Presentation on theme: "Sydney Tar Ponds: Toxic Chemicals and Their Effects The Sydney tar ponds are the result of the operation of a steel plant and coke ovens in Sydney, Nova."— Presentation transcript:
Sydney Tar Ponds: Toxic Chemicals and Their Effects The Sydney tar ponds are the result of the operation of a steel plant and coke ovens in Sydney, Nova Scotia. The site was operational from 1901 until 1988, when it was shut down. During it’s final years of operation the site was owned by a provincial crown corporation, Sysco. It is believed that during most of the time that the plant was operating, those running the operation and those working at the site were unaware of the possible health, safety and environmental threats created by the production and its by- products. It is also believed that there was no program in place to ensure proper handling and disposal of hazardous wastes at the coke ovens while they were operational, since no information or documents currently remain to support the existence of such a program (Furimsky, 872). Map of Tar Ponds and surrounding communities
Steel Plant and Coke Ovens Solid Sediment The gaseous emissions from the plant have long since dissipated and do not contribute to the current environmental conditions and health problems experienced in the area surrounding the coke ovens and steel plant. However, the solid and semi-solid waste still persists and has led to devastating environmental and health consequences for the surrounding communities. During the production of coke, coal was heated in furnaces and eventually the coke was separated from the tar and other unwanted by products. This tar and particulate matter was poured off into a nearby brook and eventually collected in the Muggah Creek estuary, contaminating both the ground and the groundwater in the area. In the end by- products from the coke ovens and steel plant, that at one point provided Canada with up to half of it’s steel, resulted in over 700 000 tonnes of contaminated sediment covering an area of 77 acres ( Furimsky, 872. Images of the Tar Ponds. Top: Ariel view. Left: A stream entering the Tar Ponds. Bottom: Tar Pond.
Toxins in the Tar Ponds The sediment that makes up the tar ponds has been found to contain BTEX (Benzene, toluene, ethylbenzene and xylenes), polycyclic aromatic hydrocarbons, polychlorinated biphenyls and particles containing toxic metals such as arsenic and lead (Furimsky, 872). Residents of the communities surrounding the tar ponds have higher incidences of cancer, cancer mortality and congenital abnormalities when compared with residents in the rest of Nova Scotia and Canada (Lambert and Lane, 35). They also complain of massive head aches, nose bleeds and breathing problems (Tracking the Tar Ponds). The health effects that can be caused by these toxins are as follows: BTEX: Benzene is a carcinogen and can cause acute toxicity effects including dizziness, rapid heart rate, confusion and tremors. Long term exposures can lead to anemia because of its effect on bone marrow and red blood cell production, as well as increased risk of infection from a decreased immune response. Toluene effects the nervous system and results in people seeming like they are drunk from alcohol and can effect your kidneys in high doses. Ethylbenzene is a possible human carcinogen and has been shown to cause ear damage in animals as well as damage to the kidneys from long term exposures. Toluene in high level exposures can cause dizziness, confusion and changes in balance as well as possible changes to the liver and kidneys (Xylene).
Toxins in the Tar Ponds Polycyclic Aromatic Hydrocarbons: Animals who ingested PAHs have been shown to have difficulty reproducing as have their offspring and they also have higher rates of birth defects and offspring with lower body weights. Animal studies have also shown that PAH exposure decreases the ability to fight disease and it is a suspected carcinogen (Polycyclic Aromatic Hydrocarbons). Polychlorinated Biphenyls: PCBs cause skin conditions like acne as well as liver damage. In animals it has been shown to cause liver, stomach and thyroid damage as well as anemia and behavioral changes. PCBs are also associated with cancer of the liver and biliary tract in humans (Polychlorinated Biphenyls). Lead: 1-15% of the children in the communities surrounding the tar ponds are predicted to have lead concentrations above the recommended value of 10μg/dL. Lead leads to lower IQs in children. In adults it can lead to increased blood pressure, fertility problems, nerve disorders, irritability, muscle and joint pain as well as memory and concentration problems (Lead and Your Health). Arsenic: Arsenic is a carcinogen and when found in drinking water it can cause nausea, decreased red blood cell production, thickening and discoloration of the skin, numbness in the hands and feet and an abnormal heart rate along with blood vessel damage (Government of Canada). Above: Sludge seeping through a cellar wall in a home near the tar ponds.
Clean Up Efforts Attempts have been made to clean up the tar ponds over the years, but they were all costly and ineffective and therefore quickly halted. Now both the federal and provincial government have agreed on a clean up program that is currently underway. The governments are splitting the costs of the projected $400 million cleanup project (Leckie). The process chosen includes stabilization to make the compounds less toxic, less soluble and less mobile followed by solidification by mixing the sludge with cement and other hardening agents. The stabilization and solidification process began in October 2009. As part of the clean up process cut off walls and a surface cap will also be installed to prevent further contamination and once the sludge is stabilized and solidified it will also be capped. The ground water at the site will be treated as well (Sydney Tar Ponds Agency). While this clean up project seems to have gone farther than any other attempt in the past, it is still not without controversy. Some question whether the methods used, which have not been extensively tested, will in fact solve the problem (Leckie), while others believe the scope of the project, which just includes the site and a few residential properties, is too narrow. A study by Timothy Lambert and Stephanie Lane has shown that all three of the communities surrounding the tar ponds, which are Whitney Pier, North End and Ashby had statistically different levels of lead, arsenic and PAHs when compared to background samples and that at these levels these compounds can cause adverse effects and therefore all three areas should be considered for remediation, but currently only part of one area is. Left: Ariel shot of clean-up process Right: Clean up At the tar ponds site * References provided on the back of this paper*
Works Cited: Furimsky, Edward. "Sydney Tar Ponds: Some Problems in Quantifying." Environmental Management. 30.6 (2002): 872-879. Print. Government of Canada. Arsenic in Drinking Water. Ottawa:, 2001. Web. 8 Nov 2009.. Lambert, Timothy W., and Stephanie Lane. "Lead, Arsenic, and Polycyclic Aromatic Hydrocarbons in Soil and House Dust." Environmental Health Perspectives. 112.1 (2004): 36-41. Print. Leckie, John. "Ten years to clean up Sydney Tar Ponds." Journal of Commerce 28 May 2007: n. pag. Web. 8 Nov 2009.. "Project." Sydney Tar Ponds Agency. Sydney Tar Ponds Agency, Web. 8 Nov 2009.. "Tracking the tar ponds." CBC News Online 06 May 2004: n. pag. Web. 8 Nov 2009.. United States. Lead and Your Health. Triangle Park:, 2005. Web. 8 Nov 2009.. United States. Polychlorinated Biphenyls., 2001. Web. 8 Nov 2009.. United States. Polycyclic Aromatic Hydrocarbons., 1996. Web. 8 Nov 2009.. United States. Xylene., 2007. Web. 8 Nov 2009..