Biomonitoring supportive research

Development of biomonitoring equivalents and use of physiologically based pharmacokinetic models for interpreting Canadian biomonitoring data

The ability to quantitatively interpret the results of human biomonitoring in the context of health risk assessment has not kept pace with the analytical capability of measuring chemicals in biological tissues and fluids. Quantitative benchmarks (Biomonitoring Equivalents, or BEs) of acceptable or safe concentrations in biological specimens are needed to interpret these levels for chemicals of interest. This three year project initiated in 2008 is a collaboration amongst Summit Toxicology (developer of the BE concept), Health Canada, and researchers within Canadian universities to use expertise and build capacity to develop BEs within Health Canada and among Canadian universities. Health Canada is developing BEs for several priority chemicals, for both risk assessment and management, and evaluating them for their application in biomonitoring surveillance initiatives.

Toxicokinetic modelling of pyrethroids for dose reconstruction in the Canadian population

Toxicokinetics is the study of how chemicals are absorbed, metabolized, and disposed of in animals or people. Toxicokinetic models can be used to measure the relationship between the chemical by-products (biomarkers) measured in people and the amount of chemical absorbed. In this two year project initiated in 2009, human toxicokinetic models are being developed for two commonly used pyrethroid pesticides, permethrin and cypermethrin. Levels of metabolites from these pesticides are being measured in the Canadian population, to determine the absorbed chemical dose.

Identification of biomarkers of environmental contaminant toxicity through analysis of Maternal-Infant Research on Environmental Chemicals (MIREC) samples

This three year project initiated in 2008 is complementing the goals of the MIREC study, the aim of which is to determine what pregnancy risks, if any, are associated with exposure to heavy metals (lead, mercury, and cadmium). This study is examining the effects of chemical contaminants on fetal development by measuring specific biomarkers related to contaminant exposure.

Dermal absorption of substances being assessed under the Chemicals Management Plan

Skin is a major route of entry to the human body for many substances, especially those in consumer products such as cosmetics. As a result, it is important to understand how chemicals are transported from the outer surface of the skin to internal layers and blood circulation. This is especially important when trying to determine what types of chemicals we are exposed to, and how these may affect human health. This two year project initiated in 2009 is establishing routine test methods to measure the dermal absorption of chemicals that have been identified as having a priority for human health. This will allow for more accurate estimates of exposure levels.

Analytical tools for health and environmental biomonitoring of manufactured nanomaterials in chemical substances and Food and Drugs Act substances

The goal of this three year study initiated in 2008 is to expand our knowledge of some currently manufactured nanomaterials and to determine methods to monitor exposure to them. Analytical methods are being used to characterize the nanomaterials, and methods to monitor exposure to these materials are being analyzed. Preliminary testing is also being performed to examine any potential health or environmental effects. This project will serve as a gateway for more advanced research to characterize the loadings, fate, and exposure pathways for contamination by nanomaterials.

Study of metabolomic and transcriptomic responses with high and low exposures to brominated flame retardants

This three year study initiated in 2008 is examining whether the level of exposure to BDEs is correlated to changes in genetic and biochemical processes essential for normal pregnancy and fetal development. Human tissue is being examined when exposed to various levels of BDEs.