This paper compares predictions of environmental fate and effect parameters derived from quantitative structure-activity relationships (QSAR) using estimates of molecular total surface area (TSA) with experimental data. Organotins are used as an example. In addition, a simple linear free-energy relationship with TSA is demonstrated to be applicable to organotin aqueous solubility, chromatographic retentivity, octanol-water partition coefficients and bacterial uptake, and aquatic toxicity. New measurement methodology providing nondestructive optical imaging in vivo of tin employing a fluorescent, tin-specific ligand (3-hydroxyflavone) is used to evaluate a likely mechanism of uptake for triorganotins on cells. Finally, the laboratory results are extended to a preliminary appraisal of environmental persistence of tributyltin, which involves both uptake and degradation processes.