A Frozen Legacy Released: Chemical Pollutants in Meltwaters

Kimberley Rain Miner is a Ph.D. candidate in Paleoclimatology at the Climate Change Institute. Her research examines chemical pollutants in glacier melt. Findings from this project will inform management decisions in areas where meltwaters are used for municipal and recreational purposes.

Meltwater streamStarting in the 1950s, chemical substances developed for agricultural and industrial purposes were used widely. These chemicals, such as DDT and PCBs, made their way beyond their intended use and into the environment. By the time they were banned from use for their toxicity, these chemicals had already moved into the atmosphere and spread towards the poles. Washed downward by the rain and snow, chemical residues from legacy pollutants became incorporated into glaciers at northern latitudes, layer by layer. A warming planet now conspires to rerelease the pollutants as glaciers around the world melt. Is this cause for concern?

Kimberley Miner, a Ph.D. candidate at the Climate Change Institute, believes that this topic is worth investigating. “We have nearly 67% of the world population drinking glacier water. It’s important for us to know how much of each type of pollutant is in the glaciers and if the pollutants are going to be carried downstream to the people who consume the water.”

Glacial watersMiner’s research examines the presence and concentration of chemicals in glacial meltwaters. Her work continues a previous study, conducted in 2001, that showed these chemicals to be present, though not in quantities that required remediation. However, meltwater runoff has increased on a global scale and some projections show a continued increase until a peak around the year 2020. As the rate of melt increases, so too does the potential for higher levels of pollutants to be released. Researchers like Miner are asking “is there any chance that if the glaciers melted very rapidly, that this could become a toxic amount?”

To answer this question, Miner has started sampling meltwater streams, as well as a few not fed by glacial water for comparison. As the water is filtered, pollutants in her samples are attracted to the lipid coating on the filters and attach. They can then be chemically analyzed to determine presence and concentration. The time frame for sampling is in July and August, which have been shown by prior studies to have a higher rate of meltwater runoff from deeper layers of the glacier.

Legacy pollutants have been found around the world, in meltwaters from Alaskan mountain ranges, the Swiss Alps and at Mt. Everest. Miner’s research this summer focuses on Banff National Park in Canada. This is an area of interest for both its location at northern latitudes and the presence of high mountain glaciers. Additionally, there are considerable management implications for the use of these meltwaters.

“We’ve got people living downstream, and specifically at Banff, we have a population of 3-4 million people coming every summer to visit. We need to make sure that people are not drinking this water if it becomes toxic.”

Much research has been done on the paleoclimatology aspects of glacier research, but less is known about human impacts. According to Miner, “this was an area that may not currently be affecting downstream populations, but could in the near future, and so, it gives us time to do the research.”

Miner’s interest in this project stems from her environmental management background and a desire to improve understanding of a topic that could become a public health issue. She plans to share the findings from this research with Canadian officials in charge of the park and believes that partnerships between scientists and resource managers have a value from a risk management perspective. This research could be used by officials to inform future mitigation plans, should they be needed.

“I think that’s really the next step for climate scientists, in general, helping with that management component.”

Glacier meltwater lake
Credit: K. Miner

Depending on preliminary results from this summer’s research in Banff, Miner may be returning next summer for additional samples. She also plans to sample glacial meltwaters in China for comparison.

Photo credits: K. Miner
Author: E. Koskela

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