Statistically then, the risk is approximately 1 in 1,000, which is substantially higher than in the normal population. We're also careful to say we do not know what the risk is for individuals with long-term use of the drug.

We had to assess who else might be at risk.

This is a major operation in a high-risk population.

The risk to the general population is very low.

We have, after all, an ageing population, and dementia is generally a condition of ageing, in that the risk increases with age.

Recent information and further analysis leads our agency to conclude that the Southern Resident killer whale population is at risk of extinction, and should be listed as endangered. By giving it protection under the ESA, we have a better chance of keeping this population alive for future generations.