A multiyear study of more than 400 new mothers in Minnesota has found elevated mercury levels in those who use skin-lightening cream and consume certain types of fish.

While the risks of mercury exposure have long been linked to certain cosmetics and fish, researchers with the Minnesota Department of Health said it was important to work backward with this study by testing mercury levels in women and then establishing that those with high levels had used these higher-risk products. The results, announced Tuesday, showed higher levels in women with East Asian and African backgrounds.

“It’s one thing to say there is mercury in a skin-lightening product, it’s another to say we found it in women’s bodies in higher levels,” said Jessica Nelson, who led the study, called the Minnesota Family Environmental Exposure Tracking, or FEET.

Public health officials hope the findings will convince immigrant and refugee women not to use skin-lightening creams from their home countries, which have been found to contain steroids and other harmful substances in addition to mercury. The findings come as state lawmakers consider whether to add as much as $400,000 to the state budget over the next two years to increase public awareness of the health risks.

Mercury is a neurotoxin that is particularly damaging to the healthy growth of children, but it can also damage an adult’s nervous, digestive and immune systems.

Changing minds has been challenging at times because of pervasive stereotypes in many immigrant communities that lighter skin color is more beautiful and more reflective of economic success, said Dr. Tseganesh Selameab, an internist and clinic medical director at HealthPartners’ Center for International Health.

“It’s hard to convince women that it might have long-term health effects” when they believe it has immediate effects on their social stature, she said.

Selameab said the study targeted a group of women who might be particularly susceptible to the public health warnings because they will be motivated to protect their children. The study involved taking urine and cord blood samples from the women when they gave birth at Regions Hospital in St. Paul or Abbott Northwestern Hospital in Minneapolis.

When researchers found elevated mercury levels, they interviewed the women to trace the potential sources of contamination. When they discovered that skin-lightening creams were involved, they also conducted air quality tests in the women’s homes. They discovered in some cases that merely opening the skin cream canisters spread mercury particles in the air, meaning that anyone in the homes could be at risk.

“Just by removing the lid of that product, the air levels maxed out the machine” measuring mercury content, Nelson said.

The FEET study was part of a broader program within the Health Department to identify environmental health hazards. The program also was instrumental in identifying a harmful chemical compound known as PFAS in east metro drinking water supplies.

The study’s finding of a mercury link to fish was consistent with the Health Department’s existing guidance, which instructs consumers to eat certain types (including walleye and bass) no more than once per month. The website Chooseyourfish.org provides guidance on fish consumption to minimize mercury exposure risk.

Light skin bias

The attention to the risk of skin-lightening creams was welcomed by Amira Adawe, who has studied the cultural underpinnings of the problem in the Somali immigrant community since 2011. She created the nonprofit Beautywell Project to change social norms in a way that discourages use of the harmful creams.

In addition to lobbying for the state public health funding, the organization has hosted community education events and will conduct summer leadership seminars to empower young women and make them more confident in their natural appearances, Adawe said.

The bias toward light skin started with European colonization but continued long after independence in many African nations and in immigrant communities that emerged in the United States, Adawe said.

“When the colonization ended, [skin bias] didn’t end … because it became part of the culture,” she said. “This is the price we’re paying now.”