,
This assignment is designed to introduce students to thinking about emerging water quality issues and the role of the precautionary principle in the decisions we make about what products to market or use.
INTRODUCTION
A primary goal of environmental science is to identify and examine emerging environmental concerns before they become critical ecological or human health problems. In 1996, the book
Our Sto l en Future (Colborn et al.), raised concerns about the prevalence of certain synthetic chemicals in the environment that can interfere with hormonal messages involved in the control of human and nonhuman growth and development, especially in the fetus. (These are referred to as endocrine disrupt e rs or hormone mimickers.) This book helped focus attention on these and other ubiquitous pollutants in the environment, which had not been studied to the same degree as so-called conventional water pollutants because of their expected low levels. These "overlooked" environmental contaminants include reproductive hormones, steroids, antibiotics, pharmaceuticals, personal care products, detergents, disinfectants, fragrances, insect repellants, and fire retardants.
These compounds and their metabolites have been detected in European waters and, more recently, in U.S. streams.
(Metabolites are byproducts produced from metabolism, the organic processes necessary to sustain life.)
To date, little attention has been paid regarding the potential impact of pharmaceuticals and personal care products on ecological or human health. This concern is exacerbated by a growing population, increased consumption of these products, and increasing worldwide demand for safe freshwater. These compounds enter the environment directly through discharges from public sewage treatment plants and indirectly through wet weather runoff from animal feed lots and excreta from medicated domestic pets (Daughton, 2003).
According to Kolpin et al. (2002), "Surprisingly, little is known about the extent of environmental occurrence, transport, and ultimate fate of many synthetic organic chemicals after their intended use, particularly hormonally active chemicals, personal care products, and pharmaceuticals that are designed to stimulate a physiological response in humans, plants, and animals." A contributing factor to this l ack of data is the lack of analytical \ methods capable of detecting these compounds at the low concentrations expected in the ; environment. The environmental presence of these compounds raises many concerns
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186 _________ PROBLEM SET 10 • Water Quality, Chemicals, and Consumer Choice
(e.g., abnormal physiological processes, reproductive impairment, cancer, and toxicity), but perhaps the biggest concern is that the compounds can contribute to the development of antibiotic-resistant bacteria. If super bacteria evolved through resistance to antibiotics, how would we defend ourselves from harmful bacteria? Kolpin et al.
(2002) conducted the first nationwide reconnaissance of the occurrence of pharmaceuticals, hormones, and other organic wastewater contaminants in water resources. Using a list of 95 contaminants, they identified 139 streams susceptible to contamination across 30 states during 1999 and 2000. Of the assessed streams, 80% had one or more of these contaminants. Some of the most frequently detected compounds were:
N.N-diethyltoluamide (also known as DEET, used as a topical insect repellant)
Caffeine
T ri (2-c h loroethyl)p h osphate (fire retardant used in plastics)
Triclosan (antimicrobial disinfectant)
4-nonylphenol (an ingredient in certain detergents)
For this assignment, we will focus on two compounds of interest: 4-nonylphenol and triclosan.
Although nonylphenol compounds used in detergents have been phased out in Europe, they are still widely used in the United States. Of special concern is 4-nonylphenol, which is one of the wide varieties of environmental chemicals reported to have estrogenic effects, which are thought to mimic the hormone estrogen and potentially affect human and non-human reproduction and development.
Triclosan is used in "antibacterial" and "antifungal" detergents, dishwashing liquid, laundry detergent, deodorants, cosmetics, lotions, creams, toothpastes, and mouthwashes. There are concerns that the widespread use of Triclosan may promote antibiotic-resistant bacteria.
Triclosan is a chlorophenol, a class of chemicals classified as a suspected animal carcinogen.
Clorophenols are also categorized as a persistent organic pollutant (POP), meaning that it can persist in the environment and bioaccumulate up the food chain.
I. Go to a local pharmacy or grocery store. Consider seven types of consumer products presented in Table PI O.I. Look at several brands and try to locate one that contains triclosan and/or nonylphenols.

Table P10.1
PRODUCT BRAND TRICLOSAN
(Yes/No)
NONYLPHENOL
(Yes/No) a. Using the product's label, how much information is provided on the ingredients? That is, can you tell what they are or their potential environmental or health risk? Is the information sufficient to make an informed decision (regarding environmental and personal safety) when purchasing the product? b.
Based on your above table, how common are these two compounds in consumer products (e.g., percent c.
O n
'
'
i-n
o
d.
Multiply these amounts by 12 and then by 293 million for a rough approximation of the total
U.S. consumption of these products per year. e.
f.
For each of these seven products, describe how they enter the surface water (step-by-step) during and after use. g.
Conduct an Internet or database search for news items containing the following terms: hormone mimicker, endocrine disrupt e rs, triclosan, and nonylphenol.
Report what you found.
Currently, there is little evidence to indicate that these two compounds present a direct, significant health or ecological risk. This, however, is because of a lack of data and the low levels observed in the environment. Although additional research may indicate that these compounds do not present an appreciable health threat, some advocate the adoption of the precautionary principle when dealing with widespread environmental contaminants. The precautionary principle, initiated in Europe in the 1970s and articulated in the Rio Declaration of the 1992 United Nations Conference on Environment and Development (Agenda 21), means to take prudent action when there is sufficient scientific evidence (but not necessarily absolute proof) that inaction could lead to harm and where action can be justified on reasonable judgments of cost-effectiveness (Foster et al.
2000). a.
What specific type of scientific evidence do you believe is necessary to support a ban?

b.
List and explain the various considerations policymakers would need to make in banning these two compounds. c.
List at least three other specific emerging environmental issues/problems in which we have scientificevidence, but have not yet acted to any appreciable degree. d.
Why have we failed to act in these cases? 3.
Assume there will be no ban on hormone mimickers in the near future . a. What consumer choices can you make that will likely reduce the potential impact on the environment? b. What other available information on a consumer product can help make environmentally informed choices?
Colborn, T, Dumanoski, D ., and ) .P. Myers.
1996. Our Stolen Future: Are We Threatening Our
Fertility, Intelligence, and Survival? Penguin Books, New York.
Daughton, C.G.
2003. Environmental Stewardship of Pharmaceuticals: The Green Pharmacy. IM
Proceedings of the 3rd International Conference on Pharmaceuticals and Endocrine Disrupting
Chemicals in Water, National Ground Water Association, 19-21 March 2003, Minneapolis, MN.
K.R., Vecchia,
M.H.
Repacholi.
Kolpin, D.W., Furlong, E.T., Meyer, M.T, Thurman, E.M., Zaugg, S.D., Barber, L.B., and H.T.
Buxton.
2002. Pharmaceuticals, Hormones, and Other Organic Wastewater Contaminants in U.S.
Streams, 1999-2000: A National Reconnaissance. Environmental Science and Technology
36:1202-1211.