Central purchasing program for drugs.

Water samples were collected from the mouths of the three major agricultural watersheds, the Grand, the Saugeen, and the Thames (Ontario, Canada), between January 1986 and December 1990. Analyses were performed for 18 herbicides, 26 insecticides, and 4 fungicides in use in the basins. A total of between 425 and 474 samples were analyzed for each of the major groups of pesticides. Six herbicides, two insecticides and polychlorinated biphenyls (PCBs) were identified in surface water. Atrazine and its metabolite desethylatrazine were the most frequently found pesticide present in 340 of 474 samples or 72%; the metabolite was not always present with the parent compound. The second most frequently found pesticide was metolachlor which was identified in 30 of 474 samples or 6.3%. 2,4-D and cyanazine were present in 3.3% and 1.5% of the samples, respectively; alachlor, mecoprop, and simazine were present in 0.5% of the samples. Dicamba and metribuzin were present in single samples (0.2%). DDT, heptachlor epoxide, and PCB were identified in only single samples over the 5-year period. Between 342 and 2959 kg/annum of total atrazine were found passing the mouth of the three rivers and entering Lakes Erie or St. Clair between 1986 and 1990. The greatest loss was from the Thames River and the least from the Saugeen River. Between 1% and 2% of that applied in the watershed was lost at the mouth. Loadings of only two other pesticides to the rivers exceeded 5 kg in any one year, namely, metolachlor and 2,4-D. In the case of metolachlor, loadings ranged from less than 5 to 1,726 kg/annum, the highest being in the Thames and the lowest in the Saugeen River. 2,4-D exceeded a loading of 5 kg/annum in 1988 in the Grand River. Atrazine, cyanazine, and metolachlor were tracked across Lake St. Clair from the mouth of the Thames to the mouth of the Detroit River in 1987.

Ontario↗

PubMed1990

Teaching physicians about teaching: an experiential workshop.

Teaching improvement workshops are most effective when they engage teachers actively in practice teaching, particularly when the teaching situation is similar to the actual one to which the teachers will return. Teachers, however, often find such involvement threatening. In this paper we describe a 3 h workshop which succeeds in overcoming teachers' reluctance to participate in situations that are relevant to their real teaching problems, students, and subject matter. The most exciting outcome, in our view, was teachers' increased sensitivity to the limitations of their teaching approach and their increased awareness of the role of their concept of teaching in shaping their teaching strategies. Weaknesses of the workshop include its dependence on the skills of a group director, the tendency of the group to seek a single right answer instead of exploring alternatives and the usual danger of role rigidity which troubles all role enactment procedures.

Ontario↗