Are pulp and paper mills sources of toxaphene to Lake Superior and Northern Lake Michigan?

Toxaphene was a broad-spectrum pesticide consisting. of a mixture of highly chlorinated bornanes and bornenes. After its ban in 1982, toxaphene concen trations have shown a general decline in the environment as a whole and in most of the Great Lakes specifically. Recent work, however, shows that toxa phene concentrations are not decreasing in fishes from Lake Superior and no rthern Lake Michigan. Non-atmospheric, relatively localized sources are 4 p ossible explanation for these observations. For example, toxaphene could be inadvertently produced and released by pulp and paper mills, which could b e synthesizing toxaphene-like compounds as a byproduct of bleached paper pr oduction. Reported here is a study of surficial river sediment collected up stream and downstream from seven pulp and paper mills, from five areas of p revious toxaphene use, and from two presumed pristine locations. Concentrat ions of toxophene found downstream are similar to those found upstream from each of the pulp and paper mills. Concentrations in sediment from rivers n ear previous toxaphene use locations were higher than concentrations in the background samples. These data suggest that pulp and paper mills are not n ow sources of toxaphene but that toxaphene used as a pesticide in the Great Lakes basin (although these uses were very small compared to its use in th e southern US) could be a potential source.