Abstract
We sought to determine whether milk from smoking mothers also contained a higher concentration of Cd since infants are thought to have a higher Cd absorption than adults. The selenium content of the milk and blood samples was also determined because Se can be the most effective antagonist to Cd and New Zealand breast milk has the lowest reported Se content. The concentration of Cd found in milk from non-smoking mothers is of the same order as reported recently from Sweden (0.1 ng/ml) and from Britain (0.3 ng/ml). Using published milk consumption data it can be calculated that the infants of the smoking mothers were exposed to 20-40% more Cd than the infants of non-smoking mothers. The newborn of women who smoke are known to be at a greater risk of stillbirth and low birth weight, effects similar to those produced by a high Cd exposure in experimental animals. Since smoking does appear to increase the Cd content in breast milk the greater exposure to Cd in infants of smoking mothers is undesirable, particularly in New Zealand where breast milk is very low in Se.