Preschoolers and school-age children eat a large number of contaminants in a variety of foods at levels that have known health effects, according to a study of kids and adults in California. Exposure to the pollutants at the levels identified in the study is associated with a wide array of health effects including cancer, liver toxicity, and damage to the neurological and reproductive systems.
The youngest children had higher exposures than school-aged children, parents, or older adults when comparing by body weight, according to researchers at UC Davis and UCLA. To find the exposure levels, the researchers asked participants how much and how often they ate certain foods then used national databases to estimate the amount of toxic chemicals they had eaten.
The study is a first step toward evaluating exposures to harmful environmental chemicals through food. It is important to identify these exposure routes since simple lifestyle changes can reduce them. The amount of chemical exposures adults and children receive every day through food is not well studied. Many factors complicate the issue, including the variety of foods — how they're grown, cooked, processed and packaged — as well as personal differences, such as what kinds, how often, and how much is eaten.
Children are particularly vulnerable to chemicals because their brain and organ systems are developing. Any disruption to developing organs can lead to disorders and health risks later in life. In addition, children eat more per body weight than adults, exposing them to higher levels of chemicals.
The research is part of the US Environmental Protection Agency (EPA) Study of Use of Products and Exposure-Related Behavior (SUPERB) that examines how food and personal and home care products, and timing of exposures, can affect exposure to environmental chemicals. The participants were from 21 counties in California. Adults answered telephone survey questions for themselves and their children about how often and how much of 44 key foods and food groups they had typically eaten in the past year.
Data from government agencies and nonprofit organizations were used to estimate the levels of eleven pollutants from four major contaminant groups that represent different chemical classes, food groups and health effects. These were: metals (arsenic, lead, mercury), pesticides (chlorpyrifos, permethrin, endosulfan), persistent organic pollutants (POPs) (dioxin, DDT, dieldrin, chlordane), and processing byproducts (acrylamide).
Acrylamide occurs naturally when carbohydrate-rich foods are cooked at high temperatures. It is commonly found in crackers, cookies, and french fries.
The researchers calculated the participants' chemical exposures based on their reported diet and the amount of chemicals estimated to be in each food. The data were grouped by age and adjusted for body weight: preschoolers (two to four years), school-age children (five to seven years), parents of young children, and older adults.
Contaminants that were higher than EPA's daily oral intake dose were identified as posing cancer or non-cancer health risks because they exceeded the agency's benchmarks based on known risks for these types of exposures.
Preschoolers and school-aged children were by far the most exposed groups. Both age groups ate contaminants at levels with known health effects, including cancer, liver toxicity, and damage to the neurological and reproductive systems.
Preschoolers exceeded the cancer benchmarks for arsenic and the pesticides dieldrin, DDE and PCDD/Fs. When compared to school-aged children, preschoolers were more likely to consume higher levels of acrylamide, lead, chlordane, dieldrin, DDE and PCDD/Fs. When compared to adults, preschoolers were more likely to be exposed to acrylamide, arsenic, lead, mercury, dioxins/furans (PCDD/Fs), and the pesticides chlorpyrifos, endosulfan, chlordane, dieldrin, and DDE.
For non-cancer effects, more than 95 percent of preschool and school-aged children exceeded the benchmark for acrylamide, while all of them exceeded non-cancer benchmarks for lead and DDE, a metabolite of DDT. EPA's daily intake levels for no risk of effect for both lead and DDE are zero.
Overall, the younger age groups were more likely to have higher exposures than the older age groups based on body weight. For example, preschoolers were more likely to have higher exposures to each contaminant group than school-aged children and adults. School-aged children were more likely to have higher contaminants than parents and parents were more likely than older adults.
Not surprisingly, the primary sources of the exposures were traced to expected food culprits.
• Processed foods — such as crackers, chips, and french fries — were the primary source of acrylamide.
• Fish was the primary source of arsenic and mercury exposures.
• Pesticide exposure was particularly high in fruits and vegetables, including tomatoes, peaches, apples, peppers, grapes, lettuce, broccoli, strawberries, spinach, pears, green beans, and celery.
• Dairy and meat products contained other pesticides such as chlordane, DDE and PCDD/Fs.
Health effects from these chemical exposures could be significant, although the study did not focus on health effects. Exposure to acrylamide may induce neuromuscular effects. Lead exposure can damage the nervous and reproductive systems and is thought to be harmful at any level. Some of the pesticides have known cancer risks, neurotoxicity and reproductive effects.
While these chemicals may seem unavoidable, the researchers suggest ways to lower exposures and protect against health risk. For example:
• Reduce acrylamide exposure by avoiding or limiting highly processed foods — such as cereals, crackers, cookies, potato chips, and French fries.
• Eat organic produce and drink organic milk when possible to reduce pesticide exposures.
• Thoroughly wash non-organic fruits and vegetables to reduce pesticide exposure.
• Decrease meat and dairy products to reduce exposures to persistent organic pollutants, since these chemicals accumulate in fats and can biomagnify in the food chain.
• When selecting fish, choose varieties low in methyl mercury — such as catfish, salmon, and scallops — in place of varieties with high levels — including shark and swordfish.
Contaminants in the participants' blood or urine were not measured. Instead, the exposure estimates were based on self-reports and national databases for chemical exposures.
The same limitations for this study apply as for other self-reported data. People typically underestimate eating "bad foods" and overestimate healthy foods. Even so, the estimated levels identified in this study were in line with other studies that relied on food diaries.
In addition, no heath-related effects were measured in the participants. Instead, health risks were evaluated based on known effects and their estimated exposure levels through food.
The authors suggest "further studies are needed to understand the synergistic effects of exposure to multiple dietary toxins, the variability of cumulative dietary toxic exposure — particularly among young children — and the best approaches to limiting exposure to multiple compounds and from multiple routes."
This report was originally published by EnvironmentalHealthNews.org