Wednesday, December 11, 2013

A Killer Shine: Spotlight on Chromium

Images from Wikipedia Commons

   Chromium is a highly toxic chemical used in the production of Stainless Steel to prevent iron from rusting. When electro-plated onto other metals, it becomes chrome. In 2010, Chromium was rated by as the third greatest toxic threat to the globe, with an estimated 7.3 million people at risk within their identified pollution sites and an estimated 13-17 million worldwide. These numbers, and this degree of chromium pollution however, doesn't come from stainless steel production, but rather, the majority of this industrial waste spews from tanneries. Although the role of Chromium in tanning is something about which EcoPol has previously written, the degree of danger posed by the compound requires a second look. 
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   Chromium salt, usually Trivalent Chromium, CR(III), is used to tan leather by causing the collagen within the animal hide to be cross-linked, helping the leather to take on a tougher, hardier quality. Though the chromium used in the production of tanned leather is of the Trivalent variety, CR(III)  and as a result, is considered far less harmful than Hexavalent  Chromium CR(VI), as a Bangladesh University of Engineering and Technology report authored by Avit Kumar Bhowmik and M. Samiul Islam discloses, under the heat and pressure found within the tanneries, as well as within the soil into which the toxic Chromium seeps, the mostly harmless Trivalent Chromium quickly changes its molecular structure, and forms Hexavalent Chromium, CR(VI). Hexavalent Chromium, Cr(VI), is toxic and carcinogenic, and can be mutagenic when inhaled. In a 2001 WHO report, the Hazaribagh tanneries employ over 8,000 workers who suffer from dermatological, gastrointestinal, and other diseases, while over 90% of their total employees die before the age of 50.
   These numbers, certainly, are shocking, and beg the question: why is it that work requiring chemicals as toxic as chromium being done in nations so impoverished, within facilities that lack the infrastructure necessary to properly filter and prevent the spread of these toxins? The answer, of course, much like the problem, is complex and interwoven, as the EcoPol project has previously detailed. As we at the EcoPol project have also previously written,  the stability and economic state of these nations leave them particularly susceptible to bribery, but the poverty of the nations has another draw; low income areas mean low income workers who are willing to do more, and take more risks for far less pay. The result? Areas like Hazaribagh make prime locations for cheap leather due to the low overhead. Although this cost may be negligible in dollars, as previously detailed by the EcoPol project, the remaining balance is paid in health risks and deductions from the quality of human life.

   These low labor and material costs have led to the majority of the world's tanning activity to occur in low and middle income nations. The cost savings in legal currencies add up to low levels of environmental protection, low amounts of filtration and environmental restoration, and little to no care or concern given to the well-being of the employees. The low costs overall trickle down to low costs spent on environmental protection and  as a result, the toxins trickle out of the refineries. Chromium exposure affects most of the workers through inhalation at the work site, and those around the tanneries are, in turn, poisoned as the Chromium effluent seeps into the nearby rivers and streams, leeches into the topsoil, and makes its way into ground water and drinking water supplies. These local rivers and streams are then used for bathing, dish and clothes washing, and sometimes by children for swimming.
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  Chromium pollution is also caused by the large amounts of skins, hides, and fats that are dumped onto riverbanks and fields nearby populated areas, causing further pollutants to leech into the soil, such as cadmium, nickel, and lead. These toxins, alongside chromium, can, as they mix with water, then make their way into crops that have been watered with the contaminated water sources. These chromium-laden solid wastes, such as the skins and fats, are also often converted to chicken feed, which then contaminates livestock and the humans who eat the tainted meat. Another route of chromium exposure through food sources comes when the water polluted with chromium seeps into the seas and rivers, contaminating the area's fish and shellfish, which are often a food source for the local populations.

   Chromium pollution and the horrific human effects it causes is a major problem caused by tanneries. Much like the EcoPol project wrote about China,  the main vector by which this poison is spread is the water. And also like in China, these pollutants, once in the waterways, continue to cause widespread repercussions as the pollutants circulate and are bathed in, drank, and eaten. However, there is hope. The Blacksmith Institute has had success using electron donors into well water which converts Hexavalent Chromium, Cr(VI) to the less toxic Trivalent Chromium, CR(III). Further treatments, such as bone charcoal, and salt-tolerant bacteria, introduced into the contaminated soil areas, can further reduce the amount of chromium that has been absorbed into the land. In combination with these treatments, secured landfills and waste treatment facilities can further greatly reduce the health risks posed by this killer compound. 

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