Day 038 - 19 Oct 94 - Page 45
1 high incidence in the control groups, but I have never seen
2 the comparison explored for historical controls.
3
4 MR. JUSTICE BELL: Can you turn the three per cent or the five
5 per cent into something which is meaningful so far as
6 quantity is concerned? I mean, the five per cent dietary
7 group, what does that mean, that five per cent of their
8 daily diet is actually Sunset Yellow?
9 A. Indeed it is, which is a very -----
10
11 Q. If I had three soft drinks in a day with Sunset Yellow in
12 them, I appreciate they appear in cereals, sauces sources
13 and fish fingers and so on as well, but what percentage of
14 my diet would the Sunset Yellow and three soft drinks
15 contain? Can you give me any idea?
16 A. It is difficult to be precise because even when used in
17 commercial products it is used in dilution, but I would be
18 surprised if it was anything approaching that level. It is
19 likely to be a thousandth of that level or less, would be
20 my guess, of the total diet.
21
22 Q. That is what I had rather assumed. I had assumed that if
23 it was five per cent or three per cent of my daily diet --
24 I mean, is that by weight or volume?
25 A. That is by weight.
26
27 Q. Does that include drink or just -----
28 A. No, that includes -- typically in these feeding studies
29 it would be just the drink. The animals would be at
30 liberty to drink as much fluid as they liked, whereas that
31 would be free of the test compound.
32
33 Q. That is all liquid, is it, their diet?
34 A. It varies from study to study. You will find studies
35 in which they consume all their intake in a liquid form
36 but, more commonly, they take solid food with the additive
37 incorporated into solid food and they take liquid as well.
38 When you estimate the dose that the rats received, it is a
39 rather complex calculation because you have to know how
40 much is present in the food, you have to weigh the amount
41 of food daily before it is given to the rat. You weigh how
42 much is left. You, therefore, calculate how much they
43 should have ingested, and you then have to calculate that
44 as a proportion of the weight that the rat is at that time
45 in order to estimate the dose in milligrams per unit body
46 weight that the rat has had.
47
48 So, while you have a constant dosing level of the food,
49 that does not directly correspond to a constant dosing
50 level of the body weight of the rat. It is calculated as
51 an average over the animal's lifetime.
52
53 Q. Since I have interrupted anyway, the other matter is this,
54 so I can get some idea of what the ADIs mean: Suppose a
55 man weighed about 75 kilograms?
56 A. Yes.
57
58 Q. I think that is about 11 stone 11, he is going to be ADI
59 awarded in 1975 -----
60 A. 2.5 milligrams.
