1. Dep. of Soil Science; Univ. of Manitoba; Winnipeg MB Canada R3T 2N2
2. Toxicology Centre; Univ. of Saskatchewan; Saskatoon SK Canada S7N 5B3
3. Environment Canada; Saskatoon SK Canada S7N 3H5
4. Agriculture and Agri-Food Canada; 5403 1st Ave. S. Lethbridge AB Canada T1J 4B1.