The Kentucky Division of Water (DOW) recently completed a public drinking water study to determine potential cancer risks for residents.
According to R. Bruce Scott, commissioner of the Kentucky Department for Environmental Protection, other recent studies have suggested that exposure to high levels of heavy metals like arsenic and chromium may be to blame for Appalachia's high cancer mortality rates.
"Because of these expressed concerns," Scott said, "the agency conducted an extensive analysis of the quality of drinking water in all of Kentucky's public water systems across the Commonwealth."
During the study, researchers examined 12 years of data, from 2000 through 2012, for all of the 519 public water systems throughout Kentucky.
Low heavy metal concentrations in water supplies
"The analysis revealed that heavy metals are not occurring in public drinking water systems at levels that cause health concerns and affirmed that Kentucky's public water supply systems are producing consistently high-quality drinking water," Scott said.
The federal Safe Drinking Water Act requires Kentucky's public water systems to regularly test their drinking water for inorganic chemicals, which include arsenic and chromium, as well as a number of other metals and metalloids.
Arsenic and chromium are elements that commonly occur in soils and rocks, as well as in surface water and ground water.
However, the U.S. Environmental Protection Agency (EPA) has classified both of the substances as known human carcinogens, and has established maximum contaminant levels (MCLs) for them that public drinking water may not exceed.
Results from the DOW study indicated not only that all of the analyzed samples had arsenic and chromium levels below the established MCLs, but also that neither element was detected in any of the samples.
Based on these findings, DOW has determined that there is no correlation between the presence of arsenic and chromium in public drinking water systems and the incidence of cancer in Kentucky.
No evident correlation between cancer and coal production
The study also analyzed the possibility of any relationship between the incidence of cancer and the amount of coal production by using the most recently available cancer information from the National Cancer Institute and comparing it to coal production in Kentucky from 2000 to 2009.
The six highest and six lowest coal producing counties in the Appalachian basin and Illinois basin coal fields in Kentucky were used during the study.
Although coal production varied from year to year over this period, those counties listed as "high" or "low" remained generally the same.
The top six coal producing counties averaged 18,618,225 tons of coal produced per year, and 977 tons of coal was produced for the lowest six coal-producing counties.
According to Dr. Albert Westerman, one of the DOW scientists who conducted the study, the results revealed that coal production does not appear to be a predictive tool for evaluating the incidence of cancer in a county.
"The cancer incidence was not significantly higher in the high coal-producing counties as compared to those that produced relatively little coal," Westerman said.
DOW strives to provide safe drinking water
Lastly, the study demonstrated that public drinking water quality in all regions of the commonwealth was very good and DOW did not identify any regional trends or disparities in drinking water quality.
In addition to the carcinogenic metals, the results for other metals public water systems are required to monitor were analyzed and their concentrations were also found to be at safe levels below the established MCLs for all of the 519 public water suppliers in Kentucky.
Dow Director Sandy Gruzesky said, "The study is part of the ongoing commitment of the division to ensure the public has access to safe drinking water."
Gruzesky said that an estimated 95 percent of Kentucky's population has access to "high-quality" drinking water.
"DOW continues to work with public water systems to facilitate access to potable water to all areas of the Commonwealth to ensure public facilities meet state and federal drinking water standards," Gruzesky said.
While the quality of public drinking water leaving the public water supply systems is of high quality, drinking water quality issues, such as taste, odor, and discoloration problems, can and do occur for an individual user. These issues may result from variations in the source water, issues in the water supplier's distribution system, or home plumbing.
DOW encourages any citizen or business with concerns about the quality of drinking water to contact local water providers.
It is also recommended that citizens read their public water supplier's annual Consumer Confidence Report, which summarizes the public water system's water quality and identifies any compliance issues.
Another DOW report on private drinking water quality will be released in the near future.