Biomarkers of selenium status in the Amazonian context : blood, urine and sequential hair segments
Date
2009
Journal Title
Journal ISSN
Volume Title
Publisher
Nature Publishing Group, Macmillan Publishers
Abstract
Selenium (Se) is an essential element and deficit or excess of dietary Se is associated with health disorders. Relatively elevated Se levels have been reported
in the Brazilian Amazon, where there are also important annual variations in the availability of different foods. The present study was conducted among
six riparian communities of the Tapajo´ s River to evaluate seasonal variations in blood and sequential hair cm Se concentrations, and to examine the
relationships between Se in blood and hair, and blood and urine. Two cross-sectional studies were conducted, at the descending water (DWS, n¼259)
and the rising water (RWS, n¼137) seasons, with repeated measures for a subgroup (n¼112). Blood Se (B-Se), hair Se (H-Se) and urine Se (U-Se) were
determined. Match-paired analyses were used for seasonal comparisons and the method of best fit was used to describe the relationships between
biomarkers. B-Se levels presented a very large range (142–2447 mg/l) with no overall seasonal variation (median 284 and 292 mg/l, respectively).
Sequential analysis of 13 cm hair strands showed significant variations over time: Se concentrations at the DWS were significantly lower compared with
the rising water season (medians: 0.7 and 0.9 mg/g; ranges: 0.2–4.3 mg/g and 0.2–5.4 mg/g, respectively). At both seasons, the relationships between B-Se
and H-Se were linear and highly significant (r2¼67.9 and 63.6, respectively), while the relationship between B-Se and U-Se was best described by a
sigmoid curve. Gender, age, education and smoking did not influence Se status or biomarker relationships. Variations in H-Se suggest that there may be
seasonal availability of Se sources in local food. For populations presenting a large range and/or elevated Se exposure, sequential analyses of H-Se may
provide a good reflection of variations in Se status.
Description
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Journal Article (peer-reviewed)
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Text
Keywords
BRAZILIAN AMAZON, EXPOSURE ASSESSMENT, SE STATUS, SEASONAL VARIATIONS, SEQUENTIAL HAIR, URINE, WHOLE BLOOD, SELENIUM
Citation
Lemire, M., Mergler, D., Huel, G., Passos, C.J.S., Fillion, M., Philibert, A., et al. (2009). Biomarkers of selenium status in the amazonian context: Blood, urine and sequential hair segments. Journal of Exposure Science and Environmental Epidemiology, 19, 213-222.doi:10.1038/jes.2008.14