Motives and Dinitrochlorobenzene

To the Editor.—  In the March 1985 Archives, Happle's editorial¹ did not accurately present our position on dinitrochlorobenzene (DNCB). First, Happle has us arguing that mutagenicity is not due to DNCB but to its "contaminants." What we in fact stated was that "further mutagenic and carcinogenic studies using highly purified DNCB (which is presently unavailable) are necessary."² In the second article, we pointed out that such highly purified preparations of DNCB are not currently available.³ Finally, we pointed out that "whether DNCB is inherently mutagenic or if mutagenicity is due to contaminants remains to be determined" a full ten months before the appearance of Happle's editorial.In fact, our position was more accurately assessed by Dunagin,⁴ who felt our views were too alarmist and who pointed out that "the ratio of therapeutic doses to carcinogenic doses (for a variety of drugs in use by physicians today)