Mj. Howdeshell et Ra. Hites, HISTORICAL INPUT AND DEGRADATION OF TOXAPHENE IN LAKE-ONTARIO SEDIMENT, Environmental science & technology, 30(1), 1996, pp. 220-224
The historical input of toxaphene to Lake Ontario has been determined.
We analyzed total toxaphene concentrations in eight Lake Ontario sedi
ment cores by electron capture gas chromatographic mass spectrometry a
nd found that toxaphene maximizes in 1973 +/- 6 yr with a horizon date
of 1945 +/- 6 yr. The maximum toxaphene flux to Lake Ontario sediment
was 22 +/- 8 mu g/m(2) yr in about 1973, and the total toxaphene load
in the lake is 10 +/- 3 t. By comparing the toxaphene burdens for the
cores, we conclude that toxaphene is deposited to Lake Ontario sedime
nt from both the Niagara River and from the atmosphere. We also found
that toxaphene is slowly dechlorinated after deposition in Lake Ontari
o sediment.