Mercury (Hg) Monitoring in Oklahoma

The Air Quality Division monitors mercury at four sites in Oklahoma as part of the National Atmospheric Deposition Program's (NADP) Mercury Deposition Network (MDN). The NADP is a cooperative monitoring program of federal and state agencies, academic institutions, Native American tribal governments and private organizations. The MDN began measuring total mercury in precipitation (wet deposition) in 1996. The division set up the McGee Creek Lake and Copan sites in 2006 and added the Lake Murray and Wichita Mountain sites in 2007. The MDN currently monitors total mercury at more than 100 sites across the nation.

The Network's objective is to develop a nationwide database of weekly concentrations of total mercury in precipitation, and the seasonal and annual flux of total mercury in wet deposition. The data will be used to identify seasonal trends in mercury deposited to surface waters, forested watersheds and other sensitive receptors. For more information on this program go to: http://nadp.sws.uiuc.edu/mdn .

About Mercury

Mercury is in a class of chemicals called persistent bioaccumulative toxins. It persists in the environment for long periods by cycling back and forth between the air, water, and soil, all the while changing chemical forms. Mercury can become airborne when coal, oil, or wood are burned as fuel or when mercury-containing wastes are incinerated.

Once in the air, mercury can fall to the ground with rain and snow, contaminating soil and bodies of water. When mercury enters bodies of water, bacteria and other processes transform a portion of it to methyl mercury (MeHg) which is highly toxic and accumulates in the tissues of fish. As humans consume fish, they also consume any methyl mercury in the fish. Humans also bio accumulate MeHg if they consume it faster than their bodies can remove it.

By consuming less MeHg-contaminated foods, concentrations in humans should decrease. This is the basis of fish consumption warnings for mercury. Local fish consumption warnings are posted on the DEQ web site at: http://www.deq.state.ok.us/csdnew/fish/index.htm .

Oklahoma's mercury monitoring sites are in the Wichita Mountains, at Lake Murray State Park, at McGee Creek Lake and near Copan. The Cherokee Nation operates a fifth MDN site near Stilwell.

Last updated November 10, 2011