Human urinary biomonitoring in Western Kenya for micronutrients and potentially harmful elements

Michael J. Watts*, Diana Menya, Olivier S. Humphrey, Daniel R.S. Middleton, Elliott Hamilton, Andrew Marriott, Valerie McCormack, Odipo Osano

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

Spot urinary elemental concentrations are presented for 357 adults from Western Kenya collected between 2016 and 2019 as part of a wider environmental geochemical survey. The aim of this study was to establish population level urinary elemental concentrations in Western Kenya for micronutrients and potentially harmful elements for inference of health status against established thresholds. For elements where thresholds inferring health status were not established in the literature using urine as a non-invasive matrix, this study generated reference values with a 95% confidence interval (RV95s) to contextualise urinary elemental data for this population group. Data are presented with outliers removed based upon creatinine measurements leaving 322 individuals, for sub-categories (e.g. age, gender) and by county public health administrative area. For Western Kenya, reference values with a 95% confidence interval (RV95s) were calculated as follows (μg/L): 717 (I), 89 (Se), 1753 (Zn), 336 (Mo), 24 (Cu), 15.6 (Ni), 22.1 (As), 0.34 (Cd), 0.47 (Sn), 0.46 (Sb), 7.0 (Cs), 13.4 (Ba and 1.9 (Pb). Urinary concentrations at the 25th/75th percentiles were as follows (μg/L): 149/368 (I), 15/42 (Se), 281/845 (Zn), 30/128 (Mo), 6/13 (Cu), 1.7/6.1 (Ni), 2.0/8.2 (As). 0.1/0.3 (Cd), 0.05/0.22 (Sn), 0.04/0.18 (Sb), 1.2/3.6 (Cs), 0.8/4.0 (Ba) and 0.2/0.9 (Pb). Urinary concentrations at a population level inferred excess intake of micronutrients I, Se, Zn and Mo in 38, 6, 57 and 14% of individuals, respectively, versus a bioequivalent (BE) upper threshold limit, whilst rates of deficiency were relatively low at 15, 15, 9 and 18%, respectively. Each of the administrative counties showed a broadly similar range of urinary elemental concentrations, with some exceptions for counties bordering Lake Victoria where food consumption habits may differ significantly to other counties e.g. I, Se, Zn. Corrections for urinary dilution using creatinine, specific gravity and osmolality provided a general reduction in RV95s for I, Mo, Se, As and Sn compared to uncorrected data, with consistency between the three correction methods.

Original languageEnglish
Article number113854
JournalInternational Journal of Hygiene and Environmental Health
Volume238
DOIs
Publication statusPublished - 05 Oct 2021
Externally publishedYes

Bibliographical note

Funding Information:
This research was supported by the BGS-NERC grant NE/R000069/1 entitled Geoscience for Sustainable Futures and BGS Centre for Environmental Geochemistry programmes for financial support. It was delivered via the BGS Eastern Africa Official Development Assistance (ODA) Research Platform. We would like to thank the many people who assisted in the collection of samples, including the Public Health Officers from each county administrative area and in particular the field and laboratory staff from the University of Eldoret (UoE), Moi University (Moi U) and BGS. David Samoie, Doreen Meso, Charles Owano (UoE), Esilaba Anabwani, Amimo Anabwani (Moi U), Nicholas Porter, Sophia Dowell (BGS). Thanks also to David Gardner at the University of Nottingham School of Veterinary Sciences for creatinine and osmolality measurements. This manuscript is published with the permission of the Executive Director of the British Geological Survey.

Funding Information:
This research was supported by the BGS-NERC grant NE/R000069/1 entitled Geoscience for Sustainable Futures and BGS Centre for Environmental Geochemistry programmes for financial support. It was delivered via the BGS Eastern Africa Official Development Assistance (ODA) Research Platform. We would like to thank the many people who assisted in the collection of samples, including the Public Health Officers from each county administrative area and in particular the field and laboratory staff from the University of Eldoret (UoE), Moi University (Moi U) and BGS. David Samoie, Doreen Meso, Charles Owano (UoE), Esilaba Anabwani, Amimo Anabwani (Moi U), Nicholas Porter, Sophia Dowell (BGS). Thanks also to David Gardner at the University of Nottingham School of Veterinary Sciences for creatinine and osmolality measurements. This manuscript is published with the permission of the Executive Director of the British Geological Survey.

Publisher Copyright:
© 2021

Keywords

  • Creatinine
  • Hydration correction
  • Kenya
  • Micronutrients
  • Potentially harmful elements
  • Reference values
  • Urinary biomonitoring

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health

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