Environmental Science & Engineering - www.esemag.com - March 2003
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When pharmaceuticals arrive at the tap

The new issue emerging in environmental science is the contamination of ground and surface water bodies with pharmaceutical and personal care products, or PPCPs.

When people take medications, or use personal care products such as medicated shampoo or sunscreen, a considerable amount of the biologically active chemical eventually enters the wastewater stream after passing through, or flowing off the body. The same holds true for veterinary medicines and animal care products. PPCPs have been found in studies of ground and surface waters in Canada, Germany, and the United States, and can be expected to appear in most developed areas.

In Canada, surface waters near wastewater treatment plants were found contaminated with painkillers, anti-inflammatory drugs, anti-seizure medications, and blood cholesterol drugs (Stevenson, 2002). Drugs found in German rivers include carbamazepine, an anti-convulsant, and diclofenac, an anti-inflammatory, at concentrations up to 1 part per billion (Potera, 2000). Under landfills, where water leaching downward can carry drugs along with it, far higher concentrations have been found, posing a risk to nearby sub-surface waters. In the United States, attention has also focused on animal feed lots, where animal wastes, contaminated with antibiotics, have led to contamination of local surface waters (Kolpin et al., 2002).

Around the world, more than 60 chemicals have been discovered in water sources, including anti-cancer medications, anti-asthma medications, anti-cholesterol drugs, hypnotics, antibiotics, antiseptics, X-ray contrast agents, sunscreen agents, caffeine, and synthetic musk fragrance chemicals (Potera, 2002).

The most troubling findings in the growing body of PPCP research is that some of these drugs are making it into fresh water systems, and are detectable at the tap. In a study by Glen Boyd at Tulane University, for example, several PPCPs were detected in local tap water samples including the pain killer naproxen, the sex hormone estrone, and a breakdown product of anti-cholesterol drugs (Potera, 2000). Though the chemicals were found at very low levels - they were barely detectable - scientists consider them of concern because, by design, pharmaceuticals are intended to exert their effects at very low concentrations.

In response to the growing concern, in September, 2001, Health Canada enacted a two-year program to study new environmental assessment regulations for PPCPs. And as of September 13, 2001, companies seeking approval to import or manufacture new products regulated under Canada’s Food and Drugs Act have to notify the Minister of the Environment under the New Substances Notification Regulations of the Canadian Environmental Protection Act (Health Canada, 2001).

Health Canada’s two-year research project is half over, and calls for concrete regulatory action are likely as advocates of the precautionary principle team up with planners of the "we must act even in uncertainty" mindset. But like other low-concentration, poorly understood environmental contamination issues, managing the risk of PPCPs poses several challenges, that, if not handled carefully, could ultimately result in less safety and less environmental quality for Canadians.

Policy challenges PPCPs pose several policy challenges common to managing uncertain, low-level environmental risks.

First, there is the challenge of determining whether or not PPCPs actually pose a risk to plant, animal, or human health. Though unpleasant to contemplate, all of Earth’s organisms evolved and spend their lives being exposed to very low concentrations of thousands of potentially harmful chemicals, both natural and artificial. Preventing all such exposures would be impossible, even if society had unlimited resources to throw at the problem. Thus, one question that must be answered with PPCPs is: "Does the dose make a poison?" On this front, expert opinion suggests that the dosages are too low to be considered risky, but some theories suggest that even very low exposure levels could ultimately cause harm, particularly for pharmaceuticals (Stevenson, 2002).

Second, there is the challenge of addressing newly discovered, still uncertain, and probably low-level risks without shifting resources away from the management of older, bigger, better established risks. As public health researchers at Harvard University have shown, there is a real cost to be paid when management of lower-level, more uncertain risk is allowed to consume resources that could be used to address higher-level, more certain risks. As researchers Tammy Tengs and John D. Graham observe, the United States spent about $21.4 (US) billion in 1994 on 185 life-saving interventions, averting about 57,000 deaths. But spending that same amount of money, prioritized to produce maximum return on investment, would have saved an additional 60,000 people (Tengs and Graham, 1996).

