The study – published in Environmental Health – measured the levels of food-borne toxin exposure in children and adults by pinpointing foods with high levels of toxic compounds and determining how much of these foods were consumed.
Led by Rainbow Vogt from the University of California, USA, the research team reveal that preschool children are at a high risk for exposure to potentially dangerous toxins including arsenic, dioxins and acrylamide.
The researchers reveal that established cancer benchmark levels were exceeded by all children for arsenic, dieldrin, DDE, and dioxins; while non-cancer benchmarks were exceeded by more than 95% of preschool-age children for acrylamide and by 10% of preschool-age children for mercury.
"We focused on children because early exposure can have long-term effects on disease outcomes," said Vogt. "We wanted to understand the cumulative risk from dietary contaminants.”
“The results of this study demonstrate a need to prevent exposure to multiple toxins in young children to lower their cancer risk," he added.
The researchers warned that dietary strategies are needed to reduce exposure to such potentially toxic compounds, especially where cancer and non-cancer benchmarks are exceeded by children.
"We need to be especially careful about children, because they tend to be more vulnerable to many of these chemicals and their effects on the developing brain," said Professor Irva Hertz-Picciott, senior author of the study.
Study details
The researchers used data from the 2007 Study of Use of Products and Exposure-Related Behavior (SUPERB), which surveyed households in California with children between two and five to determine how their diets, and other factors, contribute to toxic exposure. Specifically, SUPERB focused on 44 foods known to have high concentrations of toxic compounds.
These compounds included metals such as arsenic, lead and mercury; pesticides like chlorpyrifos, permethrin and endosulfan; persistent organic pollutants like dioxin, DDT, dieldrin and chlordane; and the food processing by-product acrylamide.
The team then assessed the risk of toxin exposure by comparing consumption levels to established benchmarks for cancer risk and non-cancer health risks.
Vogt and her colleagues reveal that all of the 364 children studied consumed levels of arsenic, dieldrin, DDE and dioxins that exceeded cancer benchmarks. They added that more than 95% of preschool children exceeded non-cancer risk levels for acrylamide.
Overall they said intakes exceeded benchmark levels for acrylamide, arsenic, lead, chlordane, dieldrin, DDE.
“This is especially of concern for children because all of these compounds are suspected endocrine disruptors and thus may impact normal development,” said the researchers. “These compounds have been linked to cancer, developmental disabilities, birth defects and other conditions.”
Policy issues
Deborah Bennett, an associate professor who also co-authored the study warned that the ginfdings also highlight a number of policy issues around the way food is grown and the way in which potentially toxic compounds are approved.
She noted that while the pesticide DDT was banned 40 years ago, the new study shows significant risk of exposure to DDE – which is a metabolite of DDT.
"Given the significant exposure to legacy pollutants, society should be concerned about the persistence of compounds we are currently introducing into the environment," said Bennett.
"If we later discover a chemical has significant health risks, it will be decades before it's completely removed from the ecosystem."