Long Term Mercury Exposure Linked to Increased Youth Suicide Risk: Study

Young people are more likely to attempt suicide if their mothers and grandmothers were exposed to mercury, according to the findings of a new study biologically that suggests mercury poisoning side effects can have mental health effects across family generations.

Mercury is a naturally occurring chemical element, which has long been known to be toxic, and it can never be fully removed once it pollutes an environment. Even small levels of mercury exposure through skin contact, eating contaminated food, or breathing its vapors is known to increase the risk of mental health problems, nerve damage, and vision or speech impairment.

In a new study published last week in the medical journal Environmental Health Perspectives, Canadian researchers indicate they have identified a three-fold increase in youth suicide attempts inside a community that has a mercury-contaminated water supply dating back over five decades, suggesting the risks extended to subsequent generations.

Mercury Exposure Health Concerns

Despite mercury’s established links to health risks, it is still widely used as an ingredient in some consumer products, and poses a continuing health risk in the U.S.

In 2020, federal health officials warned about potential side effects from dental fillings containing mercury, indicating they can release toxic vapors into the body. Health officials banned dentists from flushing mercury-contaminated wastewater in 2016, in response to concerns that the practice increased mercury levels in surrounding community water supplies.

In 2022, news reports raised concerns about mercury exposure from skin whitening beauty creams after a woman using those products suffered permanent partial vision loss.

Increased Youth Suicide Risks Linked to Mercury Exposure

For this latest study, researchers from the University of Quebec analyzed the Grassy Narrows First Nation, an indigenous community in Ontario, Canada.

Between 1962 and 1970, a chemical company dumped nine tons of industrial waste containing mercury into a river surrounding the community. As a result, the river’s ecosystem, including fish, was highly contaminated. Fish are a noted staple food source for the Grassy Narrows community.

The researchers evaluated information from a Grassy Narrows community health assessment survey from 2016, when over 90% of the adult population was born after the mercury dumping. Then they examined mercury biomonitoring data on the community dating back to the early 1970s to establish mercury exposure across generations. Biomonitoring data included hair, blood, and umbilical cord blood samples.

The community health assessment survey included eighty mothers under age 35 with children aged 12-17. It asked the mothers how often they ate fish from the contaminated river during childhood and pregnancy. It also asked them how often their own mothers ate the contaminated fish.

Additionally, the survey asked the mothers to rate their mental health and their children’s mental health, including any known suicidal thoughts or suicide attempts.

When analyzing the survey responses, researchers associated the mothers’ fish consumption with high suicide risk levels in their children. Specifically, 27% of mothers who ate fish more than once a week as children and while pregnant reported at least one suicide attempt by their child during the past year.

Additionally, the surveyed mothers were more likely to experience suicidal thoughts if their own mothers had regularly eaten fish.  The data showed they were 7.5% more likely to have experienced suicidal thoughts in the prior year if their mothers ate fish more than once a week.

After researchers compared the survey responses to the corresponding biomonitoring data, they determined that the surveyed mothers with frequent fish consumption had elevated mercury levels in their body. Their umbilical cord blood mercury levels were especially high, aligning with prior research suggesting that mercury poisoning tends to concentrate in umbilical cord blood, which then passes to a developing fetus during pregnancy.

Youth Suicide Risk Three Times Higher

While summarizing their findings, the researchers determined that the attempted youth suicide rate in the Grassy Narrows community was 41.2% for girls, and 10.7% for boys. Those figures are three times higher than attempted youth suicide rates in other studied indigenous communities not exposed to high mercury levels, they indicated.

They concluded that long term, elevated mercury exposure is biologically linked to increased mental health issues, including suicidal thoughts and suicide attempts, across family generations.

In outlining their findings, researchers stressed the need for public health measures to limit mercury and other toxic substances in water supplies and consumer products. They pointed to the long term mercury poisoning observed in the Grassy Narrows community as a cautionary example of the health impacts it can have across families.

To prevent future generational mercury poisoning impacts, the researchers urged lawmakers to continue advancing legislation that protects vulnerable consumers, such a recent 2021 bill seeking set limits on mercury, lead, and other toxins in baby food.

“Understanding the intergenerational harm that was done to the people of Grassy Narrows should serve to support efforts to restore the health and well-being that this community enjoyed prior to the discharge of mercury into the river system of their traditional territory,” they wrote. ”From a public health perspective, a community-based interdisciplinary approach would be useful to understand and act upon the social, economic, historical, cultural, physiological, and psychological consequences of this and other environmental disasters.”