Gary M. Fellers Fumio Matsumura Jeffrey E. Angermann 2002 <p><span>Pacific tree frog (</span><i>Hyla regilla</i><span>) tadpoles were collected throughout the Sierra Nevada mountain range, California, USA, in 1996 and 1997 and analyzed for the presence of polychlorinated biphenyls (PCBs) and toxaphene. Whole-tadpole Σ PCB levels ranged from 244 ng/g (wet wt) at lower elevations on the western slope to 1.6 ng/g high on the eastern slope, whereas Σ toxaphene levels ranged from 15.6 to 1.5 ng/g. Linear regression of PCB and toxaphene residue levels versus elevation indicated a significant relationship, with an </span><i>r</i>²<span> value of 0.33 for PCB and 0.45 for toxaphene indicating a significant elevation effect on PCB and toxaphene bioaccumulation in Sierra Nevada </span><i>H. regilla.</i><span> Tadpole samples from sites in east-facing versus west-facing drainage basins showed significant differences in PCB and toxaphene residue levels, suggesting the possibility of a rain-shadow effect in the long-range atmospheric transport of these contaminants to the Sierra Nevada Mountains.</span></p> application/pdf 10.1002/etc.5620211027 en Wiley Polychlorinated biphenyls and toxaphene in Pacific tree frog tadpoles (<i>Hyla regilla</i>) from the California Sierra Nevada, USA article