Tungsten and Cobalt in Fallon, Nevada: Association with Childhood Leukemia

centa was higher in Finnish than in Danish samples (Shen et al. 2007). Country of origin was therefore included as a covariate in a binary logistic regression. We found no significant difference between mothers with and without diabetes for fat content in breast milk or placenta (p = 0.975 and 0.107, respectively) or the sum of the most prevalent BDE congeners (p = 0.233 and 0.317, respectively). However, the number of diabetic mothers in our data set is too small to draw any firm conclusions from these results. In conclusion, the association between perinatal exposure to PBDEs and congenital cryptorchidism was significant after exclusion of diabetic mothers. Exposure to environmental chemicals is, however, one of many adverse factors that alone, or in combination with each other, may cause testicular maldescent (Main et al. 2007). These additional factors include gestational complications, lifestyle, and genetic factors (Virtanen et al. 2007). The authors declare they have no competing financial interests.