Journal of Advances in Environmental Health Research
Year:2014 | Volume:2 | Issue:2|Papers Count:8

The most frequent and expensive cause category of compensable loss is manual material handling (MMH). Casting workers who handle oxygen (O2) cylinders manually are at risk for work-related musculoskeletal disorders (WMSDs). The aim of this study was to assess manual handling of O2 cylinders by casting workers and to implement ergonomic intervention to reduce the risk of musculoskeletal disorders (MSDs). This interventional study was conducted on 30 male workers of casting unit in a steel industry. Nordic Musculoskeletal Questionnaire was used to determine the prevalence of MSDs in workers. Snook tables and its software were used to assess manual handling risk of O2 cylinders. Manual handling of O2 cylinders was totally excluded using the box with 16 cylinders that can be moved by crane. The most common MSDs in 1 year prior to the study were low back pain (43%), shoulders (33%), and hand/wrist and knee disorders (16%), respectively. The Snook tables’ results indicated that 86% of lifting/lowering, 100% of carrying, and 50% of pulling tasks were appropriate for<10% of casting workers. About 94% of O2 cylinders pushing were appropriate for 17% casting workers. With the implementation of ergonomic intervention, the risk of WMSDs and explosion of cylinders was decreased, and safety of workers was improved.

Corrosion in general is a complex interaction between water and metal surfaces and materials in which the water is stored or transported. Water quality monitoring in terms of corrosion and scaling is crucial, and a key element of preventive maintenance, given the economic and health hurts caused by corrosion and scaling in water utilities. The aim of this study is to determine the best model for zoning and interpolation corrosive potential of water distribution networks. For this purpose, 61 points of Sanandaj, Iran, distribution network were sampled and using Langelier indices, we investigated corrosivity potential of drinking water. Then, we used geostatistical methods such as ordinary kriging (OK), global polynomial interpolation, local polynomial interpolation, radius-based function, and inverse distance weighted for interpolation, zoning and quality mapping. Variogram analysis of variables was performed to select appropriate models. The results of the calculation of the Langelier index represented scaling potential of drinking water. Suitable model for fitness on exponential variogram was selected based on less (residual sums of squares) and high (R2) value. Moreover, the best method for interpolation was selected using the mean error and root mean square error. Comparison of the results indicated that OK was the most suitable method for drinking water quality zoning.

The ash content formed after burning of materials in indoor may be harmful to environment on dumping due to high ionic and metallic concentration. Therefore, the chemical composition of various indoor ash residues derived from burning of the biomass (BM), coal (C), cow dung (CD), incense (IS) and mosquito coil (MC) materials is described in this study. Three samples each of BM, coal, CD, IS and MC materials were burnt. The ash residues were collected and sieved out the particles of mesh size£0.1 mm size. The Cl-, NO3-, SO42-, Na+, K+, Mg2+, Ca2+ content (n=15) was ranged from 0.12-8.27, 0.01-0.64, 0.74-12.53, 0.06-4.47, 0.29-15.45, 0.30-2.51 and 0.68-19.05% with mean value of 1.81±1.18, 0.10±0.08, 3.31±1.66, 1.05±0.70, 4.92±2.04, 1.27±0.36 and 7.68±2.94%, respectively. The composition of metals, that is, Fe, Cr, Mn, Ni, Cu, Zn and Pb (n=15) was ranged from 1100-24, 600, 12-211, 109-1102, 5-142, 21-145, 25-244 and 5-42 mg/kg with mean value of 95±31, 474±152, 43±23, 75±23, 107±32 and 16±6 mg/kg, respectively. The enrichment and fluxes of ions and metals of indoor ash residues are described.

Natural organic matter (NOM) affects some qualitative parameters of water such as color. In addition, it can deteriorate the performance of water treatment process including coagulation, adsorption, and membranes. NOM also reacts with chlorine in the chlorination process and may form disinfection by-products. The present study was carried out in laboratory-scale in a batch system using a cylinder shape reactor with effective volume of 2 l. The initial NOM concentrations during the study period were 10, 25, and 50 mg/l. After specific time intervals, samples were taken from the reactor and filtered. Finally, the NOM removal according to total organic carbon (TOC) content of the samples that were analyzed with a TOC analyzer. The results showed that the highest NOM removal efficiency for three initial concentrations 10, 25, and 50 mg/l were 91, 94, and 82%, respectively. These removal efficiencies were obtained at pH 7, contact time of 20 min, and electrical current of 0.1 A. The electrical energy consumption was 0.08, 0.06, and 0.03 kWh/m3, respectively. In this study, the application of electrocoagulation (EC) treatment method using combined Al and Fe electrode was examined to remove NOM from aqueous solution. Based on the obtained results, the EC can be used as an effective method for removing NOM from aqueous solution.

