Kronberg Research Conference, 1969

Nine delegates from various affiliated companies, including delegates from England and from Kentucky, attended the 1969 research conference, held in Kronberg, Germany. The draft agenda {1113.01} covers a range of topics similar to those discussed at the Hilton Head conference: (1) reports of ongoing research projects, including Hilton (an inhalation experiment at Battelle), Lokstedt, and Janus (mouse skin painting to test for cancer); (2) discussions of nicotine pharmacology, carbon monoxide, solids in smoke, nontobacco materials, reconstituted tobacco, coumarin, black-fat tobacco, PEI, and "the current safest cigarette"; (3) product development; (4) process R&D, including leaf tobacco developments, freeze-drying, tobacco treatments, additives, reconstituted tobacco, and microbiological flora.

The minutes of the meeting include a lengthy discussion of the biological testing program. A major conclusion of this discussion is expressed as follows:

The conclusion of the Conference was that at the present time the Industry had to recognise the possibility of distinct adverse health reactions to smoke aerosol:

and present and future bioassay tests could usefully be classified according to their applicability to one or other or to both. {1169.01, p. 3}

The careful wording here is in keeping with industry dogma, but the statement is, nonetheless, far more forthright than the Zephyr document of the previous decade. A yet more frank assessment was to appear in the minutes of these meetings in the 1970s (see below). Despite this wording, the relative frankness of the comments on smoking and cancer in these minutes led to a strong letter (discussed in detail in chapter 7) from David Hardy at the law firm of Shook, Hardy, and Bacon to DeBaun Bryant, B&W's general counsel, warning that such admissions could lead to serious liability problems for the company {1840.01}.

Participants also discussed the mouse skin—painting experiments at Harrogate and the relative value of short-term biological tests as compared to mouse skin—painting studies. Cooperative industry studies in

the United Kingdom had revealed important differences in carcinogenic activity between two preparations of tobacco condensate:

This appears to be a significant alteration in mouse-skin bioassay reaction brought about by an alteration in tobacco composition. {1169.01, p. 1}

Unfortunately, though, a difficulty had arisen in specifying the precise compositions of the two condensates, so it was not clear how to replicate the finding or what changes to make in blending to carry this result further. The participants suggested that those in charge of this work should get in touch with the University of Kentucky to explore ways in which conventional strains of tobacco could have such marked differences.

The conferees endorsed fractionation experiments at Harrogate to see what subfractions of condensate act as promoters and initiators of cancer. Mouse skin painting remained the standard for carcinogenesis:

In the foreseeable future, say five years, mouse-skin painting would remain as the ultimate court of appeal on carcinogenic effects. {1169.01, p. 4}

At the same time, short-term biological tests, such as a test of hyperplasia (an abnormal increase in the number of cells), were of interest both for their potential to act as predictors of mouse skin–painting results and as indicators in their own right of important toxicities of tobacco smoke. The conferees agreed, though, that there would be no consensus on what the results of short-term tests meant: any interpretation of short-term bioassay results as predictive of carcinogenic potential was "the responsibility of the user" alone {1169.01, p. 4}. Meanwhile, the tobacco industry's public position was that mouse skin painting is an unreliable way to test whether cigarette smoke causes cancer.