Worrisome levels of potentially cancer-causing metal found in children’s diets

Young children are being exposed to a potentially cancer-causing heavy metal known as cadmium through many of the foods they eat, often at levels that exceed safety standards, according to a new study. 

Cadmium has been shown to contaminate water, air and crops, including a range of foods considered  healthy that are used in baby food. The study, which was published last week in the journal  Food and Chemical Toxicity, found that the cumulative average daily levels of cadmium ingested by children were higher than daily cadmium intake levels considered safe by the US Agency for Toxic Substances and Disease Registry (ATSDR).

For instance, children between 6 months and 24 months who consumed spinach and rice at least once a week ingested cadmium that exceeded the ATSDR guidelines by up to 200%, the study determined. The authors of the study warned that the findings are particularly concerning because the bodies of young children are still developing, and may be more susceptible to the effects of heavy metal exposure. 

The study comes after a 2021 US Congressional report showed dangerous levels of metals in infant food, prompting the US Food and Drug Administration (FDA) to launch a research and action plan to assess the risks of heavy metals in foods. 

Cadmium occurs naturally in soil, but the main sources of cadmium pollution in the environment are the burning of fossil fuels, waste incineration, mining, and fertilizer manufacture, according to the US Environmental Protection Agency (EPA). Cadmium from industrial sources can settle on agricultural fields via air pollution, or contaminate crops through cadmium-laden water.

Cadmium has long been a known threat to public health. The EPA classifies the metal as a probable carcinogen, and cadmium has also been linked to other health problems, such as kidney dysfunction. 

Toxic toddler diets

The primary sources of cadmium exposure for all Americans include leafy green vegetables, cereal grains, potatoes, nuts, and seeds. Researchers estimated the exposure risks of different age groups by evaluating the typical diets of those age groups, as well as how often they consumed six foods with high cadmium levels: rice, spinach, oats, barley, potatoes, and wheat. Researchers found that children aged 6 months to 5 years old had the highest exposures to those foods high in cadmium, many of which are  common ingredients in commercial infant food, according to the study.

Exposures to cadmium in children are important to track as children consume more food and fluids relative to their body weight, increasing the risk of cadmium accumulating in their body tissues. Children may also be more likely to suffer adverse impacts of cadmium exposure due to their still-developing bodies, making them a “vulnerable” population, according to the new study. 

Past research has shown links between cadmium exposure and possible neurological effects in children.

Since the researchers only evaluated the risk of cadmium exposure for six foods, cumulative exposure from all foods consumed in the US could be much higher, according to the paper. 

Reducing cadmium exposures

Reducing cadmium exposure for children may mean that infant food manufacturers must change the ingredients they use, according to the 2021 Congressional report on heavy metals in baby food. 

“Step one to restoring that trust is for manufacturers to voluntarily and immediately reduce the levels of toxic heavy metals in their baby foods to as close to zero as possible. If that is impossible for foods containing certain ingredients, then those ingredients should not be included in baby foods,” the authors of that report wrote. 

Parents should decrease the number of days per week a child is exposed to cadmium from specific foods, such as rice and spinach, by feeding children a varied diet, according to Katarzyna Kordas, a professor of environmental health at the University at Buffalo who was not involved in the new study. “Offer many different foods during the week,” she said.

Reducing the amount of cadmium that enters the food supply in the first place is also key, experts say.

Scientists are studying the ways that different food crops take up cadmium, with the hopes to identify varietals of crops that incorporate less cadmium from the soil, said Kordas. The FDA has also recommended that manufacturers reduce the use of cadmium in food-production equipment.

Last year, the Center for Biological Diversity (CBD), an environmental advocacy group, filed a lawsuit against the EPA for nearly tripling the cadmium levels allowed in fresh water, which the group claimed would harm endangered fish and sea turtles. Fossil fuel burning and the use and production of fertilizers contribute more than 90% of cadmium found in fresh water, according to CBD.

“A cleaner environment overall, from air to water, would help reduce food contamination, and regulation of industries and their processes would help in this,” said Kordas.