Environmental Science 15th Edition by Scott Spoolman,Tyler Miller

Exercise 18

THE CONTROVERSY OVER BPA
The estrogen mimic bisphenol A (BPA) serves as a hardening agent in certain plastics (especially shatter-proof polycarbonate) that are used in a variety of products, including some baby bottles, sipping cups, and pacifiers, as well as some reusable water bottles, sports drink and juice bottles, microwave dishes, and food storage containers. BPA is also used to make some dental sealants, as well as the plastic resins that line nearly all food and soft drink cans and cans holding baby formulas and foods. This type of liner allows containers to withstand extreme temperatures, keeps canned food from interacting with the metal in the cans, prevents rust in the cans, and helps to preserve the canned food. In addition, individuals can be exposed to BPA when their hands touch the thermal paper used to produce some cash register receipts.
A study by the CDC indicated that 93% of Americans older than age 6 had trace levels of BPA in their urine. While these levels were well below the acceptable level set by the EPA, the EPA level was established in the late 1980s, long before we knew much about the potential effects of BPA on human health. The CDC study also found that children and adolescents had generally higher urinary BPA levels than adults had.
Research indicates that the BPA in plastics can leach into water or food when the plastic is heated to high temperatures, microwaved, or exposed to acidic liquids. A 2009 Harvard University Medical School study found that there was a 66% increase in BPA levels in the urine of participants who drank from polycarbonate bottles regularly for just 1 week.
By 2013, more than 90 published studies by independent laboratories had found a number of significant adverse effects on test animals from exposure to very low levels of BPA. These effects include brain damage, early puberty, decreased sperm quality, certain cancers, heart disease, obesity, liver damage, impaired immune function, type 2 diabetes, hyperactivity, impaired learning, impotence in males, and obesity in unborn test animals exposed to BPA. On the other hand, 12 studies funded by the chemical industry found no evidence or only weak evidence of adverse effects from low-level exposure to BPA in test animals.
In the face of these conflicting and possibly confusing research findings, consumers now have more choices, since most makers of baby bottles, sipping cups, and sports water bottles offer BPA-free alternatives. Also, many consumers are avoiding plastic containers with a #7 recycling code (which indicates that BPA can be present). People are also using powdered infant formula instead of liquid formula from metal cans, choosing glass bottles and food containers instead of those made of plastic or lined with plastic resins, and using glass, ceramic, or stainless steel coffee mugs rather than plastic cups.
Many manufacturers have replaced BPA with bisphenol-S (BPS). However, studies indicate that BPS can have effects similar to those of BPA, and BPS is now showing up in human urine at levels similar those of BPA. There are substitutes for the plastic resins containing BPA or BPS that line 90% of the food cans used in the United States. However, these replacements are more expensive, and the potential health effects of some chemicals they contain also need to be evaluated. Some companies, including Campbell Soup and H.J. Heinz, are phasing out the use of BPA in can liners.
Canada, the European Union, and six states have banned the sale of plastic baby bottles that contain BPA. In 2008, the U.S. Food and Drug Administration (FDA) concluded that BPA in food and drink containers was not a health hazard. However, in 2012, the FDA, while not reversing its general position, banned the use of BPA in baby bottles and sipping cups.
Critical Thinking
Should plastics that contain BPA or BPS be banned from use in all children's products? Explain. Should such plastics be banned from use in the liners of canned food containers? Explain. What are the alternatives?