Intra-household agreement of urinary elemental concentrations in Tanzania and Kenya: potential surrogates in case–control studies

Daniel R.S. Middleton*, Valerie A. McCormack, Michael O. Munishi, Diana Menya, Andrew L. Marriott, Elliott M. Hamilton, Amos O. Mwasamwaja, Blandina T. Mmbaga, David Samoei, Odipo Osano, Joachim Schüz, Michael J. Watts

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


Element deficiencies and excesses play important roles in non-communicable disease aetiology. When investigating their roles in epidemiologic studies without prospective designs, reverse-causality limits the utility of transient biomarkers in cases. This study aimed to investigate whether surrogate participants may provide viable proxies by assessing concentration correlations within households. We obtained spot urine samples from 245 Tanzanian and Kenyan adults (including 101 household pairs) to investigate intra-household correlations of urinary elements (As, Ba, Ca, Cd, Co, Cs, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, S, Se, Sr, Tl, V and Zn) and concentrations (also available for: Bi, Ce, Sb, Sn and U) relative to external population-levels and health-based values. Moderate-strong correlations were observed for As (r = 0.65), Cs (r = 0.67), Li (r = 0.56), Mo (r = 0.57), Se (r = 0.68) and Tl (r = 0.67). Remaining correlations were <0.41. Median Se concentrations in Tanzania (29 µg/L) and Kenya (24 µg/L) were low relative to 5738 Canadians (59 µg/L). Exceedances (of reference 95th percentiles) were observed for: Co, Mn, Mo, Ni and U. Compared to health-based values, exceedances were present for As, Co, Mo and Se but deficiencies were also present for Mo and Se. For well correlated elements, household members in East African settings provide feasible surrogate cases to investigate element deficiencies/excesses in relation to non-communicable diseases.

Original languageEnglish
Pages (from-to)335-343
Number of pages9
JournalJournal of Exposure Science and Environmental Epidemiology
Issue number3
Early online date21 Sep 2018
Publication statusPublished - 01 May 2019
Externally publishedYes

Bibliographical note

Funding Information:
Funding Funding was received from an NIH grant (R21CA191965) with support from BGS Global and the Centre for Environmental Geochemistry. The work reported was undertaken during the tenure of a Postdoctoral Fellowship from the International agency for Research on cancer, partially supported by the European Commission FP7 Marie Curie Actions—People—Co-funding of regional, national and international programmes (COFUND) and a UICC IARC Development Fellowship.

Publisher Copyright:
© 2018, Springer Nature America, Inc.


  • Cancer epidemiology
  • Micronutrients
  • Trace elements
  • Urine

ASJC Scopus subject areas

  • Epidemiology
  • Toxicology
  • Pollution
  • Public Health, Environmental and Occupational Health


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