Page 420 - Environment: The Science Behind the Stories

exceeded legal limits in California and bottom), and two brands packaged in 20
industry safety guidelines. “Tetra Pak” paperboard boxes with an
Two brands showed the chemi- inner plastic coating. They placed sam- 15
cal composition of standard municipal ples (as well as tap-water samples as
water treatment—including chlorine, controls) in a “yeast estrogen screen,” a Mean estrogenic activity 10
fluoride, and other by-products of standard test-tube screening procedure
disinfection—indicating that these were that uses yeast cells engineered with 5
identical to tap water. Indeed, an esti- genes to change color when exposed 0
mated 25–44% of bottled water is tap to estrogen-mimicking compounds. Control Glass PET Tetra Pak
water. Companies can essentially just The researchers detected
turn on the faucet, filter the water, bottle estrogenic contamination in 60% Figure 2 estrogenic activity (as
it, and sell it to us at marked-up prices. of the samples (Figure 2). Both determined by a yeast cell culture test)
was highest in bottled water from Tetra
EWG also sent water samples to a Tetra Pak brands and seven of nine Pak containers, followed by PeT plastic
lab at the University of Missouri, where plastic brands contained hormone- containers, and then glass containers. A
researchers tested for cancer-causing mimicking substances that apparently negative control showed no appreciable
effects in cell cultures. Their assays leached from the packaging. So did estrogenic potency. With kind permission from
measure whether a substance causes an three of the glass-bottled brands, Springer Science and Business Media and the
increase in the growth of breast cancer presumably from contamination at author, from Wagner, M., and J. Oehlmann, 2009.
cells. One bottled water brand caused a the bottling plant. Endocrine disruptors in bottled mineral water:
78% increase in cancer cell growth rela- Wagner and Oehlmann then tested Total estrogenic burden and migration from plastic
tive to the control sample, suggesting that whether chemicals in the water would bottles. Environmental Science and Pollution
something in the water was carcinogenic. affect a living animal, a type of snail that Research 16: 278–286, Fig 3a.
Other scientists have compared is known to increase its reproduction
bottled water to tap water in dif- when confronted with an estrogenic water can contain a range of contami-
ferent ways. In 2009, researchers substance. They raised some snails nants, some of which may pose health
Martin Wagner and Jörg Oehlmann of in PET plastic containers and others risks. Tap water may also contain
Johann Wolfgang Goethe University in in glass containers. After 56 days, the plenty of pollutants, but municipalities
Frankfurt, Germany, tested 20 brands snails in the PET containers had pro- are required to test and report on their
of bottled water for the presence of duced 39–122% more embryos than water quality, so it is much easier for
hormone-disrupting chemicals that snails in control conditions, whereas consumers to get information.
mimic estrogen. Endocrine disruptors snails in glass containers showed no For maximum safety and health,
such as bisphenol A, phthalates, and difference. This suggested that estro- the EWG recommends drinking
other compounds found in plastics can genic compounds were leaching from filtered tap water (using a filter on
exert a wide array of health impacts, the plastic. Their results were published your faucet) instead of bottled water.
even at very low doses (Chapter 14). in the journal Environmental Science Depending on the quality of your local
Wagner and Oehlmann compared and Pollution Research. tap water, it may be as good or better
nine brands packaged in glass bottles, Research on the quality and safety than bottled water, even when unfil-
nine brands packaged in plastic bottles of bottled water is just getting started, tered. You can consult water quality
(PET, or polyethylene terephthalate, the but already these studies and others information from your utility to find out
type of plastic with a #1 symbol on the like them have indicated that bottled what you are drinking. CHAPTER 15 • Fr E shwat E r s yst E m s and rE sour CE s

choose to live in floodplains. To protect against floods, When we engineer rivers to stay in their channels, we
communities and governments have built levees (also called often end up increasing the frequency of floods in downri-
dikes) along banks of rivers such as the Mississippi to hold ver areas. Human development also tends to worsen flooding
water in main channels. Many dikes are small and locally because pavement and compacted soils speed runoff, send-
built, but the U.S. Army Corps of Engineers has constructed ing intense pulses of water into rivers. In contrast, forests and
thousands of miles of massive levees along major water- wetlands make flooding less likely because they allow water
ways. These structures prevent flooding at most times and to spread out while vegetation slows its flow and porous soil
places but can sometimes worsen flooding because they soaks it up. Thus, major flood events may become more fre-
force water to stay in channels and accumulate, building quent in developed areas. Indeed, a “100-year flood” is not
up enormous energy and leading to occasional catastrophic something that can occur only once every 100 years. Rather,
overflow events (Figure 15.14). it is a statistical probability: in any given year, there is a 1% 419

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