Generally, beach violations during a swim season were below 15% o

Generally, beach violations during a swim season were below 15% of all samples collected until 1990 and then violations began increasing to approximately 20%. Wastewater and stormwater infrastructure changes, precipitation and lake see more levels were likely associated with these trends and further analyses are warranted. Human health in relation to the LSC water quality is possibly one of the most pressing issues that demands better understanding of the linkages in the CHANS framework. Generally, LSC was and still is considered to have high water quality (David et al., 2009, Herdendorf et al., 1993, Leach, 1972, Leach, 1991 and Vanderploeg et al.,

2002) because of the large input (98%) of Lake Huron water via the St. Clair River which has low nutrient concentrations. For example, the mean total phosphorus concentration was 9.10 μg L− 1 (± 0.51 std. err, n = 85) PS-341 and the mean total Kjeldahl nitrogen concentration was 183.5 μg L− 1 (± 8.0 std. err, n = 85) from samples collected near the mouth of St. Clair River between 1998 and 2008 (data source: Michigan Department of Environmental Quality). Any future changes to Lake Huron will have a direct impact on LSC (Leach, 1972). Runoff from agricultural activity in the LSC watershed, especially from the eastern and western rivers (e.g. Clinton, Sydenham, and Thames) is the

major source of nutrients into the lake and the longer resident time of the southeastern water mass compared to the northwestern promotes higher biological production (Leach, 1972, Leach, 1973 and Leach, 1991). Past studies indicate four rivers, the Thames and Sydenham Rivers in Ontario

and the Clinton and Black rivers in Michigan contributed Low-density-lipoprotein receptor kinase significantly to the non-point source nutrient pollution (Lang et al., 1988 and Upper Great Lakes Connecting Channel Management Committee, 1988). A model analysis of average total phosphorus loads to LSC indicated that the average phosphorus load inputs equaled the outputs during their 1975–1980 period and suggested that the lake was not acting as a sink for phosphorus (Lang et al., 1988). An updated analysis is needed for the current contributions of point and nonpoint phosphorus loading into and out of LSC. PCBs, organochlorine insecticides, DDT, and mercury were released from historic chemical–industrial sources located on the major tributaries, such as St. Clair River that drain to LSC (Fimreite et al., 1971, Gewurtz et al., 2007 and Leach, 1991). The LSC fishery closed from 1970 to 1980 when high levels of mercury were discovered in fish tissues and the low economic returns prevented a rebound in the commercial fishery (Leach, 1991). In the early 1980s lead, cadmium, and octachlorostyrene were found in clams that were downstream from the St. Clair River suggesting it was a primary source of these contaminants (Great Lakes Institute, 1986, Leach, 1991 and Pugsley et al., 1985). The Clinton River was also found to be a source of PCBs in clams during this study.

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