No abstract

A large landfill fire occurred in Iqaluit, Canada in spring/summer 2014. Air quality data were collected to characterize emissions as well as potential threats to public health. Criteria pollutants were monitored (PM2.5, O3, NO2) along with dioxins/furans, polycyclic aromatic hydrocarbons, and volatile organic compounds. Median daily dioxin/furan concentrations were 66-times higher during active burning (0.2 pg/m(3) Toxic Equivalency Quotient (TEQ)) compared to after the fire was extinguished (0.003 pg/m(3) TEQ). Other pollutants changed less dramatically. Our findings suggest that airborne concentrations of potentially harmful substances may be elevated during landfill fires even when criteria air pollutants remain largely unchanged.

No abstract

Under sections 73 and 74 of the revised Canadian Environmental Protection Act (CEPA 1999), Environment Canada and Health Canada must "categorize" and "screen" about 23,000 substances on the Domestic Substances List (DSL) for persistence (P), bioaccumulation (B), and inherently toxic (iT) properties. Since experimental data for P, B and iT are only available for a few DSL substances, a workshop was held to address issues associated with the use of Quantitative Structure-Activity Relationships (QSARs) to categorize these substances. This paper describes the results of an 11-12 November 1999 International Workshop sponsored by Environment Canada to discuss potential uses and limitations of QSARs to categorize DSL substances as either persistent or bioaccumulative and iT to non-human organisms and to recommend future research needed to develop methods for predicting the P, B and iT of difficult-to-model substances.

The ecological risk assessment of commercial chemicals in Canada by the regulatory programs of the Commercial Chemicals Evaluation Branch, Environment Canada, are based on results from traditional toxicity data (e.g., lethality, effects to growth or reproduction). Some of the chemicals under consideration are known to alter endocrine systems in exposed organisms; however, effects to the endocrine system are used only as additional supporting information. Presently, there are no internationally accepted methodologies or tests for endocrine disrupting substances that can be used by these regulatory programs. The need for research with respect to hormone disrupting substances has been recognized in the revised Canadian Environmental Protection Act, 1999 (CEPA 1999). This paper describes the framework for the ecological risk assessment of new and existing substances and identifies issues and research needs in both screening level and in-depth ecological risk assessments with respect to the identification and assessment of potentially endocrine disrupting substances.