Correlation of the antimony concentration of umbilical cord and infant hair measured by hydride generation–atomic fluorescence spectrometry

The concentration of antimony in 96 umbilical cord and matched infant hair samples from a set of mother/baby pairs has been determined by hydride generation–atomic fluorescence spectrometry following closed vessel microwave digestion of the samples. Antimony was detected in 90% of the hair samples (limit of detection 3 ng g−1) and also in 90% of the cord samples (limit of detection, 1 ng g−1). For cord samples the mean (median) value was 27.7 (9.0) ng g−1 (n=87) with the distribution being heavily skewed towards lower concentrations with 73% of samples having concentrations less than the mean value. An additional three samples revealed concentrations greater than 200 ng g−1 and have been excluded from the mean calculation. For the hair samples (n=102) the concentration range was much wider (from <3 ng g−1 to >25 000 ng g−1) with a mean (median) of 826 (360) ng g−1 (n=83). A total of 11 samples (11%) showed no detectable antimony (<3 ng g−1) whereas 8 samples (8%) had concentrations which exceeded the mean by an order of magnitude and were thus excluded from the mean calculation. Again the distribution was asymmetrical with 70% of the samples included in the calculation of the mean falling below this concentration. The hair : cord ratio was approximately 40 : 1 (median/median, wet weight basis). No correlation was established between the hair and cord concentrations in the matched pairs of samples. Although these concentrations are considerably less than those found in various tissue samples after treatment with antimony based drugs or following occupational exposure, nevertheless these results indicate that antimony is usually present in samples of these types with the likely origin being environmental exposure via food, airborne dust and water.