The instrument has a spectral response function similar to the
action spectrum for erythema in Fig.
Relative spectral response (Dichter et al, 1993) of the instrument is close to Erythemal
action spectrum (McKinley and Diffey, 1987).
The ASCFs account for the differences between wavelength contributions estimated by the erythemal
action spectrum and the previtamin D
action spectrum toward previ-tamin [D.sub.3] production.
The erythemal UV-B spectral range closely mimics the McKinley/ Diffey Erythemal
Action Spectrum.20 Logged readings are converted into hourly MED (minimal erythemal dose) values (1 MED = 210 [Jm.sup.-2] or 583 [Wm.sup.-2]).
This peak wavelength corresponds to the peak of photosynthetic
action spectrum of plants (McCree, 1972).
Typically, for 50 to 75% of the hours of operation the BioLume[TM] will be operating within the amber part of the spectrum at a greatly reduced intensity, away from the critical
action spectrum in terms of hormonal response for humans and other mammals, reptiles, and birds.
The erythemal (sunburn) response of humans to UV radiation is given by the erythemal
action spectrum (Figure 1).
Action spectrum for melatonin regulation in humans: evidence for a novel circadian photoreceptor.
Given that "the
action spectrum of pre vitamin D photosynthesis and that of squamous cell carcinoma are similar, one should expect to find a vitamin D gradient," they wrote.
And even if they do, the
action spectrum of their photodermatitis is in many cases much too broad and patients are too sun sensitive for even broad-spectrum sunscreens to have any effect," Dr.
(5,6) Taking into account the solar spectrum and the
action spectrum of the skin (erythema curve) yields the weighted UV radiation penetration or the UV protection factor (UPF).
In addition, large errors can occur due to out-of-band, non-linear, and non-ideal geometric or spatial response of the UV meters, Finally, in many applications, how well the response of the UV meter approximates the presumed
action spectrum needs to be understood for optimal use of the meters.
In general, a substance is responsible for an observed chemical process when the
action spectrum matches the absorption spectrum.
The threshold data for the acute effects of erythema and photokeratitis were combined on one graph, and an envelope (or hazard) curve was drawn around the collective data so that a single-envelope
action spectrum could be applied to both skin and eye exposure (25) [ILLUSTRATION FOR FIGURE 2 OMITTED].
Even so, the
action spectrum used in my program should be valid for exploring all the reactions of UV light with human skin.