In order to assess the lifetime risk of skin cancer for recreational users from dermal exposure to polycyclic aromatic hydrocarbons (PAHs), sediment samples were collected from beach sites along the St. Marys River near Sault Ste. Marie, Ontario, and in Hamilton Harbor and Toronto Harbor, Ontario, and analyzed for PAHs. Dermal exposure and lifetime skin cancer risk were estimated as follows: Concentrations of 11 PAHs with sufficient or limited evidence of carcinogenicity or mutagenicity were converted to benzo(a)pyrene (BaP) equivalents using toxic equivalency factors (TEFs). Lifetime dermal exposure values were derived based on the BaP equivalents in the silt + clay fraction taken as representative of suspended sediment particulates to which recreational users would be exposed. The lifetime health risk of skin cancer associated with such exposures was above the negligible risk level of 1.0 x 10(-6) at offshore Rytac, Lake George Channel, and Bell Point beaches in the St. Marys River; at Pier 4 Park in Hamilton Harbor; and at Humber Bay, Sunnyside Beach, Cherry Beach, and Water Rats Sailing Club in Toronto Harbor. Risk was negligible inshore at the Rytac and Bell Point beaches and at Squirrel Island and Ojibway Trailer Park along St. Marys River, at Lax Beach in Hamilton Harbor; and at Centre Island in Toronto Harbor. Strategies to reduce risk were developed with these communities; a key recommendation was to take a bath or shower within 24 h after a swim because virtually all the PAHs on the skin would be removed.

One of the most significant weaknesses in modern day water quality management is the detection of microbiological indicators. Microbial tests are normally conducted off-site, often resulting in long turn-around time, risk of contamination, cross contamination and adulteration. Here Stephen Brown and Moe Hussain present a thought provoking case study where limitations in current analytical technologies for water monitoring had fatal results and discuss new approaches to microbiological monitoring that might prevent similar disasters occurring in the future.

Six prairie grain farmers were monitored for pesticide exposure and related adverse effects while they mixed and/or sprayed carbofuran (Furadan 480F) with ground rig application equipment to control grasshoppers in southern Alberta, Canada. Dermal exposure was estimated with Tegaderm patches placed at seventeen locations on the skin beneath the work clothes. Hand and wrist exposure was determined by the amount of chemical found in hand rinses and on wrist patches. Potential inhalation exposure was measured with an air sampler using polyurethane foam as the adsorbent. Urine samples were collected at 24-hr intervals after exposure and monitored for carbofuran. Blood samples were analyzed for acetylcholinesterase (AChE), pseudocholinesterase (ChE) and several other blood parameters. The results indicated that during the mixing and/or spraying operation, a farmer could potentially be exposed to a total of 1,264 micrograms carbofuran per kg of active ingredient (a.i.) used. Of this amount, 1,262 micrograms/kg (or 99.8%) was dermal and 2 micrograms/kg (or 0.2%) could be through the inhalation route. Hand and wrist exposure was about 1,100 micrograms/kg a.i. (or 87% of total exposure). Excretion of the chemical in the urine amounted to 28 micrograms/kg a.i. No ChE inhibition was observed. Other blood measurements were within normal ranges. The farmers showed no acute adverse effects during exposure and for four days after exposure. These results are discussed in relation to the mammalian toxicity of carbofuran.

Health Canada sponsored a workshop on March 1-3, 1994, in Aylmer, Québec. The objectives of the workshop were to present the research findings of the department's five-year Great Lakes Health Effects program, to identify key conclusions from the research, and to define future research priorities. About one hundred researchers from various disciplines such as monitoring, exposure, general toxicology, carcinogenesis, mutagenesis, reproduction, teratology, neurotoxicology, immunotoxicology, risk perception, and environmental sociology participated in the workshop. Future objectives, to be achieved by the year 2000, were recommended by the participants for the second phase of the Great Lakes program. These included: obtaining additional monitoring data on fish, wildlife, wild birds' eggs, water, and sediment for the "critical" contaminants in the Great Lakes; establishing a human tissue bank to assess trends in the levels of such contaminants in humans; using models to assess human exposure to these contaminants from various biota; identifying groups that are highly exposed to the chemicals in the Great Lakes; identifying individuals who are overly sensitive to chemicals in the Great Lakes; increasing research on the influence of environmental contaminants on male fertility; continuing work on mixtures of the critical contaminants as well as on individual contaminants, and increasing research on the changes in public perception, values, attitudes, and behavior as a consequence of environmental pollution.