Deeper Insight

I read “Measuring Persistence” with great interest (C&EN, March 2, page 10). However, I do recall slightly different versions of the two events mentioned in the article: the PCB (polychlorinated biphenyl) poisoning in Michigan and the Kepone poisoning in Virginia. The Michigan Chemical Co. manufactured Nutrimaster, a lactating agent, and Firemaster, a flame retardant. The Firemaster bags had been depleted, and the Nutrimaster bags were used by mistake.

As for the incident in Hopewell, Va., Allied Chemical was no longer manufacturing Kepone because of a lack of profit and so allowed some of its workers to continue the process in a defunct service station. The process was not performed under ideal conditions, brought to light by the fact that the men working in the plant were all young, married, and childless. An internist determined that they were not producing sufficient sperm; exposure to Kepone was suspected as the reason. There may have been other symptoms, as the article reports, but this is the driving force that I remember.

Virlyn W. Burse
Atlanta