Theme Summary
The Ingesteds theme addresses the exposure of humans to metals via dust, soils, and food. The research will focus on the potential for Canadians to be exposed to metals through diet and inhalation, i.e. food and ingested non-food particles (e.g., soil, house-dust, paint particles). As most Canadians are not occupationally exposed to metals, ingestion constitutes the exposure route of greatest importance. Understanding the relative roles of soils, dust, and food in this exposure is a very important aspect of risk assessment. Without this information, the most effective risk management options cannot be recommended.
The projects under the Ingesteds theme are linked to international efforts to estimate bioavailable fractions of ingested metals; BioAvailability Research Group of Europe’s (BARGE) efforts towards this goal are focused on soil, and the Ingesteds work is linked to BARGE through the participation of Ollson in both teams. Research from this theme will also contribute to the current risk assessments ongoing in several communities in Canada. Metals and metalloids being measured under this theme’s research are: Fe, Ni, Cu, Zn, Mn, Co, Pb, Cd, As, Co, Hg, Tl, and V.
The Foods & Ingested Particles theme contributions to the E & HHRA framework are:
I1: To investigate concerns about poor air quality in the Windsor-Detroit region which have led to a number of health effects studies being conducted by Health Canada on air quality. This study was undertaken to support the Border Air Quality Strategy, an international agreement between the governments of Canada and the US.
I2: Produce results to help guide policy-makers to make decisions about land use, public access, and future risk assessments regarding regulations pertaining to exposure by humans, including children, to arsenic levels in tailings-associated soil that exceed soil guidelines.
I3: Produce findings to allow a better estimation of metal toxicity to the lungs following long term exposure to low metal levels, i.e., a better knowledge of subtle chronic toxic effects that may affect optimal lung function without necessarily producing gross toxicity.
I4: Generate knowledge regarding the bioaccessibility of metals which will allow regulators to set more accurate food consumption guidelines that minimize risk to human communities. By learning of potential differences in metal exposure between foodstuffs, people may limit intake of the most hazardous types of foods.
I5: Generate findings to confirm or refute the suitability of 100% as the default assumption for bioavailability of ingested metals. This default value often results in soil ingestion being the driver for risk assessment. If soil ingestion is not the source of greatest importance, once absorption is taken into account, then there is a chance that the remediation strategy will not reduce risk, which could result in high costs borne by society as well as the party undertaking the cleanup.
I6: Provide input on how much and what type of arsenic Canadians are ingesting from common food items. This information will help reduce the main sources of exposure to toxic arsenic species, thereby protecting public health.
I7: Provide information on characterizing the impact of exposure to metals/metalloids on mutagenesis and highlight sources and pathways of exposure to metals that may be targets for preventive action.
Theme leaders are: Beverley Hale (University of Guelph) and Robert Garrett (GSC-NRCan). Research summaries and researcher contact information for the seven projects under this theme may be viewed here.
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