Environmental Chemistry Tip Sheet - January 1998

EMBARGOED FOR RELEASE: Mon., Dec. 29 For further information, contact:

Jim Bohning, 202/872-6041

[email protected]

ENVIRONMENTAL CHEMISTRY TIP SHEET

The following research articles will appear in the January 1st issue of Environmental Science & Technology, a monthly peer-reviewed journal published by the American Chemical Society, the world's largest scientific society.

PURE AS THE DRIVEN SNOW? TRACKING POLLUTANTS ON SNOWFLAKES Snowflakes, like rain drops, can act as scavengers for certain atmospheric pollutants. So falling snowflakes may be esthetically pleasing, but the eye cannot see what might be sticking to the snowflake's surface. Rather than dissolve in the frozen water crystals, some organic gases, such as hydrocarbons, adhere to the surface of the snowflake. This means the amount of material "washed" from the atmosphere in a snowstorm depends on the surface area of the snow. In a study led by the University of Waterloo in Waterloo, Ontario, Canada, a new and reliable method has been developed for measuring the surface area of snow. This information is necessary to determine the fate of these organic gases in snow melt water and glacial ice.

GETTING THE LEAD OUT MAY MEAN CLEANING UP THE OUTDOORS Elevated levels of lead in house dust in urban environments are strongly associated with lead poisoning in preschool children. But in the house dust obtained from carpets in 64 Jersey City, N.J., homes of children at risk for lead exposure, two-thirds of the lead came from external sources and only one-third came from interior lead-based paint, according to a study led by the Environmental and Occupational Health Sciences Institute in Piscataway, N.J. Outdoor sources include both aerosol deposition and tracked-in soils and street dusts. The lead contribution from air is related to outdoor activities that resuspend crustal lead deposits as well as industrial and mobile sources. It may also reflect human activities that resuspend dust indoors, such as vacuuming or sweeping. To effectively reduce lead exposure in urban preschool children, it will be necessary to control both exterior and interior sources, the researchers say..

WHAT IS THE SOURCE OF ATMOSPHERIC MERCURY CONTAMINATION IN REMOTE AREAS? Is Mother Nature to blame, or is it human activity that has spread mercury to the farthest regions of the world? Despite uncertainties in current understanding, there is broad and geochemically consistent data indicating that, over large and remote regions of the globe, human-related mercury emissions have increased relative to natural sources since the onset of the industrial period. This is the conclusion of a new study by scientists at the Universities of Connecticut, Maryland, Minnesota, and the Science Museum of Minnesota. It was issued in response to the work of other researchers who claim that natural geologic sources are the principal contributors of mercury in remote locations. Citing new advances in the analytical techniques used to measure trace amounts of environmental mercury, the report emphasizes that the human-related emissions are significant. However, it is still not possible to quantitatively relate anthropogenic mercury deposition in remote regions to ! the potential exposure to humans and wildlife without additional research.

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