In response to your question about extrapolating or doing a cumulative assessment on interactions with other chemicals, and so on, this is certainly why we sometimes need to talk to our colleagues in the agency. It's a field that is very complicated.
But one other thing we do, in part of the assessment, is look at the metabolism, the behaviour of the chemical in our bodies. For example, it's one of the approaches we take for all the organophosphates, when we know their activities and the behaviour is similar. In that case, it would allow us to do the cumulative exposure assessment.
When doing the human risk assessment for residues, we look at the total diet. For example, it means we look at somebody ingesting a tomato that may contain a certain minimal level of residues, versus lettuce that contains other residues, and so on. When we do the overall assessment, we take all that into consideration on the total diet. It's how we look at the various potential interactions or the cumulation of the various chemicals, and so on.
I must say the science, at this point in time, is to look at the total complex mixture. I always look at my stomach as a chemical reactor. It is very difficult to identify every one of those things to see how it behaves.
In the pre-assessment, we look at the individual, and we look at the mechanisms or the action of activities in the body to figure out how it will behave. We then take that into consideration when we do the risk assessment.