Survey of Methylmercury Exposures and Risk Factors Among Indigenous Communities in Guyana, South America.

Juliana Persaud,Jorge L Hurtado-Gonzales,L Cynthia Watson,Christopher J Chin

doi:10.5696/2156-9614-10.26.200604

Juliana Persaud, Jorge L Hurtado-Gonzales + Show 2 more

Open Access

https://doi.org/10.5696/2156-9614-10.26.200604

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Abstract

Background.Gold mining activities in forested areas across Guyana have been a common practice for more than a century. The intensification of artisanal and small-scale gold mining (ASGM) in recent decades caused by global market demand is contributing to the mobilization of mercury into aquatic systems. Indigenous populations who consume high levels of locally sourced fish are greater at risk for methylmercury poisoning from ingestion of contaminated fish.Objectives.The aim of the present study was to investigate the levels of mercury contamination and identify the risk factors associated with hair mercury levels in four indigenous communities in Guyana.Methods.Concentrations of total mercury were measured in hair samples from 99 participants from four indigenous communities in the south Rupununi region in Guyana. The findings of this study were compared with those of previous studies to assess the prevalence of mercury contamination in indigenous communities across Guyana.Results.Hair mercury levels were found to be above the World Health Organization (WHO) reference value for residents who live close to ASGM activities and who consume high quantities of locally sourced fish. Our results are not only consistent with those obtained in previous studies, but also evidence that mercury poisoning has become a generalized problem for indigenous communities in Guyana.Conclusions.Fish is the main source of protein for many riverine communities and consumption of mercury-contaminated fish poses a serious health hazard for these vulnerable populations. The situation is especially dire for community members of Parabara with 100% of participants showing elevated (>15 μg*g−1) hair mercury levels. It is therefore crucial that Parabara residents be evaluated by relevant health agencies for clinical symptoms related to mercury toxicity.Participant Consent.ObtainedEthics Approval.The study protocol was approved by the Institutional Review Board of the Ministry of Public Health, Guyana.Competing Interests.The authors declare no competing financial interests.

Highlights

The gold mining industry in Guyana has experienced unprecedented growth in the last two decades to the extent that it dominates the export industry and has become one of the country’s most important economic sectors
With age as a covariate, the generalized linear model (GLM) test showed that the difference between log-likelihoods for the full and reduced models is 92.83, with a p-value < 0.001, which indicates that the model as a whole is significant
The present study showed that indigenous populations in Guyana who live close to artisanal and smallscale gold mining activities and who depend on local fish to supply most of their protein needs are likely to harbor high levels of mercury in their bodies

Summary

Introduction

The gold mining industry in Guyana has experienced unprecedented growth in the last two decades to the extent that it dominates the export industry and has become one of the country’s most important economic sectors.

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Conclusion