Dyes are widely used in various industries most of them are not readily biodegradable and are consisted of number of toxic, mutagenic, and carcinogenic compounds. Therefore, it is essential to remove them from effluent before their discharge to the environment. The objective of this investigation was to synthesize copper oxide (CuO) doped zinc oxide (ZnO) nanoparticles under mild hydrothermal conditions using CuO as dopant and triethylamine as surface modifier to remove acid black 1 from aqueous solutions. Synthesized nanoparticles were characterized using powder X-ray diffractometer, Fourier transform infrared spectroscopy, scanning electron microscopy, and ultra violet-visible spectroscopy. The central composite design matrix and response surface methodology (RSM) were applied for designing the experiment, evaluating the effect of variable and modeling the degradation of acid black 1 dye. The results obtained from analyses of variance indicated that our experiments were fit with quadratic model. Moreover, the optimization R2 and R2 adjusted correlation coefficients for model were evaluated as 0.94 and 0.89, respectively. The optimal conditions for high efficiency (100% dye removal) was found to be at catalyst dosage of 1g/l, dye concentration of 50 mg/l, and pH=6. This investigation introduced the RSM as an appropriate method to model and optimizes the best operating condition for maximizing dye removal. In conclusion, the results showed that nanoparticals dosage plays crucial role in this regard.

Removal of toxic heavy metals from wastewater is an important environmental challenge. In this Study, Zn (II) removal from aqueous solution by chitin extraction from crustaceous shells (shrimp and crab) was investigated. The biosorption studies were determined as a function of contact time, pH, initial metal concentration, and the amount of adsorbent. Adsorption of Zn (II) increased with decreasing concentration of the adsorbents and reached maximum uptake at 0.5 g. Effect of pH was studied in the range of 3-7 and the optimum conditions for both adsorbents were found in the range of 5-7. Zn (II) adsorption for both adsorbent was evaluated by Langmuir and Freundlich Isotherms. Results indicated that the Freundlich isotherm model was the most suitable one for the adsorption process using chitin extracted of shrimp and crab shells. The pseudo-first order and pseudo second order kinetic models were used to describe the kinetic data. The adsorption capacity (qmax) calculated from Langmuir isotherm and the values of the correlation coefficient obtained showed that chitin extracted from shrimp shells has the largest capacity and affinity for the removal of Zn (II) compared with the chitin extraction from the crab shells.

Dental offices produce a variety of dangerous wastes during normal business day. Most of these waste are nonhazardous that can be managed as household wastes; however, some component are hazardous and can pose a risk to human and the environment if discarded to Municipal Solid Wastes. These types of wastes must be managed separately. Therefore, the aim of this study was to assess the component and production rate of dental waste in Sari city, northern of Iran in 2011-2012. A descriptive cross-sectional study was conducted on 64 private dental practices from 146 available dental clinics in Sari city using a checklist and questionnaires which contain 25 questions and items. Dental wastes were weighed to determined qualitative and quantitative analysis. The data were analyzed using SPSS and MS-Excel. The results indicated that 77% of produced wastes were non-hazardous. The acceptable level management was observed only in 3.7% offices. The most desirable element management was accurate collecting (30.88%) in these offices. In general, it can be concluded that there is no proper management of wastes in dental centers of Sari. The mercury recycling is required for optimal management of dental waste. Furthermore, the dentists’ education must be takes place to perform the management activities including reduction, separation and recycling inside the office.

Biofilm is communities of microorganisms attached to the surface and is able to concentrate metal species within their cell structure. Therefore, the aim of this study was to produce Escherichia coli biofilm on zeolite (clinoptilolite) and evaluate its ability for nickel (Ni) and chromium (Cr) adsorption from aqueous solutions. A laboratory-scale batch model was used for biodsorption assay. The effect of initial metal concentrations and pH on the removal efficiency was studied. Two isotherm equations were used for analyzing the experimental data. The results showed that Ni uptake by biofilm were higher than Cr. The biosorption process was best described by the Langmuir model. Fourier transform infrared confirmed that there are some functional groups on the biomass surface that may interact with the metal ions. It is concluded that the biofilm is very promising for the removal of metal ions from aqueous solution and hence may be encourage the utilization of biofilm in environmental applications.