Two new studies provide information on the association between exposure to heavy metals in food and the risk of cancer and other serious diseases.

The effects of heavy metal consumption are more pronounced in children. The findings were presented at the Society for Risk Analysis’ 2023 annual conference.

Food crops can absorb heavy metals from contaminated soil, air and water. As a result, traces of lead, arsenic and cadmium are found in common foods, from rice and cereals to nuts and spinach.

The problem of food contamination by heavy metals has acquired a new urgency, as high levels were found in baby foods that were pulled from store shelves.

In the first study they were analyzed the effects of lead, a toxic metal, commonly found in old paint, water pipes and contaminated soil. Lead was found to have a moderate to high risk score for causing lung, kidney, bladder, stomach and brain cancer. It also scored moderate to high for hematopoietic, reproductive, neurological, renal, and respiratory effects. Also, the effects were analyzed of cadmium, a toxic metal found in nuts, potatoes, seeds, grains, green leafy vegetables and cigarette smoke. Among its sources in the environment are fertilizers and industrial emissions. In the study, cadmium garnered moderate to high risk scores for prostate, kidney, bladder, breast, pancreatic, and endometrial cancer. It also presented moderate to high scores for non-cancer risks such as renal, developmental, reproductive, immunological and neurological effects.

Earlier this year another study on cadmium in baby food published in the journal Food and Chemical Toxicology found that young children between the ages of six months and five years are most exposed to cadmium in common foods. Ta infants and young children in the US who regularly consumed rice, spinach, oats, barley, potatoes, and wheat had an average exposure to cadmium that exceeded the maximum tolerable intake level established by the Agency for Toxic Substances and Disease Registry.

In the second study presented at the conference, the research team conducted a quantitative assessment of cancer risk for various US foods containing inorganic arsenic. Preliminary estimates indicate that each year more than 6,000 additional cases of bladder and lung cancer and more than 7,000 cases of skin cancer can be attributed to the consumption of inorganic arsenic in the US. The researchers also found that certain foods can be linked to a higher risk of cancer than others, such as rice, wheat and green leafy vegetables.

Heavy metals health risk from fires

Another publication in the journal Nature Communications finds that carcinogenic heavy metals such as chromium may pose an underestimated risk to public health from forest fires.

Researchers analyzed soils and ash after the 2019 and 2020 wildfires in northern California and observed dangerous levels of bioavailable reactive chromium, a known carcinogen, in the wildfire ash that is easily dispersed long distances by wind. This was observed to be more prevalent in areas with mineral-rich geology and was also increased by fire severity.

The researchers found that burning led to elevated levels of reactive chromium in topsoil up to a year after the fire. In dry environments, they explain, this chromium can pose a long-term inhalation hazard from continuous dust generation and wind dispersion.

The findings highlight the public health risk posed by wildfires.

Read the publication here.