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. 2018 Jul;30(4):e23130.
doi: 10.1002/ajhb.23130. Epub 2018 May 3.

Geophagic earths consumed by women in western Kenya contain dangerous levels of lead, arsenic, and iron

Joshua D Miller  1 , Shalean M Collins  1 , Moshood Omotayo  2   3 , Stephanie L Martin  4 , Katherine L Dickin  5 , Sera L Young  1
Affiliations

Geophagic earths consumed by women in western Kenya contain dangerous levels of lead, arsenic, and iron

Joshua D Miller et al. Am J Hum Biol. 2018 Jul.

Abstract

Objectives: Geophagy is commonly reported by pregnant women and children, yet its causes and consequences remain poorly understood. Therefore, we sought to determine if geophagy could contribute micronutrients and/or be a source of heavy metal exposure by examining the elemental composition of earths consumed in Kakamega, Kenya.

Methods: Ten samples of earths commonly consumed during pregnancy were collected by study enumerators and analyzed using inductively coupled plasma-atomic emission spectroscopy. Samples were either collected at markets or from walls of participants' homes, based on where participants reported most commonly sourcing their consumed earths.

Results: Based on estimated intakes (40 g/day), all samples had lead levels that exceeded the provisional maximum tolerable daily intake, and one sample exceeded the threshold for arsenic. Further, estimated intakes of iron for all samples were at least 8.9 times higher than the established threshold. Elemental concentrations were also compared by the site of sample collection (market vs. household wall); market samples had significantly higher iron concentrations and lower calcium concentrations than wall samples.

Conclusions: Geophagic earths in Kakamega may be harmful because of dangerously high levels of lead, arsenic, and iron. The prevalence of geophagy among vulnerable populations underscores the importance of understanding its causes and consequences for accurate public health messaging.

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Figures

FIGURE 1
FIGURE 1
Estimated intakes of iron (1A) and calcium (1B) from geophagic samples collected in Kakamega, Kenya, assuming 40g consumed/day and 60kg body weight. Estimated iron intakes are well above safe thresholds. M = market sample; W = wall sample; RDA = recommended daily amount; UL = upper limit; PMTDI = provisional maximum tolerable daily intake
FIGURE 2
FIGURE 2
Estimated intake of lead (2A), arsenic (2B), and cadmium (2C) from geophagic samples collected in Kakamega, Kenya, assuming 40g consumed/day and 60kg body weight. Intakes of lead were above the safety threshold for all samples; one sample exceeded the threshold for arsenic. M = market sample; W = wall sample; PTTIL = provisional tolerable total intake level; BMDL = benchmark dose lower limit; PTMI = provisional tolerable monthly intake
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