background: due to the increasing pollution of water resources, this study was carried out for evaluation of water quality pollution indices for monitoring of heavy metals (as, zn, pb and cu) contamination in ghahavand plain, hamadan province, western iran during spring and summer 2012. methods: totally, 20 ground water wells were chosen randomly. the samples were filtered (0.45 μm) and maintai...

this study was performed to explore the presence of heavy metals in some popular herbal medicines of the iranian market. primarily, this study was planned to do the task by the usp method. in the second step, those plants which contained more than 10 ppm of total heavy metals were analyzed by atomic absorption method. in this study, 43 popular herbal medicines were investigated according to the...

background: milk is regarded as a unique source of food for all ages. when milk is exposed to various contaminants, including lead and cadmium, it is considered a risk to humans. the presence of some metal pollutants, especially cd and pb, facilitates their entry into the food chain and thus increases the possibility of their toxic effects on humans and animals. therefore, we decided to check l...

background: the removal of toxic metals from sewage and wastewaters is one of the most important concerns in the twenty first century. the removal of poisonous cr(vi) from aqueous solution by different low-cost available nanoporous adsorbents was investigated in the present study.  methods: fumed silica, bentonite (bn), hydrotalcite (ht), mcm-41, na-y, mordenite (mor) and sapo-34 were used at d...

How Mining Releases Toxic Metals Large amounts of waste rock and tailings contaminated with toxic metals can be produced by mine sites. In the case of the Donlin Creek mine, there are only 0.072 ounces of gold for every ton of ore, a figure that does not take into account the waste rock. Toxic substances contained within the rock and tailings are more easily released once these substances are p...

The heavy metals chiefly include Pb, Hg, Cd, Cr, Cu, Zn, Mn, Ni, Ag, etc. The heavy metals, viz., As, Cd, Pb and Hg are considered most toxic to humans, animals, fishes and environment. Excessive concentrations of heavy metals are detrimental. They destabilize ecosystems because of their bioaccumulation in organisms, and toxic effects on biota and even death in most living beings. All heavy met...

There is growing evidence that micronutrient intake has a significant effect on the toxicity and carcinogenesis caused by various chemicals. This paper examines the effect of micronutrient status on the toxicity of four nonessential metals: cadmium, lead, mercury, and arsenic. Unfortunately, few studies have directly examined the effect of dietary deficiency or supplementation on metal toxicity...

Contamination of soils, water, and sediments by radionuclides and toxic metals from uranium mill tailings, nuclear fuel manufacturing and nuclear weapons production is a major concern. Studies of the mechanisms of biotransformation of uranium and toxic metals under various microbial process conditions has resulted in the development of two treatment processes: (i) stabilization of uranium and t...