Compounds within hexavalent chromium are considered occupational carcinogens by the National Institute for Occupational Safety and Health; short term exposure can harm eyes, skin, and the respiratory system, while prolonged and extensive exposure can lead to the onset of cancer.
Heavy use of hexavalent chromium leads to large quantities of the heavy metal being discharged in to the environment despite the efforts of water treatment facilities, unfortunately the water pollutant ends up contaminating sources of drinking water for more than 200 million people within the USA alone.
Vitamin C may be the most well known antioxidant and epigallocatechin gallate is the most abundant antioxidant found within green tea.The natural antioxidant effects of vitamin C and epigallocatechin gallate were tested against hexavalent chromium in a study conducted by Olivet Nazarene University researchers, who reported the antioxidants appeared to inhibit the toxic effects.
During the first phase of this study two different types of human cells were cultured and exposed to varying concentrations of hexavalent chromium, of which both displayed cytotoxic effects after being exposed to at least 200 parts per billion of the heavy metal. During the second phase either 10 parts per million of vitamin C or 15 ppm of epigallocatechin gallate were applied to cell cultures, after being treated the cells were exposed to increasing levels of hexavalent chromium.
Treating human cell cultures with either of the tested antioxidants was reported to protect the cultured cells from the cytotoxic effects of hexavalent chromium; exposure to more than 200 ppb of hexavalent chromium did not cause harm after treatment. Neither of the tested antioxidants harmed the cells which confirmed the safety of their use in humans.
In separate studies bacterial cultures underwent exposure to at least 20 ppb of the toxic heavy metal; minimum concentration measured 10% of the cytotoxic level for human cells which proved harmful enough to cause mutation in the DNA of the bacteria. 20 ppm of vitamin C was applied to bacterial cultures which were then exposed to at least 20 ppb of hexavalent chromium, the treatment was found to protect the microbes from DNA damaging effects of the toxic heavy metal.
Findings indicate that the toxic effects of hexavalent chromium were caused by an oxidative reaction which was stopped by the antioxidants, thereby suggesting that antioxidant based approaches may help to treat water contaminated by hexavalent chromium and its chemical compounds as a potential way to protect public health, and help to guide monitoring and regulation of water quality.
