ABSTRACT
Background and Aim: Fish are considered as one of the main aquatic organisms in the food chain. They have the potential to accumulate large amounts of heavy metals in their tissues. The purpose of this study was to measure the levels of five heavy metals [Cd, Pb, Cu, Cr, and Zn] in the gill, liver, and muscle tissues of common carp, Capoeta trutta, and Grass carp in the Gamasyab River in 2015 as well as bioaccumulation study and hazard quotient determination [HQ]
Material and Methods: This was a cross-sectional study in which three species of fish in the Gamasyab River were caught in autumn and winter. The tissue preparation method was chemical digestion. Concentrations of heavy metals were measured using an ICP apparatus. Data were analyzed using SPSS version 16
Results: Permissible limits of ingestion of heavy metals per day through consumption of the three aforementioned fish for an adult person with mean body weight of 70 kg were 0.021, 0.18, 3.5, 13.3, and 20.4 micrograms for cadmium, lead, chromium, copper and zinc, respectively, in this study. The Hazard Quotients [HQ] index was below 1 for all heavy metals
Conclusion: The Hazard Quotients [HQ] index of fish consumption in this study was less than 1 and indicated that consumption of these fish was harmless. But since heavy metals have the property of bioaccumulation, seasonal monitoring of heavy metals in this region is essential
ABSTRACT
Background: The present study investigated the effect of the Middle East dust storm episodes on the concentration and composition of PM[10] during April to September 2013 in Sanandaj City, western Iran
Methods: Sampling was once every six days, and on dusty days using an Omni air sampler. The PM[10] sample was collected on polytetrafluoroethylene filters. Average of 24 h values of PM[10] mass concentrations was determined. Half of each sample filter and blank filter was analyzed for water -soluble ions and the other half was digested for metal analysis
Results: The average PM[10] concentration was 160.63 micro g/m[3]. The lowest and highest concentrations of PM[10] were in May and June respectively. The average PM[10] concentration during the non-dusty days was 96.88 [micro g /m[3]]. Nevertheless, it increased by 4.8 times during the dusty days. Ca[2+], Cl[-], NO3[-], and Na[+] accounted for 71% of total water-soluble ions on the dusty days. During the dusty days, the dominant elements in PM[10] were Na, Ca, Mg, Al, and Fe contributing to 95.72% of total measured metals. The correlation coefficient and enrichment factor analysis have shown that on dusty days, Al, Ca, Fe, K, Mg, Na, Sr, and V were the elements with the crustal sources
Conclusions: Concentrations of PM[10] during dusty days were considerably higher than that during non-dusty days. In addition, concentrations of water-soluble ions and metals were also higher during dusty days
Subject(s)
Middle East , Dust , Metals , Air PollutionABSTRACT
Safety programs are a core part of safety management in workplaces that can reduce incidents and injuries. The aim of this study was to investigate the influence of Safety Training Observation Program [STOP] technique as a behavior modification program on safety climate in a construction company. This cross-sectional study was carried out on workers of the Petrochemical Construction Company, western Iran. In order to improve safety climate, an unsafe behavior modification program entitled STOP was launched among workers of project during 12 months from April 2013 and April 2014. The STOP technique effectiveness in creating a positive safety climate was evaluated using the Safety Climate Assessment Toolkit. About 76.78% of total behaviors were unsafe and about 54.76% of total unsafe acts/ at-risk behaviors were related to the fall hazard. The most cause of unsafe behaviors was associated with habit and unavailability of safety equipment. After 12 month of continuous implementation the STOP technique, 55.8% of unsafe behaviors reduced among workers. The average score of safety climate evaluated using of the Toolkit, before and after the implementation of the STOP technique was 5.77 and 7.24, respectively. The STOP technique can be considered as effective approach for eliminating atrisk behavior, reinforcing safe work practices, and creating a positive safety climate in order to reduction incidents/injuries
ABSTRACT
Increased environmental pollution caused by toxic metals is a great concern because of their carcinogenic, non-biodegradability and bio-accumulation properties. Cadmium [Cd] and copper [Cu] are two of the most common heavy metals in the environment. The objective of this study was to assess the effect of modified wheat straw promoted by sodium bicarbonate for removal of cadmium and copper from aqueous solution. Adsorption process was accomplished in a laboratory-scale batch with emphasis on the effect of various parameters such as pH, contact time, arsenic concentration and adsorbent dosage on adsorption efficiency. In order to understand the adsorption process, equilibrium isotherms were also determined. The results of this study showed that adsorption of the Cd and Cu was influenced by several parameters such as arsenic initial concentration, adsorbent dosage and solution pH. Maximum adsorption efficiency was achieved at a pH of 7. The adsorbed amount of metal ions increased with the initial concentration of the metals. Among the isotherm models tested, i.e., the Langmuir, Freundlich, and Dubinin Radushkevich, the adsorption equilibrium of both Cd and Cu was best described by the Langmuir and Freundlich models. Mean values of the free energies of adsorption [11.1 kJ mol-1 for Cd and11.4 kJ mol-1 for Cu] indicated that adsorption of Cd and Cu ions by wheat straw might follow a chemisorption mechanism. We concluded that adsorption by modified wheat straw is an efficient and reliable method for removal of Cd and Cu from aqueous solutions