The Contribution across Three Generations of Mercury Exposure to Attempted Suicide among Children and Youth in Grassy Narrows First Nation, Canada: An Intergenerational Analysis

Abstract

Background: For 60 y, the people of Asubpeeschoseewagong Anishinabek (Grassy Narrows First Nation) have endured the effects of massive mercury (Hg) contamination of their river system, central to their traditions, culture, livelihood, and diet. In the years following the Hg discharge into the English–Wabigoon River system by a chloralkali plant in the early 1970s, there was a dramatic increase in youth suicides. Several authors attributed this increase solely to social disruption caused by the disaster. Objective: This research examined the possible contribution of Hg exposure across three generations on attempted suicides among today’s children (5–11 y old) and youth (12–17 y old), using a matrilineal intergenerational paradigm. Methods: Information from the 2016–2017 Grassy Narrows Community Health Assessment (GN-CHA) survey was merged with Hg biomonitoring data from government surveillance programs (1970–1997). Data from 162 children/youth (5–17 years of age), whose mothers ( ) had provided information on themselves, their parents, and children, were retained for analyses. Direct and indirect indicators of Hg exposure included a ) grandfather had worked as a fishing guide, and b ) mother’s measured and estimated umbilical cord blood and childhood hair Hg and her fish consumption during pregnancy with this child. Structural equation modeling (SEM) was used to examine significant links from grandparents (G0) to mothers’ exposure and mental health (G1) and children/youth (G2) risk for attempted suicide. Results: Mothers’ (G1) median age was 33 y, 86.3% of grandmothers (G0) had lived in Grassy Narrows territory during their pregnancy, and 52.5% of grandfathers (G0) had worked as fishing guides. Sixty percent of children (G2) were years of age. Mothers reported that among teenagers (G2: 12–17 years of age), 41.2% of girls and 10.7% of boys had ever attempted suicide. The SEM suggested two pathways that significantly linked grandparents (G0) to children’s (G2) attempted suicides: a ) through mothers’ (G1) prenatal and childhood Hg exposure and psychological distress, and b ) through maternal fish consumption during pregnancy (G1/G2), which is an important contributor to children’s emotional state and behavior. Discussion: Despite minimal individual information on G0 and G1 past life experiences, the findings support the hypothesis that Hg exposure over three generations contributes to the mental health of today’s children and youth. The prevalence of Grassy Narrows youth ever having attempted suicide is three times that of other First Nations in Canada. https://doi.org/10.1289/EHP11301

Indigenous Peoples understand human health relies on healthy waters

“…15 In fact, First Nation safe drinking water is considered a crisis where approximately one-third of First Nations face health threats from high-risk drinking water systems. 35 How can First Nations be healthy when they do not have access to healthy waters. A recent research study was published regarding the health of the people in Asubpeeschoseewagong Anishinabek (Grassy Narrows First Nation) explaining how the contamination of their waterways have disrupted their culture, traditions, economy, and the health of the peoples.…”

“…34 The research exposes that contamination of the waters is intergenerational. 35 The effects of unhealthy waters compound over time and even through generations. 26 When the horrific experiences of trauma and loss have not been addressed, it consumes Indigenous Peoples’ health, all four elements of their health, physical, spiritual, mental, and emotional.…”

Invited Perspective: Linking the Intergenerational Impacts due to Mercury Exposure in Grassy Narrows First Nation, Canada

“…concerning the intergenerational effects of MeHg poisoning on children’s mental health. 6 The authors used structural equation models (SEMs) to assess the intergenerational effects of grandmaternal (G0) and maternal (G1) MeHg poisoning on children’s (G2) mental health, including risk of attempted suicide, while controlling for maternal psychological distress and other confounders. The results of this study are both compelling and moving.…”

“…Among the Grassy Narrows cohort, maternal Hg biomarkers (blood or hair) were missing for nearly 50% of the mothers. 6 Blood Hg was transformed into hair equivalents using a hair-to-blood ratio of 1:250. 6 , 17 However, this ratio may range from 1:150 to 1:450, 18 potentially introducing measurement error into the SEMs.…”

“… 6 Blood Hg was transformed into hair equivalents using a hair-to-blood ratio of 1:250. 6 , 17 However, this ratio may range from 1:150 to 1:450, 18 potentially introducing measurement error into the SEMs. As a sensitivity analysis, the authors replaced each mother’s (G1) estimated childhood MeHg exposure by her reported fish consumption at .…”