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Legacy of the Tacoma Smelter and its effects on environmental health . For almost 100 years, arsenic, lead, cadmium, copper and other heavy metals were deposited over a 1,000 square mile area in and around Puget Sound by a copper smelter located in Tacoma, Washington.
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Legacy of the Tacoma Smelter and its effects on environmental health For almost 100 years, arsenic, lead, cadmium, copper and other heavy metals were deposited over a 1,000 square mile area in and around Puget Sound by a copper smelter located in Tacoma, Washington. As a result, Asarco (the company held responsible) had to pay a $94 million settlement for cleanup. In 1983, 12 square miles of Commencement Bay, the location of the smelter, was placed on the Environmental Protection Agencies Superfund National Priorities List, partially due to the Asarco smelter.
How can we assess if compounds coming from a location like the Tacoma Smelter are harmful or not? Risk assessment and management framework (from Faustman and Omenn, 2008).
How do these contaminants move through our environment? Exposure pathway schematic (from Faustman and Omenn, 2008)
What has been done to improve the Tacoma Smelter situation? During the last 20 years, the EPA has sampled over 3,500 properties and cleaned up over 2,400 properties. Cleanup has focused on highly contaminated sites, with arsenic readings over 230 parts per million (ppm). The state of Washington has passed lead laws that require soils with contamination over 250 ppm to be cleaned up, and for arsenic contamination in residential areas to not exceed 20 ppm. The Depart of Ecology has set up the Yard Program, to cleanup up residential yards that average over 90 ppm arsenic and will sample any yard that does not already have results within their designated service area.
Agriculture and The Environment Agriculture Has allowed us to expand, but can result in many environmental problems What are some of the Environmental problems with agricultural practices ? What are some of the solutions to these problems? Without Agriculture we would not be able to Sustain the World Population. What is sustainable Agriculture? Can you list any cultures that have successfully used sustainable agriculture and practices they have used to keep soils fertile?
As mentioned in the lecture, the Italians have been adding crop residues to their agricultural soils to sustain productive agriculture. Native Americans of New England and elsewhere would put leftover fish and other materials in their fields, which had a similar effect. Chambers Royal, Hadden and Maslen Compared the Use of Biosolids, Compost and Green Waste Compost as soil amendments on their potential to form top soil. Each added valuable organic carbon and nutrients as well as changing soil properties such as structure. All amendments added around 1g/kg of nitrogen. Biosolids added the most phosphorus,~1g/kg as compared to .6 and .8 g/kg of the other two amendments (important macronutrients). However the Compost and green waste compost added the most organic matter to the soil (about 9 and 7g/kg respectively as compared to only about 4g/kg for the biosolids. Chambers, B., S. Royle, S. Hadden, and S. Maslen. 2002. "The Use of Biosolids and Other Organic Substances in the Creation of Soil-Forming Materials". WATER AND ENVIRONMENTAL MANAGEMENT. 16: 34-39.
