On May 24, 2010, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this false-color, high-resolution view of the very tip of the Mississippi River Delta. Ribbons and patches of oil that have leaked from the Deepwater Horizon well offshore are silver against the light blue color of the adjacent water. Vegetation is red.
Our oceans are generally resilient in the wake of contamination such as industrial waste, in part due to the highly effective filtration by deep sediments that can "bury" the toxins. Of course, there are limits. The BP Oil Spill is an alarming example. What happens when the ocean's filtration system, a delicate balance of sediments working together, are shut down?
Not surprisingly, wastewater generated from oil production can be quite toxic. An unappealing cocktail of toxins including heavy metals, this water contains high levels of mercury, lead, cadmium and arsenic. Of particular concern is arsenic: such waste can contain up to one hundred thousand times the safe limit in drinking water set by the Environmental Protection Agency. About two liquid ounces of contaminated wastewater consumed by a 150 pound person in one day corresponds to a lethal dose.
Fortunately, oil rig wastewater is not a beverage of choice and sediment filtration in our oceans can effectively "eliminate" the waste or least minimize any leaching.
British scientists recently conducted a study of the effect of crude oil on how ocean sediments can filter out toxic chemicals such as arsenic. They found that arsenic absorption within sediments is significantly reduced when exposed to oil. With the filtration system essentially shut down, arsenic can then be dispersed freely affecting the entire food chain, including us.
Potential dangers of arsenic-contaminated water are reminiscent of Bangladesh, with widespread reports of skin lesions and a higher incidence of cancer. Drinking water in Bangladesh is widely recognized as an environmental and public health nightmare, having poisoned up to 77 million residents, resulting from the widespread use of groundwater. Hand-pumped wells can access water containing extremely high levels of arsenic leached from rocks, not to mention contamination from mining and industrial production plants. Indeed, the World Health Organization has referred to this as "the largest mass poisoning of a population in history".
(Note: You can view every article as one long page if you sign up as an Advocate Member, or higher).
2
1
1
