FIG. 1.
Biological hormetic dose/response of H2S exposure. H2S, shown in molecular form with one yellow circle (sulfur) and two smaller circles (hydrogen), displays a multiphasic dose/response. Adverse effects and conditions (shown in red) arise from too little or too much H2S exposure. Beneficial effects (shown in green) occur at specific H2S exposure and/or production capacity levels. The potential exists for both negative and positive responses to occur simultaneously at either end of the beneficial H2S exposure range; H2S, hydrogen sulfide. To see this illustration in color, the reader is referred to the web version of this article at www.liebertpub.com/ars