Regionally representative hair mercury levels in Canadian First Nations adults living on reserves

Abstract

Objective The primary objective of this participatory study was to assess the current body burden of mercury among First Nations adults. Methods The First Nations Food, Nutrition and Environment Study (2008–2018) collected regionally representative data from First Nations adults living on reserves south of the 60th parallel. Mercury was analyzed in hair as a preferred biomarker for prolonged exposure. Hair samples, a 5 mm bundle cut from the occipital region, were collected from the participants who gave consent and measured for total mercury concentrations using cold vapor atomic fluorescence spectrophotometry. Results In total, 3404 First Nations adults living in 92 communities provided hair samples. This represents 52.5% of the respondents to the household surveys. The mean hair mercury concentrations were 0.56 μg/g among all participants and 0.34 μg/g among women of childbearing age (WCBA). There were 64 exceedances of Health Canada’s mercury biomonitoring guidelines (44 WCBA, 8 women aged 51+ years, 3 men aged 19–50 years, and 9 men aged 51+ years). Conclusion Current mercury exposure no longer presents a significant clinical health risk in most of the First Nations population south of the 60th parallel across Canada. However, mercury exposure continues to be an ongoing environmental public health concern that requires continued monitoring and assessment. Women of childbearing age (19–50 years) and older individuals living in northern ecozones and Quebec have higher mercury exposures, often exceeding Health Canada’s guidelines. Careful risk communication and risk management programs need to focus on northern ecozones and Quebec.

The First Nations Food, Nutrition and Environment Study (2008–2018)—rationale, design, methods and lessons learned

“…This is corroborated by the hair mercury monitoring results. While most (95.5%) of the 3404 participants who provided hair samples had mercury levels below the Health Canada mercury guideline of 2 μg/g, women of childbearing age (19-50) and older individuals (51+) living in northern ecozones and Quebec tend to have a higher hair mercury exposure (Tikhonov et al 2021).…”

“…The lessons learned from the Study and the significance of the results are discussed. Detailed methods and findings for each component are presented in the accompanying papers in this Special Issue of the Canadian Journal of Public Health (Batal et al 2021a-e;Marushka et al 2021aMarushka et al , 2021bChan et al 2021;Tikhonov et al 2021;andSchwartz et al 2021a, 2021b).…”

“…For example, hair sampling for mercury analysis was challenging because, in some First Nations, hair has special spiritual and cultural significance, though traditions and culture vary from nation to nation. This, and other sampling limitations, resulted in only 52.5% (33.4% to 66.5% across the regions) of the respondents to the household surveys providing hair samples (Tikhonov et al 2021). Alternative methods that are more acceptable may need to be offered, e.g., collection of blood samples.…”

Can scientists and knowledge keepers sit comfortably together? An Indigenous physician’s reflections on a decade of participatory research into First Nations nutrition, environment and health

“…In this context, the ideas about an ethical space 1 , which may be created through an honest and sincere engagement of contrasting perspectives of the worldview (Ermine, 2007), were very influential in pointing the clear way to engage in research initiatives combining Indigenous leadership and guidance and science methodologies on a long-term basis (Personal communication, Tikhonov C, 2021). These ideas asserted that the creation of such ethical space bridging differing philosophies and approaches would advance a dialogue to set the conditions for an agreement to collaborate on a research initiative modelled on appropriate ethical guidelines and guiding principles.…”

“…This analysis aims to present the best available evidence and estimate whether there is any health risk from these pollutants at the assessed levels of dietary exposure. Tikhonov et al (2021) describe the human biomonitoring survey of 3404 First Nations adults who participated in all components of FNFNES and provided hair samples to be analyzed for mercury. Results of the current body burden of mercury are further compared with historical data and current guidelines.…”