Dear Editor

We wish to thank Dr Chambers for his interest in our paper.

The tests performed in the hair and meconium are described in the Subjects and Methods section, referencing our original published work. With respect to the question regarding consent, one has to separate a test for clinical diagnosis from a research protocol. Samples are sent to us by several sources for clinical diagnosis: Children's Aid society, as part of their investigation, often need to know whether a neonate was exposed in utero to drugs of abuse. They have the authority to do so, as they serve as the child's legal guardian at that time. They often ask the mother to have her own hair tested too. Neonatologists and other physicians, who have clinical suspicion of maternal drug abuse also send us samples from all over Canada and the USA for clinical testing. We have previously shown that when there is a clinical suspicion , the rate of positivity for cocaine is 30%. When we ourselves conduct research on this population - we obtain institutional ethical approval and informed consent from the mother.

Dear Editor

Nowhere in the paper is it mentioned either who gave consent for meconium and hair from newborns to be obtained nor to the tests which were performed on them. Presumably, it was obtained from a/the parent(s) or somebody given parental responsibility: perhaps this might be clarified?

T L Chambers