By ANDREW CREMATA
A coal burning plant in China pumps emissions into the atmosphere, part of which includes mercury, an element harmful to humans. Mere hours later, wind currents carry the airborne pollutants across the Pacific Ocean into the region of Alaska, Canada, and the arctic. Weather patterns and rainfall cause toxins to settle into soil, sediment, rivers, and streams where tiny organisms feed. Larger animals feed on the smaller, and as the food chain becomes shorter, mercury levels in animals toward the top become more concentrated. What was born many thousands of miles away eventually finds its way into the food on the plates in which we, as humans, eat.
Just how contaminates make their way from places across the globe into the arctic was discussed by Dr. Haley Hung of Toronto at the National Park Service auditorium on Feb 18, in a presentation entitled International Atmospheric Transport of Pollutants to the Arctic (INCATPA). The catchy title is also the name of an international collaboration designed to globally monitor changes to the arctic caused by the release of mercury and persistent organic pollutants, like pesticides and combustion engine emissions.
The project will continue to collect data started from the Northern Contaminates Program, which began in the 1990s. Hung explained that the arctic environment is more susceptible to change, and in turn, changes in the arctic have a far reaching effect on the rest of the planet.
The INCATPA project uses eight air monitoring stations in the Arctic, circumventing the North Pole, and Hung said it is hoped they will create a legacy for the next generation of polar scientists. There are also stations in Dyea and on the Chilkoot Trail which will help to monitor overall effects of airborne pollutants and provide some data on just what is in the air locally. Hung said the NPS has offered a lot of help setting up monitoring stations within the United States, and more than 60 countries are involved.
Data from the first year of the project presented a surprise to scientists. While it was expected contaminates would be evenly distributed into the arctic year-round, there were large spikes in mercury levels during the spring. Hung said this was attributed to the grass-hopping effect, whereby weather conditions and air currents during the spring caused the rapid travel of contaminates from the south, and even so far as China.
These spikes in contaminate levels cause large amounts of pollutants to fall to the ground in a short period of time and poses an immediate threat to the food chain.
Hung explained how the effects of pesticides and coal emissions from distant regions will be felt locally and in the arctic almost immediately. She said spikes in measurements taken from the Tagish, Yukon station were the result of emissions from China only five days earlier.
A computer model of emission flows shown by Hung was particularly disturbing. The motion video showed the progress of mercury emissions in the northern hemisphere over a year-long period. Large red plumes emanating from China appeared to creep their way into Alaska like smoke exhaled from a cigarette.
Hung relayed some good news by indicating levels of certain pollutants are going down, but as China and other developing nations continue to grow certain problems will continue. Endosulfin has been banned by most countries but is still in use as an orchard pesticide in developing countries. Hung said the high levels of the substance in the arctic are not in decline.
As the study continues, more elegant models will create a better understanding of how contaminates are distributed over a wider range, and hopefully will lead to more restrictions when human and animal health is at risk.