Food and Water Learning Hub

Food and Chemical Exposure

Foods are a major source of exposure to both nutritional factors that support good health as well as chemicals that contribute to disease risk. For this reason, dietary exposures are a significant part of the exposome.

We are what we eat: foods are a major source of exposure to both nutritional factors that support good health as well as chemicals that contribute to disease risk. For this reason, dietary exposures are a significant part of the exposome. Learn what chemicals of concern are in our food, and how to protect yourself and your family from them.

Foods and beverages can be a major source of exposure to chemicals of concern including:

  • Pesticides
  • Hormone disruptors
  • Heavy metals (e.g. lead, mercury, and arsenic)
  • Per-and poly-fluoro alkyl substances (PFAS)
  • Microplastics
  • Antibiotics
  • Synthetic hormones
  • Preservatives
  • Artificial colors, flavors, and sweeteners 

Children’s diets are an important pathway for exposure to some environmental chemicals and other contaminants. Children eat a less varied diet and consume more food for their body weight than adults which increases their risk of exposure.

How do chemicals of concern get into our food?

Chemicals of concern may be intentionally added to foods or unintentionally enter food as contaminants though manufacturing and agricultural practices, packaging, and cookware. Increasing evidence suggests that food packaging and containers are a major source of exposure to potentially harmful chemicals including bisphenol A (BPA), phthalates, and PFAS. Manufacturers are not required to disclose the components of packaging materials, making it difficult for consumers to make choices that limit harmful exposures.

  • Canned foods are often lined with BPA, a hormone disruptor. Some manufacturers are replacing BPA with BPS, which also appears to have hormone-disrupting affects, making it difficult to validate the safety of “BPA-free” products.
  • Plastic in lunch boxes can contain lead and PVC (polyvinyl chloride). Lead is known to impair the brain development and has been detected in some name brand lunch boxes. PVC contains hormone disrupting phthalates that can migrate into food and beverages.
  • Agricultural practices contribute to exposures to pesticides linked to cancer and nervous system toxicity. The increase in crops that are genetically engineered to be pesticide-resistant has led to even greater application of pesticides. 
  • Plastic containers with #3, #6, and #7 are recycling symbols that contain chemicals ​that can migrate into foods and beverages. #3 is made with polyvinyl chloride (PVC) that may contain hormone disrupting phthalates. #6 is made with polystyrene and may release styrene, a carcinogen and neurotoxin that migrates into food. #7 may ​the hormone disruptor BPA.
  • Plastic wrap can be made with PVC which contaminates foods with hormone disrupting phthalates.
  • Microwaving or dishwashing plastic can cause chemicals to migrate from packaging into foods.
  • Nanoparticles (e.g. nanosilver) are added to some food packaging to prevent the growth of bacteria migrate into foods. Nanoparticles are not regulated in food packaging; there is no way to know if they are present. More research is needed to assess the safety of nanoparticles in foods. 
Canned foods are often lined with BPA, a hormone disruptor.

What are the health risks from chemicals of concern in food?

The direct health effects from the consumption of pesticide residues and other contaminants in foods are not known, however many of these compounds are known carcinogens or toxic to the nervous system.

  • Cancer  Some common pesticides are linked to cancers in agricultural workers and children. Hormone disruptors that interfere with estrogen such as BPA may contribute to breast cancer risk.
  • Endocrine Disruption Chemicals in plastic packaging and some preservatives and pesticides have been shown to interfere with hormones including estrogen, testosterone, and thyroid hormone. Exposure to these chemicals during pregnancy and early childhood is particularly problematic, contributing to impairments in reproductive and nervous system development.
  • Learning and Behavioral problems Some pesticides and chemicals in plastics like BPA and phthalates are linked to decreased IQ and behavioral problems such as hyperactivity, depression, and anxiety in children.
  • Obesity, Metabolic Disorders and Type 2 Diabetes: Some contaminants and food additives have been termed “obesogens” because they increase risk of obesity. Some studies also show a link between artificial sweeteners and weight gain and increased likelihood of developing Type 2 Diabetes.

How can we reduce our exposure?

Studies have shown that switching from a conventional (non-organic) diet to an organic diet is associated with a reduction in exposure to pesticides and some chemicals. However there are many easy and affordable steps that you can take to reduce exposure to harmful chemicals in foods:

Choose more fresh or frozen foods
  • Choose more fresh or frozen foods, or foods that are packaged in glass. Consume fewer canned foods.
  • If purchasing canned goods, choose cans that are not dented or damaged which increases the chances of chemicals from the lining entering the food.
  • Choose lead-free lunch containers and canvas or cotton lunch bags.
  • Avoid #3, #6 and #7 recycling symbols and choose glass or stainless steel food and beverage containers. If you must use plastic containers choose #1, 2, 4 and 5 and do not heat or freeze foods in them.
  • Choose aluminum foil, paper bags, or parchment paper over plastic wrap.
  • Heat food on the stove or in glass and wash plastic containers by hand.
  • Avoid food containers that claim to be “anti-microbial”.
  • Choose tap water, which is more tightly regulated than bottled. To check for contaminants, request a testing report from your water supplier. If you have well water, have your water tested yearly. If you live in an older home (pre-1986) that may have lead pipes, have your water tested for lead at the tap.
  • Avoid bottled water which has been shown to contain microplastics (small particles of plastic debris), heavy metals, and PFAS. Plastic production is also a major contributor to climate change.
Look for the USDA Organic seal
  • Look for the USDA Organic seal or Non-GMO Project Verified label. Products that contain some GMO ingredients such as corn and soy may have higher pesticide residues than non-GMO products.
  • Certain produce has been shown to have higher levels of pesticide residues, including apples, celery, cherries, grapes, kale, peaches, spinach, strawberries, and tomatoes.  Look for the USDA Organic seal, or ask about growing practices at your local farmers markets, as small farmers may use minimal or no synthetic chemicals.
  • If you can’t buy organic, maintain a varied diet and choose produce that has been found to have lower levels of pesticide residues, such as asparagus, avocados, broccoli, cabbage, cantaloupes, cauliflower, eggplants, onions, and sweet corn.  
  • Choose foods with natural coloring from vegetables, fruits, or spices (e.g. beets, turmeric, annatto).
  • Choose honey, real maple syrup, or agave over artificial sweeteners.
  • Choose meats labeled “uncured” or “no nitrates added”.
  • Choose foods that use natural preservatives such as Vitamin C, citric acid, or Vitamin E (tocopherols).
  • Avoid antibiotics by choosing USDA Certified Organic meat and dairy, which by definition cannot be treated with antibiotics and choose meat and dairy products from animals raised without antibiotics.
  • Avoid synthetic hormones and choose meat and dairy products labeled “hormone-free” and dairy products labeled rBST or rBGH free.

Beware of greenwashing! Food manufacturers often mislead consumers into thinking their products are healthy by using terms like “natural” or “ecofriendly”, or images and branding that invoke health and nature. To avoid greenwashing look for USDA Organic or Non-GMO Project Verified labels, and limit processed and packaged foods.