Monday, July 19, 2010

Pharmaceuticals & Personal Care Products in Drinking Water:
Part 1

Intro

Pharmaceuticals, personal care products, endocrine disruptors, emerging contaminants – all of these terms have been in the news frequently in relation to drinking water, getting tossed around like a soccer ball at the World Cup. But what are they, what do they mean to the average person, and should anyone be overly concerned about them? Let’s take a look at the issue and see.

The Jargon

Endocrine Disrupting Compounds (EDC’s) – These compounds are anything that can interfere with the endocrine, or hormonal systems, of living creatures. Primarily, we are talking about vertebrates, especially people. Compounds in this class include things that we have known about for a long time, like nitrate or atrazine; or chemicals that have been more recently discovered in drinking water sources, such as estradiol or bisphenol A.

Pharmaceuticals & Personal Care Products (PPCP’s) – These obviously include pharmaceutical compounds, like carbamazepine (to control seizures) and fluoxetine, also known as Prozac, which is very commonly found in many water sources; I guess we really are a Prozac Nation (Elizabeth Wurtzel, Riverhead Trade, 1994). Personal Care Products include the literally thousands of compounds found in the products we all use every day, like tooth paste, deodorant, shampoo, and shave cream; and include chemicals that are fragrances, surfactants, disinfectants, coloring agents, preservatives, etc.

Compounds of Emerging Concern (CEC’s) – These are any of a host of chemical compounds not currently regulated, for which little if any toxicological data exists, but which cause concern because of their presence in drinking water sources and in drinking water itself.

If this isn’t confusing enough, many EDC’s and PPCP’s are CEC’s, but not all; PPCP’s can be EDC’s, and vice versa, but not necessarily; and not all CEC’s are PPCP’s or EDC’s. It’s an alphabet soup of acronyms referring to literally thousands of compounds that cause confusion among water professionals and the public alike.

Where are they and how do they get there?

All of these compounds can be found to one degree or another almost everywhere you look:
  • Found in Surface Waters
    • Lakes, streams, ponds
    • Urban and rural areas
  • Found in Groundwaters
    • Wells
  • Found in Finished Water
    • Drinking water plant effluent
    • Drinking water in the distribution system
  • Found in effluent from wastewater treatment plants
    • Water discharged to the environment
    • Water for reuse and recycle projects

These compounds get into the environment from a whole host of sources. The pharmaceuticals taken by people are partially excreted in their urine, which passes through wastewater treatment plants unaffected and wind up in the environment. Hospitals dispose of tons of pharmaceuticals annually, either by dumping them in the sewers or land filling them, where they may potentially leach into the environment. Personal care products are used by all of us every day in fairly large quantities, all of which end up going down the drain, into the waste stream, and out into the environment. These compounds also come from manufacturing facilities, concentrated animal feeding operations (CAFO’s), and agricultural and urban runoff. "The Environmental Life Cycle of Pharmaceuticals ," a diagram by C.G. Daughton of the EPA’s National Exposure and Research Lab in Las Vegas, does a great job of showing the complexities of this issue.


"The Environmental Life Cycle of Pharmaceuticals ," by C.G. Daughton [illustration published in: Daughton, C.G. "Pharmaceuticals as Environmental Pollutants: the Ramifications for Human Exposure," In:
International Encyclopedia of Public Health, Kris Heggenhougen and Stella Quah (Eds.), Vol. 5, San Diego: Academic Press; 2008, pp. 66-102]


The pathways for other PPCP’s and EDC’s into the environment are no less complex. Having said all that, the large majority of these compounds are found at extremely low levels. Analytical results in the range of nanograms per litre (ng/L), or parts per trillion (ppt), are common. To give that some perspective, here’s some comparisons of what a part per trillion means:
  • One inch in 1.6 million miles
  • One second in 32,000 years
  • One cent in $10 billion
  • One square foot of the state of Indiana
  • One drop in 20 Olympic swimming pools
As you can see, a part per trillion isn’t much, but is it significant? We’ll talk about that in the next post.

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