Good afternoon. I'm Dr. Roger Keefe of Imperial Oil. I was asked to speak to you on today's topic by the Canadian Chemical Producers Association. I also work closely with the industry coordinating group for CEPA; they have also previously appeared before you.
My views are technical in nature. They're based on about 30 years of experience since I completed my PhD and somewhat less since I got board certification in toxicology. Most of those years were in industry, dealing with safety testing and risk assessment. My career has focused on mammalian toxicology and human health risk assessment, and that's going to be the focus of most of what I say.
My remarks are really in support of just two basic propositions. One is that the susceptible subpopulations in ecosystems are already considered in risk management decisions made under CEPA when there is scientific evidence. Number two is that while consideration of susceptible subpopulations in ecosystems is implicit, there may be good reason for not making it more explicit in CEPA. I'll elaborate on those two.
On the first, that consideration is already given to susceptible subpopulations, it is clearly demonstrated in the existing CEPA risk assessments. For example, under the priority substances list program, human exposures during different life stages are estimated, and risk assessment conclusions were based on the most-exposed life stage, whether it was infants, children, adults, or the elderly.
Although less common, if there was a known difference in susceptibility owing to gender or race or any other factor, the guidance value or exposure limit that comes out of the risk assessment would be based on the most vulnerable group. This is standard procedure in toxicology when there is documented sensitivity for a substance.
There are other procedures at Environment Canada and Health Canada that should give us assurance that sensitive subpopulations in ecosystems are being considered. I just have four bullets here. First is their participation in international assessments and tool developments such as the World Health Organization, mentioned earlier, or the Organisation for Economic Co-operation and Development. Most substances, after all, are not unique to Canada in today's global market.
The second is the use of outside academic experts for advice and peer review of assessments. I think that keeps the departments at the cutting edge of science in doing a good job and in being aware of any evidence on susceptibility.
Third is the use of staff with skills and experience to conduct risk assessments--people who in academia are referred to as high-quality personnel.
Fourth is the maintenance of the capacity to conduct and publish peer-reviewed research.
It should not surprise you, given my background, that these four points are in recognition and support of a high-quality scientific risk assessment process in general. When that process is well informed and well executed, the current risk assessment process takes into account sensitive subpopulations in ecosystems.
My second proposition--that it may be better to leave consideration of susceptible subpopulations in ecosystems implicit in CEPA--stems from the need for professional judgment to deal with a lack of the necessary scientific information. Absent data on vulnerability, it would be better to use professional judgment on a substance-by-substance basis to choose between precaution and more research.
If vulnerable subgroups are explicitly considered in the act, it will likely lead to greater precaution, because data are often lacking. I would prefer to fill data gaps to reduce the uncertainty in the decision-making process rather than build into the act an allowance for greater uncertainty with unknown risk benefits. We need decisions that are based on better knowledge.
A concern I have about a broad increase in the use of precaution is that decisions may not be reviewed, at least for a long time, in light of new data. A principle in the Government of Canada's paper on the use of precaution in decision-making is a reconsideration of precautionary measures. If more decisions are going to be precautionary in nature, then we will need to reinforce this principle and ensure that substance risk assessments are reopened as new data become available.
Professional judgment by the government side will continue to be aided by the ongoing research on susceptible subpopulations in ecosystems. Currently there are a wide variety of genetically modified knock-out mice, for instance, that could be used as models of the heterogeneity in the human population. Gene arrays containing dozens or even hundreds of genes are also being used to study how genes are up-regulated or down-regulated in response to substances. Developing research on epigenetics and the use of bio-monitoring in risk assessment will also affect the way we assess susceptible subpopulations. These are very active areas of research now, and we need to have the flexibility to incorporate new results or tests into our risk-based approach.
Finally, what tests and how much testing there ought to be should depend on how a substance will be used and who may be exposed. So it should be decided on a substance-by-substance basis; it's impractical to test all species or potentially exposed subgroups. Increased testing, or costs, could be a barrier to use of a substance in Canada or may limit its uses here since Canada is such a small market. Those potential economic losses, or the loss of other benefits of the substance, need to be balanced against the unknown reductions in risk. Other likely costs to consider are larger government departments to conduct or interpret test results, and a possible burden on industry as well.
In summary, if scientific information is available, I believe it is being used and will continue to be used to account for susceptible subpopulations in ecosystems. Where such information may not be available, I believe the exercise of professional judgment implicit in CEPA, given the range of powers already in the act, is adequate to account for susceptible subpopulations in ecosystems.
Thanks for inviting me to appear.