Published online 3 June 2009 | Nature 459, 620-621 (2009) | doi:10.1038/459620b
Corrected online: 11 June 2009


Funding struggle for mercury monitoring

Researchers look to quantify pollution levels.

Nicola Pirrone may need all the help he can get next week. In the hallways of a conference in Guiyang, China, Pirrone — the director of Italy's CNR-Institute for Atmospheric Pollution Research — will be trying to rustle up support for a global network to monitor mercury pollution.

Such a network would underlie a United Nations Environment Programme (UNEP) treaty to control mercury emissions, which negotiators plan to forge by 2013. So far, countries from Mexico to South Africa to Japan have expressed interest in setting up a monitoring system. But to turn interest into reality, researchers are facing a complex task on what may be shoestring budgets.

Anthropogenic sources emit about 2,500 tonnes of mercury every year, more than half of which comes from fossil-fuel power plants (see chart). But so far, global monitoring endeavours have been relatively uncoordinated; hundreds of sporadic efforts can include one-time samplings from a ship cruise or aeroplane flight.


The United States and Canada do have networked and standardized stations that can monitor mercury deposition at a high enough precision over the long term to be useful in a treaty. These include sophisticated monitors made by Tekran Instruments Corporation in Knoxville, Tennessee, which can collect mercury from both rainfall and dry air and determine its chemical form.

US researchers have been working to combine data from about a dozen Tekran-equipped sites, along with other longer-term studies, into a national monitoring effort called MercNet that could serve as a starting point for a global network. Some initial high-quality worldwide data are starting to become available, for instance from Changbai Mountain in northeastern China (Q. Wan et al. Environ. Res. 109, 201–206; 2009).

But expanding the number of sites globally will be expensive. A top-of-the-line Tekran monitor costs about US$100,000, not including operational costs. On top of that, mercury researchers would like to see a host of other measurements, including regularly scheduled aeroplane monitoring high in the troposphere to see how chemical reactions change airborne mercury; research cruises to measure what is happening in the ocean–air boundary layer; and more data on mercury levels in the oceans themselves.

One money-saving option might be to piggyback mercury measurements on other sites that already collect atmospheric data, says Robert Mason, an environmental chemist at the University of Connecticut in Groton. Mason is advising researchers who are working to set up a network in China, Japan and Korea, including expanding existing stations.

But some researchers worry that the focus on air monitoring may mean that other parts of the environment get overlooked. "There has to be a biological component to this," says David Evers of the BioDiversity Research Institute in Gorham, Maine. That could mean, for instance, identifying 'hot spots' that receive airborne mercury and turn it into a form that could be taken up by fish and then humans.

Pierrette Blanchard, an atmospheric chemist at Environment Canada, notes that even fish in seemingly pristine lakes in national forests in the United States and Canada can contain high levels of mercury.

In particular, Evers wants to see estuarine and marine sampling in the Amazon basin, where small-scale gold mining releases mercury into environments where fish are caught for food. He and his colleagues have also proposed a marine and estuaries network for monitoring the US Atlantic coast.

And Evers and others have been advising Senator Susan Collins (Republican, Maine) on a bill that would provide funding from the US Environmental Protection Agency for a national mercury network to include air, water, soils and animals. Collins has tried several times before; in 2007, for instance, she requested that $18 million be designated, but the effort died at the committee stage. Collins hopes to reintroduce the bill this summer.


The costs of an international monitoring system are unknown, and will depend on how much various countries are willing to put up for equipment and staffing. That may be a point for discussion when negotiations for the UNEP treaty begin in earnest early next year. The talks have been boosted by the United States, which had long called for voluntary-only mercury monitoring but in February indicated it would support an international regulatory structure. "What we need to do is to inform the negotiations," says a US state department official who requested anonymity because of the talks.

Bettina Hitzfeld, a UNEP negotiator for the Swiss Federal Office for the Environment, says that treaty discussions need to start moving ahead even in the absence of a complete monitoring system. "We cannot afford to wait," she says, "for a mercury network to be up and running." 


There is a "Correction": associated with this article. An earlier version of this story erroneously located Changbai Mountain in Taiwan.
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