Effects of Air Pollutants on Lichens of the Idaho National Engineering Laboratory National Environmental Research Park
Abstract
The Idaho National Engineering and Environmental Laboratory is a (2300 square km) National Environmental Research Park that has been used for research and operational support of nuclear power. The Park includes scattered industrial operations and provides an ideal setting to study effects of industry on semi-arid environments. One of the facilities on the Research Park is the Idaho Nuclear Technology Center (INTEC). This facility reprocessed spent nuclear fuel from the US Navy, and its operations included heating acidic solutions to convert wastes to a solid form. The conversion released nitrogen oxides, low levels of other gases (including HF), and small amounts of solid particles through a facility stack. A fossil-fuel power plant also contributed airborne contaminants including sulfur dioxide. A 1985 study identified the effects of INTEC operations on the health of lichens Xanthoria polycarpa (quantified using electrolyte leakage), on levels of trace metals in the lichens X. polycarpa and Rhizoplaca melanophthalma, and on the levels of trace metals in higher plants and soils. The study concluded that operations impacted the physiological health of X. polycarpa southwest of the plant, and that lead was significantly higher downwind of the plant relative to other locations. Effects of the plant were re-examined in 1999 as part of an Environmental Impact Statement to evaluate the environmental effects of measures available to deal with radioactive waste at INTEC. Sulfur dioxide emissions from the facility decreased from approximately 375 tonsyear to approximately 10 tonsyear between the two studies. The re-examination of lichens showed that the measure of physiological health used in the previous study (conductivity of rinsates collected from lichen thalli) correlated well to the levels of potassium measured in rinsates collected from thalli. There, however, was no correlation between the levels of potassium/conductivity of such rinsates and the levels of total potassium in lichens or between levels of potassium/conductivity and macroscopic vigor of the lichens or between levels of potassium/conductivity in rinsates and chlorophyll ratios (another common indicator of the physiological health of lichens). This suggests that potassium levels in rinsates may not be a good indicator of physiological stress. X. polycarpa abundance varied with direction from the facility. The species was lacking from background locations at Craters of the Moon National monument. Cover on dead Artemisia tridentata twigs varied between 2 and 5% downwind and crosswind for the predominant wind direction, but approached 75% to the north and northeast (downwind) of the facility. This differential cover is striking but was not noted in the previous study and probably reflects increased abundance of the nitrogen loving X. polycarpa downwind from the facility between the two studies. Calcium levels in R. melanophthalma around INTEC were significantly higher than calcium levels in lichens from the background location at Craters of the Moon. This may reflect migration of the species to more buffered calcium carbonate substrates in response to acidified precipitation. Levels of calcium in R. melanophthalma fell between the two studies, possibly reflecting less substrate acidification during the later period. Lead was not significantly elevated during the second study, but mercury may be elevated downwind of the facility.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2001
- Bibcode:
- 2001AGUFM.B32B0115M
- Keywords:
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- 0345 Pollution: urban and regional (0305);
- 1099 General or miscellaneous