Abstracts: ISEE 22nd Annual Conference, Seoul, Korea, 28 August–1 September 2010: Water Pollution - Exposure to Metals, Emerging and Remerging Diseases
Australia has an increasing number of open cut mines with over 1800 in Western Australia. When mining ceases, a large open void may remain and become filled with water to form a pit lake. These lakes are known to become acidic or hyper saline. Coal has been mined in the Collie area in the South West of Western Australia since 1898. Pit lakes have been present in the area for approximately 50 years since mining began.
There are 3 main lakes used by the regional public for recreational purposes, including swimming, fishing, and boating and water quality varies between them. We collected water quality data for the lakes.
Lake pH is typically low (3.8–6.8) due to acid mine drainage from sulphide rich materials such as pyrite. Water temperature ranges from 12.5°C to 28.9°C. Concentrations of Hg were above Australian Drinking Water Guidelines (mean, 171 μg/L; range, 100–240 μg/L) at Black Diamond. The detection limits for other pollutants were above the Australian Drinking Water Guidelines making interpretation difficult. At the other 2 lakes, Lake Kepwari and Stockton Lake respectively concentrations of Al (means 3577 and 529 μg/L), Ni (means 90 and 25 μg/L); Pb (means 33 and 59 μg/L); and As (means 38 and 19 μg/L) were also above drinking water and some recreational water quality guidelines. Sampling of lake aquatic biota indicates a regular summer presence of mosquito larvae (Culex sp. with the likely presence of other genera) and biting midges, which may be transmitters of vector-borne diseases. Further testing is required to determine which species is present.
A preliminary risk assessment based on the results of recreational use of the lakes, and water quality parameters suggests a potential for health impacts in users depending on the frequency and type of lake-based activities.