Urban Environmental Quality and Human Health: Conceiving a Sustainable Future

Impact of Plastics on Health: DEHP and BPA

Ask students to recall how we interact with plastic: We eat foods that are wrapped in plastic, we drink water from plastic bottles, children play with plastic toys, babies drink from bottles, it's in our clothes and carpet and we eat fish from the ocean. Can plastic or the chemical additives end up inside of us?

There are many chemicals added to polymers to create plastics as mentioned earlier. The two that I will focus on as a model that are shown to have the greatest negative impact on our health are DEHP and BPA. Until recently there were few studies on the safety of these chemicals because they are so beneficial in the manufacturing process due to their variability of use and low cost - the manufacturers, government, and consumers have been more focused on benefits.

These two chemicals are used in medical and dental supplies, water bottles, food packaging, and baby bottle nipples. In fact, DEHP and BPA can be found in almost all plastics. Children's toys are almost always carriers of these toxins even video games! Ask children to think about what their younger siblings do with their toys particularly infants. They put them in their mouths! We eat foods wrapped in these toxins, sleep in beds made of them, and drink from milk cartons and water bottles - we are feeding these toxins to ourselves. When we consume toxins we run the risk of getting sick.

The Food and Drug Administration (FDA) is the government agency designed to regulate companies and inform the public about the safety of our food and drugs. Food and drugs have to be packaged therefore; the packaging is also under their jurisdiction. So, it is the FDA's job to regulate and test products for the safety of these chemicals. They do this by testing and then recommending the amount or dose of certain chemicals to ensure safety. This can be compared to the food pyramid and the recommended daily allowances of certain foods (also created by the FDA).

The FDA's recommendation for BPA and DEHP are based on averages. Why might this be a problem? This could be demonstrated by having each student secretly grab what they believe to be an average amount of popcorn or candy. Then have them compare amounts and draw the conclusion that average can be relative to size. This could be further explored by having kindergarten or first grade students do the same thing then have the class compare the younger kids with the older ones. The class could then draw parallels to average chemical doses. You could also use medicine as an example in that kids take smaller amounts than adults because they weigh less. In the end, they should understand that the recommended daily allowance of chemicals such a BPA and DEHP should be different for children than adults - it is not. The other alarming issue is that of exposure since there is no way of knowing how much of these chemicals we are ingesting in a day. Also, what about daily accumulation over time? These factors are also not taken well enough into account.

The FDA uses animals to test the safety of food, drugs and chemicals. How sure can we be that humans will respond the same way? The answer is alarming either way - if we do then the health effects are quite disturbing; if we don't, then what does happen to humans?

BPA when tested on mice at lower than FDA recommended allowances (which were set in 1988) resulted in many abnormal health effects: female and male reproductive abnormalities such as early puberty, reduced sperm count, and genital irregularities. There is evidence of prostate disease and cancer, diabetes, obesity, impaired immune function, behavioral effects, and brain effects. The behavioral effects include hyperactivity and aggression. The brain effects may cause impaired learning and atypical social behaviors.¹²

Ninety five percent of urine samples from people in the U.S. have BPA ¹³ and children have higher concentrations than adults. When compared to the rise in the diseases associated with BPA exposure to the rise in production of things like plastic water bottles (one of the most common carriers of BPA) one can question the recommendation of the FDA for this chemical. In fact, we can question whether it should be on the market period.

Children are the most susceptible due to their low body weight, higher rate of consumption, and they breathe faster. Children commonly consume foods from cans such as infant formula, chicken soup, and ravioli. These products have higher than average levels of BPA.¹⁴ It seems that children are getting exposed at higher rates via baby bottles, sippy cups, and water bottles as well. The country of Canada and Patagonia Inc. pulled polycarbonate bottles (Nalgene bottles) from their shelves all together in 2007 and 2005 respectively.¹⁵ Yet the FDA continues to see no real problem with BPA.

DEHP is as disturbing. The health effects of DEHP in human testing are most disheartening for infant males: male reproductive malformations, sperm damage, asthma, and thyroid effects. They are exposed while still in the womb via medical procedures performed on their mothers, breast milk, food, and mouthing DEHP infested objects. There are also implications for females including: early puberty, female reproductive tract disease, and premature delivery.¹⁶

Four years ago, China banned the use of PVC with DEHP in food wrappers due to its harmful effects.¹⁷ It seems that fatty, oily foods like meat absorb the DEHP and it is then transferred to humans. Heating foods in plastic containers increases the concentration of DEHP.¹⁸

The potential effects of these chemicals on human health are alarming to say the least. There are other chemicals found in plastics that are questionable as well. I have provided details on the two most common as a model of the possible effects on human health however, when the students complete the inventory in the first student activity they may or may not identify DEHP and BPA as an ingredient in the most common plastic trash. The lesson is designed for students to research the particular plastic they identify as the most abundant in the classroom and find the implications for the environment and human health. The students will then explore our current recycling system for plastics.