Metabolites of the pesticide DDT remain in our fatty tissue for years. In the recent New York University Women's Health Study of hormones, diet, and cancer, the blood serum of 14,290 women was stored in order to research blood factors in those who developed cancer compared with those who did not.* Fifty-eight women developed cancer one to six months after entering the study. Careful analysis for DDE (the major metabolite of DDT) was made of their blood and of that of "171 matched control subjects from the same study population, who did not develop cancer." When blood levels of each cancer patient were compared with those of her matched controls, DDE levels were discovered to be significantly higher in the cancer patients. The actual average difference was 2.7 parts per billion. To us this amount may seem tiny. However, the fat tissue in women's breasts, has levels of organochlorines, such as DDE, about 200 times higher than the levels in blood. More important, this overall average difference of 2.7 parts per billion was statistically significant and well above the accuracy limit for their procedure. In fact, they were able to calculate that the probability of finding this large a difference by chance would be less than four in one hundred.

In further research, consideration was given to many other factors that might be related to cancer. The significance of their results increased the most when they added a particular three, namely, history of breast cancer in one's immediate family (yes or no), "lifetime months of lactation," and no children or "age at first full-term pregnancy." Using these adjustments, the risk of breast cancer was more than four times greater in women with 19.1 parts per billion of DDE in their blood over the risk in women with 2 parts per billion. The calculated probability of an increased risk this large or larger occurring by chance was less than four in a thousand.

Breast cancer has been increasing worldwide. This research gives impetus to more attention being paid to pollution from organic compounds containing chlorine. Interestingly, "diminishing rates of breast cancer in Israel have paralleled a precipitous decline in environmental contamination with DDT and benzene hexachloride."

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*Wolff, Mary S. et al, "Blood Levels of Organochlorine Residues and Risk of Breast Cancer," Journal of the National Cancer Institute, 85(8): 648-52, April 21, 1993.

. . . the risk of breast cancer was more than four times greater in women with [the highest level] of DDE in their blood over the risk in women with [the lowest level.]

Article from NOHA NEWS, Vol. XVIII, No. 3, Summer 1993, page 4.