This short article, “What the Toad Knows” appears in Jan./Feb. issue of WaterCanada magazine.
WHAT CAN AMPHIBIANS tell us about arsenic levels in groundwater? Iris Koch and a team composed of researchers
from the Royal Military College of Canada and scientists from the Canadian Light Source said frogs and toads could hold the key to arsenic detection in freshwater sites.
The team studied amphibians living in an old mine tailings site near Upper Seal Harbour, Nova Scotia. The animals showed high levels of arsenic after being tested using synchrotron light.
“Any time you have water that’s contaminated, the organisms that are living in the water will likely give you some idea of how toxic the water is,” Koch said. “Organisms might respond in ways that indicate that they are being poisoned.”
While the amphibians appeared to be relatively healthy despite displaying very detectable levels of inorganic arsenic, which is typically toxic, Koch said the biggest outcome of the research is understanding arsenic movement in the environment.
“At the end of the day, looking at a contaminated site like the one in Nova Scotia, we are interested in whether any of the arsenic in the soil and tailings gets into plants and animals,” she said. “We can learn about what animals do with the arsenic in their bodies and this might be helpful in predicting how people might interact with the arsenic, if they were exposed to it.”
Groundwater arsenic contamination is an international health concern since many countries, including China, India, Bangladesh, and Nepal, are dealing with widespread contamination issues. —Staff
In my follow-up research I found the following information on pages 9 and 10 (including a comparison chart) of a report on arsenic found in drinking water in Canadian provinces at – href=”http://www.fraserhealth.ca/media/ArsenicReportSurreyLangley.pdf”
“Arsenic is found in both surface and groundwater, and levels are generally higher in groundwater (Wang & Mulligan, 2006). In Canada, total arsenic levels in drinking water generally fall well below the MAC, although elevated concentrations have been found in areas with natural sources of arsenic. High levels of arsenic have been found in Saskatchewan, Manitoba, Ontario, and Nova Scotia, and in British Columbia (Table 1).
Many of the Canadian arsenic occurrences have been associated with naturally occurring mineralized deposits, usually of volcanic origin. Finding high levels of arsenic in surficial materials is somewhat unusual unless they can be traced to the mineralized source area.”
Well water testing and source protection
Well owners are encouraged to test their water periodically to make sure it is safe to drink. When testing for arsenic,
a “low level” analysis is required to ensure that the minimum detection limit of the analytical method used by the
laboratory is below the drinking water guideline.