And one cannot forget that the single biggest protector of safety, health, and environmental quality is societal and individual wealth (Bloom and Canning, 2000). Resources taken out of the productive economy and shifted into the regulatory economy are not risk-neutral. Indeed, by reducing economic growth, regulatory diversion of resources constitutes a risk-increasing factor that may offset the perceived benefit of regulating a low-level risk such as PPCP exposure.

Third, there is the challenge of figuring out the proper point at which the problem can best be managed. Without eliminating the use of pharmaceuticals and chemicals altogether, one cannot prevent the release of PPCPs into the environment through the diverse set of waste streams discussed above. That means that management of PPCP contamination and exposure has to be handled downstream, at the point of drinking water and wastewater treatment.

But even that would only be a partial solution as water treatment does not account for PPCPs that find their way into surface and subsurface sources through landfill leaching, animal feedlots, or pet wastes, which contain veterinary PPCPs with similar characteristics to PPCPs of human origin. Water purification at the point of consumption could remove PPCPs from the tap entirely, but this would not address potential impacts of PPCPs on wildlife, or on people who periodically consume the wildlife, such as hunters or fishers.

Additionally, one could envision a system in which all unused PPCPs were returned to pharmacies, which would ensure their environmentally safe disposal, but such a system would also address only a small fraction of the problem.

All of these approaches would address only a portion of the sources of PPCP contamination, but each would impose significant costs, draining resources away from the health-protective productive economy. Which takes us to the last question: Who should pay for PPCP management?

Ideally, to create the right incentives for reducing pollution, the cost of remediation should rest on the polluter, but this straightforward approach has problems. Under this principle, consumers would be responsible for the added costs of downstream waste water remediation, and the costs allocated according to use, perhaps collected as a fee attached to drugs and personal care products. But this is problematic in terms of ability to pay, and fundamental ethics.

The basic ethic of the "polluter pays" principle presumes that the polluter has a meaningful ability to change his or her behavior in response to the incentives, which is unlikely in the case of many medicines. Shifting the fee up the ladder of production to the producers of PPCPs wouldn’t really circumvent this dilemma, as such costs will ultimately be passed onto the already cost-burdened pharmaceutical user as well, or, in the case of insured pharmaceuticals, onto the general taxpayer.

The costs of additional drinking water or wastewater purification would ultimately be paid by consumers, but this diffuse cost recovery would not give incentives to some of the larger PPCP releasers (landfills and feedlots) to institute technological controls that might prevent the entry of PPCPs into the environment.

Conclusion PPCPs are a newly-discovered form of pollution that poses several difficult challenges to policymakers, but one is paramount: while the risk is known to be low-level and is still highly uncertain, remedies have known drawbacks that can easily make the public, or subpopulations, less well off. Such drawbacks include the potential for diverting resources from more certain risks of higher magnitudes, or for reducing after-tax income of the general population, or already-cash-strapped subpopulations, a phenomenon that clearly puts those populations at greater risk from a broad range of adverse health consequences. Individuals who are highly risk-averse might choose to limit water intake to only purified sources, but this addresses only a small part of the overall policy challenge.

Policymakers are likely to be pressured to act to somehow ensure that PPCPs do not cause environmental harm, or pose a hazard to the health of even sensitive individuals in the population.

But in circumstances such as these, where risks are poorly defined and interventions likely to be costly and only marginally effective, policymakers would do well to consider the work of policy analyst Aaron Wildavsky, who showed that such high-uncertainty/ low-level risk situations lend themselves to watchfulness and research, but not interceptive action (Wildavsky, 1991). They should pay particular attention to the work of Harvard’s Tammy Tengs and John Graham, who point out that prioritization is key to maximizing public safety (Tengs and Graham, 1996). And they should study the work of toxicologist Bruce Ames and others who point out that truly, it’s the dose that makes the poison (Ames and Gold, 1998). Scrutiny of the work of these well-respected students of health, safety, and environmental quality would suggest that at present, the best response to the PPCP situation, as with many other environmental problems, is to watch and wait until one can see the whites of its eyes.

Kenneth Green, D. Env. (keng@fraserinstitute.ca) is Chief Scientist and Director of the Centre for Studies in Risk, Regulation and Environment at The Fraser Institute. He most recently wrote Global Warming: Understanding the Debate. This article first appeared in Fraser Forum (www.fraserinstitute.ca) and is reprinted here with permission.

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