem, it is suggested to replace the dental amalgam by composite resins.

Hazardous materials such as used batteries, containing heavy metals, find their way into the solid waste stream, which finally ended to the landfills. In this study, the amount of used batteries in Iran and their heavy metal contents was determined in the batteries entered to Tabriz landfill site. A questionnaire was applied to study the current management condition of used batteries in Tabriz and Ardabil as representative cities to the whole country. Heavy metal content of 15 AA sized batteries was determined by inductively coupled plasma (ICP). Our findings showed that 14.7% of all used batteries in the country were imported from other countries. About 76 and 24% of all batteries analyzed at the landfill site were AA-sized and cellphone batteries, respectively. In the 60% of all studied batteries, the sum of heavy metal content were less than 100 mg/kg. The findings of this study can be a useful reference for global and local policymakers in order to develop effective regulations for using cleaner materials in battery industry and control used batteries from their generation to the end of battery life.

The filtration is a processing unit in a Drinking Water Treatment Plant (DWTP) that is used to remove particles from the water. This study is the result of pilot-scale research on Gravity Rapid Sand Filter (GRSF). The purpose of this paper is to evaluate the performance of the Triple Media Filter (TMF) (Granular Activated Carbon (GAC) + anthracite + garnet) and Dual-Media Filter (DMF) (anthracite + sand) in the removal of Natural Organic Matter (NOM) as a precursor of trihalomethanes (THMs) and chlorination Disinfection by Products (DBPs). As well as filtration rate performed at conventional (120 m/d) and a high rate (240 m/d), and compared with full-sized Single Media Filter (SMF) with a sand media. The removal efficiency of Turbidity, Color, UV absorption at a wavelength of 254nm (UV254), and Dissolved Organic Carbon (DOC) parameters were investigated. Besides, the Specific Ultraviolet Absorbance (SUVA) was calculated from the ratio of UV254 to DOC. The results showed that the Multimedia Filter (MMF) at 120 and 240 m/d filtration rate had higher removal efficiency compared to a control SMF in removing measured parameters (p-value <0.05). Also, similar filters, have shown the same efficiency relative to each other in different loading rates and there was an insignificant difference. MMF can significantly remove organic pollutants and control the formation of DBPs during water treatment. The study suggests that SMF should be replaced with MMF to improve water quality.

The purpose of present study was to study absorbent ability of organic pollutants from warm water fish farms by synthesized nano-composite adsorbent. study was performed at different physicochemical condition of pH (5-8), effluent concentration (25-100 mg/L), contact time (15-90) minutes. Adsorption isotherm studies were analyzed using Freundlich, Langmuir models and adsorption kinetics studies using pseudo-first-order and pseudo-second-order kinetic models. The Langmuir and Freundlich isotherms, first and second order adsorption kinetics were investigated. The Langmuir and Freundlich isotherms for nitrite (R2 = 0.9076, R2 = 0.5911), phosphate (R2= 0.9307, R2= 0.5755) and ammonia (R2 = 0.7288 and R2 = 0.7549), respectively obtained. According to the results, the data of nitrite and phosphate pollutants were more consistent with the Langmuir model, but the data of ammonia pollutants were more consistent with the Freundlich model. According to the results, the adsorption of phosphate pollutants was more consistent with pseudo-first order kinetic model and the adsorption of nitrite and ammonia pollutants was more consistent with the pseudo-second order kinetic model.

The Caspian Sea is the largest water body in the world. It is surrounded by five states – Azerbaijan, Iran, Turkmenistan, Kazakhstan and Russia. Caspian kutum, Rutilus kutum Kamensky 1901, is a commercially important fish species in the southern part of the Caspian Sea, but little data available on trace element (TE) concentrations in its skin. In this study 51 R. kutum in the south shoreline of the Caspian Sea (including Astara, Anzali and Kiashahr) were caught during September 2017 to June 2018 and inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure TE concentrations in their skin. The trace element concentrations (TECs) measured in the skin (except for potassium) did not exhibit significant differences between the study areas. So that, only concentration of potassium was higher in Kiashahr than other areas.

