Jean-Claude Aubry

Determination of urinary iodine by inductively coupled plasma mass spectrometry.

BACKGROUND Mild iodine deficiency is endemic in many countries of Europe including Belgium. Fast, accurate and specific methods for quantification of urinary iodine are needed. We describe in this report a specific ICP-MS method for the quantification of urinary iodine. METHOD Samples and iodate calibrators were diluted 20 times into aqueous solution containing triton X-100, 1.5% HCl and (103)Rh as an internal standard. Prior digestion or oxidation was not necessary. Results were compared with those obtained by Sandell-Kolthoff (S-K) spectrophotometric method. RESULTS Comparison of both methods showed good agreement. The Passing-Bablok regression between both methods was ICP-MS=0.986 (S-K)-7.51. The Bland-Altman difference plot showed a small but significant mean difference of -13.3 microg/L for ICP-MS. The between-day coefficient of variation (CV) was 13% at 89 microg/L. Limit of detection was 4 microg/L and limit of quantification was 20 microg/L. No carryover effect has been observed on series containing up to 50 samples. CONCLUSION The ICP-MS method described here is fast, accurate and specific for the quantification of urinary iodine. Compared to the S-K method the urinary iodine concentrations measured by the ICP-MS method were slightly, but significantly lower. Consequently, the results of studies using S-K method should be compared with caution with those using the ICP-MS method.

Le bruit en néonatologie, impact du personnel hospitalier.

Resume Objectifs Identifier les differentes sources de bruit presentes dans une unite de soins intensifs neonatals d’un centre hospitalier universitaire et en evaluer le niveau sonore. Methodes Le personnel soignant a ete interroge pour obtenir une appreciation qualitative de l’environnement sonore du service. Des observations quantitatives a l’aide d’un sonometre et d’un dosimetre ont ete ensuite effectuees. Les mesures presentees ont ete realisees en deux emplacements de nouveau-nes : sur une table chauffante et dans un incubateur. Resultats De nombreuses sources de bruit ont ete identifiees dans le service. Elles etaient responsables d’un environnement sonore dont le niveau etait nettement superieur aux recommandations existantes et laissaient peu de periodes de calme. Les alarmes des divers appareils de surveillance et manutention, les pleurs des nouveau-nes et les activites du personnel etaient les principales sources de bruit. Conclusion L’impact du personnel hospitalier sur l’importance et la frequence des sources sonores est essentiel. Une strategie de sensibilisation devrait donc certainement etre prevue.

Quantification of Metal in the Hair of Copper Miners in Katanga Province, Democratic Republic of Congo

This study aims to demonstrate the exposure of artisanal miners to the contents of mineralised gangue and to assess whether the different workstations and their related operating processes potentiate such exposure. The population sampled (n=100) consisted of artisanal miners operating in the mine of Ruashi, in the south of the Katanga copper belt. We made use of hair as a biomarker and performed our analyses using ICP-MS. According to recommendations from the Agency for Toxic Substances and Disease Registry, we have compared our results to those of an unexposed population living in the same area in order to point out the occupational origins of such exposure. In our hair analysis, we identified and quantified 22 elements. For almost all of these elements, the artisanal miners had much higher values as compared to the control population. In addition, non-diggers had higher levels than diggers for almost all of the elements that could be directly linked to those present in the mineralised gangue. Median values obtained for the artisanal miners were systematically higher than those of the control population, reflecting a higher than normal exposure. Such differences between the two sample populations can only be explained by the occupational (mining) origin of exposure, since the living environment, hair nature, sampling method, and analysis techniques were the same for both populations. Medians within the miner samples showed different exposure profiles for non-diggers versus diggers, resulting from the fact that non-diggers were more exposed to the mineralised gangue. The results attest to the reality and the large extent to which artisanal miners in Katanga Province are exposed to chemical components of mineralised gangue. This exposure is more significant within the workstations related to the raw mineral processing phase as opposed to the extraction phase.