Donald R. Bennett, M.D., Ph.D      Pages 415-518
Vol.2, July 19, 1994

 

In regards:  Silicone Breast Implants

MDL926

 

Page 415

 

1                    And my question was whether

2                    There was an effort to look at both

3                     inorganic silicon  as well as organic

4                    silicons in the time period.

5                    THE WITNESS

6                    There would be three classes

7                    of compounds to examine.  One would be

8                    organosilicon compounds.  The second group

9                    would be organic silicates in which

10                There’s no carbon directly attached to

11                silicon.  And the third group would be

12                inorganic silicon in which there are no

13                organic moieties present in the molecule

14                At all.

15                We spent most of our time

16                studying organosilicon compounds.  We did

17                very little with organic silicates like

18                silicic acid and those sorts of materials

19                We did very little with inorganic silicon,

20                which was principally silica and various

21                Mineral dust and things of that sort.  The

22                only reason we had some interest in

23                organic silicon was that Carlisle and

24                another person—and I can’t remember at the

25                moment--had determined that silicon

 

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1                    might very well be an essential element

2                    in the chick and chicken and in the rat.

3                    And so, therefore, at times we

4                    would plan to do studies looking for what

5                    that natural silicon product might be in

6                    bone cartilage, connective tissue, but we

7                    didn’t really ever have the luxury of

8                    doing what we would have liked to have

9                    done with it.

10                So that’s a long answer, but

11                you need to understand that we—we just

12                didn’t get around the silica as such or

13                other molecules like it.

14                EXAMINATION BY MR. ELLIS

15                Q.        Okay.  Now, talking about

16                silica, that’s SiO2 or silicon dioxide—

17                A.        Right

18                Q.        --did you do any type of

19                literature searches to see if various

20                forms of silica did possess some

21                biological activity?

22                A.        I not only kept a fairly large

23                file on it which I turned over to you—

24                That was the major reason why I did not

25                get rid of my reprints, because after I

 

Page 417

 

1                    left the corporation rather that just

2                    throw them away.  I—thought I might be

3                    writing a chapter on silicon, and it was

4                    going to be oriented principally towards

5                    inorganic silicon and silica and silicic

6                    acid.  So I kept a fair  number of reprints

7                    in my file which we did not utilize in our

8                    everyday work at Dow Corning but which I

9                    utilized to write that chapter and then

10                published it in 1978.

11                Q.        Okay.  And what book was that

12                published in?

13                A.        It was published in the

14                C.R.C. Handbook.  It’s in my bibliography.

15                It was a chapter on silicon as a—as a

16                nutrient.  It should be right there.  I

17                can find it quickly for you.

18                Q.        Effective Nutrient Toxicities

19                in Animals and Man, Silicon, pages 347-348

20                in the C.R.C. Handbook?

21                A.        Right.  So it was principally

22                A literature survey.

23                I had approximately—I don’t

24                know how many reprints there were in those

25                two boxes, but I utilized a hundred and

 

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1                    six references, I believe, which is about

2                    par for the course.  It’s about ten

3                    percent of what you collect and sometimes

4                    that you lose.  And it was principally

5                    devoted to toxicity associated with the

6                    kidney and toxicity associated with the

7                    lung, which is where you’d expect to find

8                    silica.

9                    Q.        And, in fact, you were

10                familiar in the late 60’s with the

11                condition called silicosis; correct?

12                A.        Yes.

13                Q.        And you had looked back at the

14                literature on both crystalline silica and

15                amorphous silica?

16                A.        Right.

17                Q.        And you looked for articles

18                which discussed the toxicity of each of

19                those types of silicas; correct?

20                A.        Right.

21                Q.        And you were aware that

22                Silica—or at least the fumed silica or

23                Amorphous silica—was used in a variety

24                Of the medical products as a filler for—

25                MR. DONLEY