The strategies for reduction of carcinogenic factors exposure can reduce the risk of most cancer types. Millions of people around the world get exposed to high levels of heavy metals in the drinking-water. Therefore, quality control in drinking-water and detection of its heavy metals is extremely critical issue. The carcinogenicity of aluminum, arsenic, chromium, nickel and selenium has been documented previously, but in a scattered fashion. Trace amount of these elements can induce genetic and epigenetic alterations in different cancer-related genes of somatic and stem cells, thus involved in cancer stem cell formation. Through epigenetic effects of these elements have more prominent role than their genetic effects, these elements are able to change the pattern of cancer-related genes expression profiles, too. Therefore, understanding the underlying epigenetically mechanisms of these trace elements can reduce their toxicities duo to individual and social preventive behaviors. It seems that the toxic effects of these elements in many regions are predictable, but antioxidant supplements eliminate the reactive oxygen species as leading effects of these elements.