In this study, the ferrous sulfate was used to remove Cr(VI) and Ni(II) ions from a real Ni-Cr plating industry wastewater. This is an applied study. The type of sampling was composite by three 5 L containers. Wastewater chemical and physical characteristics were measured in accordance with the standard methods book 14. The concentration of un-removed metal ions was estimated by ICP-OES. The Jar test type experiment was used to carry the chemical coagulation experiment. The results indicated that the rate of removal would depend on the pH estimation of 1.5-11, the diverse contact time in the range of 30-120 min and the coagulant measurement in the range of 0.5-2 g/l. The optimum Cr(VI) ions removal was gotten at a pH of 7 up to 83.88% in 0.5 g/l of coagulant dose in 40 min. While the optimum Ni(II) ions removal was found to occur at a pH of 5 up to 56.33 % in 0.5 g/l of coagulant measurements in 40 min. The scanning electron microscopy results reveal the difference between the coagulant surface when coagulation. Also, the energy-dispersive x-ray spectroscopy (EDX) analysis shows the presence of Cr(VI) and Ni(II) ions on the surface of the ferrous sulfate after coagulation. Ultimately, the outcomes indicated that ferrous sulfate could be an operative chemical coagulant to remove Cr(VI) and Ni(II) ions from the plating industry wastewater, especially for Cr(VI) particles. The outcome of this study can be a useful guide to the real plating industry wastewater treatment operators.

Using of ornamental plants for phytoremediation of heavy metals (HMs) in soil environments have been grown due to its cheapness and ease of use in urban environments. The aim of this study was to assess the potential use of C. officinalis, for soil copper (Cu) phytoremediation in the presence of different type of chelating agents (Ethylene diamine tetra-acetic acid (EDTA), citric acid (CIT), and tartaric acids (TAR)) in different levels of Cu in a calcareous soil. Moreover, to investigate the effects of stress caused by the use of chelating agents on biochemical changes of C. officinalis, the response of some antioxidant (superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD), and polyphenol oxidase (PPO)) activity of C. officinalis were evaluated. According to the results, C. officinalis showed an increase in shoot and root Cu concentration in the presence of all chelating agents compared to the control. The highest accumulation of Cu in the root/shoot was observed in EDTA-treated plants. However, an increased Cu level in plant parts (due to consuming of EDTA) was corresponded to lower dry weight in shoot and root; higher H2O2 and malondialdehyde (MDA) contents, and antioxidant activity (APX, PPO, CAT, SOD, and POD) in plants compared to the control treatment. On the contrary, the application of CIT and TAR primarily increased shoot and root dry weight and Cu concentration. Altogether, these results could be suggested that plants possess a well-organized resistance mechanism against oxidative stress caused by using of CIT and TAR.

Rice is the most important agricultural crop and the main food material in Gilan and Mazandaran Provinces in northern Iran where organophosphorus pesticides, especially diazinon, are used. The excessive use of this insecticide in paddy fields of Rasht County is a serious threat to people’s health. In this study, 30 rice samples were collected from five zones in the paddy fields of Rasht in summer. The samples were analyzed at the time rice is put on sale to assess the health risk caused by diazinon residues in rice. Following the digestion process, the samples were injected into a high-performance liquid chromatography (HPLC) instrument. Analysis of variance (ANOVA) and one sample t-test were respectively used for analyzing data and the health risk index (HRI) for assessing the risk of rice consumption. According to the results, the mean residual diazinon concentration in the rice crops of the five studied zones at the time of consumption (three months after harvest) was 0.4±0.43 mg kg-1. This was higher than the Iranian standard for permissible diazinon concentration in rice. The results of health risk assessment for rice consumption indicated an HRI value of 0.13 for rice consumption, which did not constitute a serious risk for people who consume rice regularly. Although the results of this study showed that there are no potential health risks for consumers, with increasing use of chemical pesticides for agricultural crops, to achieve food safety, regular monitoring of pesticide residues in agricultural crops is recommended.