Mildly Caffeinated

May 2008

Lake Champlain is “mildly caffeinated”. That was the summary of Pat Phillips, a researcher for the U.S. Geological Survey who spent five months looking for the presence of various chemicals in the lake. The chemicals, collectively referred to as new generation pollutants or emerging contaminants, included pharmaceuticals, fragrances, pesticides, and a wide variety of other by-products of modern life. Little is known about their individual effects on the environment and less about their additive effect. Phillips was just trying to discover if they were even present.

Attention to new generation pollutants really increased after the 2002 publication of a survey of waterbodies across the United States that found 80% had some form of contamination. Subsequent work has focused on areas with substantial discharges from wastewater treatment facilities. 

Phillips and his team took samples from a variety of different locations. These included waste water treatment facilities, combined sewer overflows, urban streams, large rivers, one undeveloped stream, and the lake itself. The highest concentrations of new generation pollutants were found in wastewater treatment effluent and combined sewer overflows, though concentrations in urban stormwater were frequently elevated as well. The only place where no pollutants were found was the undeveloped stream under normal flows. 

Few contaminants were found in Lake Champlain, but the three new generation contaminants found at the highest concentrations were caffeine, HHCB (a musk fragrance), and metolachlor (an herbicide). In-lake concentrations appear to be quite low, and there is little indication at this time of significant ecological effects. Active pharmaceuticals were not found in the lake or large streams, though they were detected in at least one sample from the wastewater treatment facility effluent. Three compounds, codeine (a pain-killer), diphenydramine (Benadryl – an antihistamine), and carbamazapine (an anticonvulsant), were detected in every wastewater effluent sample. The compound with the highest single sample concentration was acetaminophen. In addition to the other pharmaceuticals, tests for eight anti-microbial compounds were conducted. Tests at the Burlington Riverside wastewater treatment facility, which receives waste from a large hospital, detected five of the eight.

The most worrisome of the new generation contaminants have the ability to mimic growth and sex hormones, perhaps even at low concentrations. For example, bisphenol-a, a compound commonly found in many plastics including food and beverage packaging, has been in the news lately. The U.S. National Toxicology Program has recently expressed concern about health effects to fetuses, infants, and children even at levels to which people are currently exposed. This finding led the company Nalgene, maker of many water bottles, to announce recently that they would phase out use of bisphenol-a in its products. Bisphenol-a was not detected in Phillips’ water samples.

In other areas around the country the ecological effects of hormone mimics have been quite shocking. In Texas, bluegill had measurable concentrations of the active ingredient from Prozac, an anti-depressant. Male fish have been found to produce eggs throughout the Potomac River watershed in Virginia, West Virginia, Maryland, and the District of Columbia. Outside Denver, Colorado the reproductive organs of some fish were so mixed up researchers could not identify whether they were male or female. In the oceans off of Los Angeles male fish had ovary tissue in their testes. Outside Las Vegas three different species of fish had marked decreases in the amount and quality of their sperm. Even in an agricultural watershed in Nebraska, male minnows had one-third less testosterone while females had 20% less estrogen and 45% more testosterone downstream from a large animal feed lot where hormones were used to treat cattle compared to upstream. It has not been possible to link the effects seen in the wild to any particular chemical but a number of suspects have been identified.

Substances from our medicine cabinets can follow at least two pathways to the wastewater treatment facility. Some are not metabolized by our body and may still be active after they are excreted. Alternatively, their presence in wastewater can result from people flushing leftover pills down the toilet. The Lake Champlain Committee recommends disposing of unused medications by throwing them in the trash. Ideally, the medications should be disposed of in their original container after being made unusable either by adding a little water to solids or adding coffee grounds or kitty litter to liquids.