Study of DDT blood level in a group of workers exposed to pesticides.

Blood levels of DDT, DDE, and other DDT metabolites were determined in a group of workers with previous occupational exposure to DDT as spraymen. The larger part of total DDT was in the form of metabolite DDE, which is thought to be introduced into the human body primarily from external sources. Total DDT blood level was correlated positively with both age and occupational exposure (R = 0.58 and 0.52, respectively), and linear regressions between storage and these variables were demonstrated. Although the storage of these compounds in body fat was not studied, the analysis of covariance showed a significant increase of DDT blood level in the group of workers with longer occupational exposure, which was not dependent on age.

Lack of correlation between free erythrocyte porphyrin and serum ferritin values at birth and at 2 months of life in low birthweight infants.

Red cell free erythrocyte porphyrin and serum ferritin determinations were performed on capillary blood specimens from 63 healthy infants weighing 2500 g or less at birth, during the first week of life, and, from 44 of them, again at 8-10 weeks. Free erythrocyte porphyrin values were high both at 3-7 days (mean 156 microgram/100 ml RBC) and at 8-10 weeks (mean 128 microgram/100 ml RBC). The respective serum ferritin values were also high (mean 226 and 107 ng/ml), excluding a depletion in iron stores. In addition, no correlation was found between free erythrocyte porphyrin and serum ferritin values either at birth or at age 2 months. These findings are consistent with an earlier hypothesis that in the presence of iron stores, the rate of iron release from the stores in low birthweight infants may not be sufficient to maintain optimal erythropoiesis if the demand is accelerated.