USE AND EVALUATION OF BIOLOGICAL SPECTRAL UV WEIGHTING FUNCTIONS FOR THE OZONE REDUCTION ISSUE - Environmental UV Radiation: Impact on Ecosystems and Human Health and Predictive Models - page 79

Rousseaux et al. [34] took advantage of changes in solar spectral irradiance as
the Antarctic vortex containing ozone depleted air, the so-called "ozone hole'', passed
over Tierra del Fuego at the southern tip of South America to test different BSWF. They
measured DNA damage in the form of cyclobutane pyrimidine dimers extracted from
intact leaves in the field following half-day exposures to solar radiation. In this manner
they tested how well solar spectral irradiance weighted with five different BSWF
predicted DNA damage under these conditions. The BSWF that declined more steeply
with increasing wavelength (and therefore resulted in greater RAF values) generally had
the better fit with these data (Figure 7). This was not entirely expected since the one
BSWF tested with the smallest RAF of the group had the poorest fit and yet was based
on an action spectrum for DNA damage in intact plant seedlings (Figure 7).
3. Conclusion
The use of BSWF in assessing the ozone reduction issue is clearly highly important.
Even small differences among BSWF can have large consequences when employed in
various predictions of RAF values, latitudinal gradients and in experimental design
involving lamp systems. It is unlikely that the same BSWF will be appropriate for all
responses to UV radiation. Thus, realistic testing of these BSWF under polychromatic
radiation, especially under field conditions, is critical.
Acknowledgements
This work derives in part from financial support from the United States Department of
Agriculture (CSRS/NRICG grants 95-37100-1612 and 98-35100-6107) and the
NSF/DOE/NASA/USDA/EPA/NOAA Interagency Program on Terrestrial Ecology and
Global Change (TECO) grants (95-24144 and 98-14357) from the US National Science
Foundation.
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