Action spectroscopy in complex organisms: potentials and pitfalls in predicting the impact of increased environmental...

Evaluating the effects of broad spectrum sources, including sunlight, on humans and their environment requires knowledge both of the effects of various wavelengths of radiation in those sources on biological systems and of the kinds and magnitude of changes in those sources. Action spectroscopy-the determination of the effect of radiation on an organism as a function of wavelength-provides a major method for evaluating the effects of a source, including that of changes in its intensity and wavelength distribution. Although action spectra for UV radiation damage to higher organisms can give useful information, inappropriate analyses can lead to misleading or even incorrect results. It is thus essential to consider carefully methods of analyzing action spectra and their consequences for evaluating the effects of changes in the solar spectrum.