The Issue

• Environmental Contamination by Drugs
• Preventing Harm from Pharmaceuticals

The huge quantities of medicines ending up in waste or in aquatic systems are a major environmental health issue. The increasing documentation of low-dose health effects makes pharmaceuticals a priority area from an environmental health perspective.

While patients should be allowed access to the best available pharmaceutical treatment, other things being equal, we should consider the medicine's PBT (persistence, bioaccumulation and toxicity) when developing, manufacturing, prescribing, purchasing, donating and disposing of medicines. Our collective aim should be to protect people and the environment from contamination of hazardous chemicals that wouldn't otherwise be there.

Health Care Without Harm provides resources to increase our understanding of the issues involving pharmaceuticals and suggests ways to reduce their environmental impact.

Environmental Contamination by Drugs

Where did all the vultures go?

Almost all the vultures in Asia have died — only 3% remain. In 2004, the culprit was discovered: vultures are highly sensitive to the non-steroidal anti-inflammatory diclofenac.

Exposure to a few miligrams is enough to cause catastrophic kidney failure
(see AVMA article).

"As few as one in 760 carcasses containing diclofenac at a dose lethal to vultures would be sufficient to cause the observed decline in vulture numbers (30% per year). Clearly, even small-scale usage of the drug can have catastrophic consequences." Birdlife International

Hundreds of different active pharmaceutical compounds are being discovered in waterways all over the world. Concern is increasing about the harm these might be doing to human health and the environment.

Although levels are usually too low to result in acute effects such as organ damage, there are two cases where drugs have had drastic effects: where the anti-inflammatory diclofenac has virtually wiped out the vulture population of Asia, while man-made estradiol has caused fish to start changing sex.

Although the levels of other drugs don't cause acute reactions, there is little or no information about the non-acute effects which low doses might have on wildlife and humans.

There are suggestions in research that contaminated water affects fish in subtle ways, such as changing breeding behaviour. This may cause declines in populations, or even be an indicator of other problems.

Ordinary risk assessment is of limited value in determining the environmental hazard posed by low levels of pharmaceutical compounds, as it only looks at acute effects, struggles to assess the potential effects of mixtures of compounds, and has no way to anticipate freak reactions.

What we do know is that pharmaceutical compounds are biologically active and they are detectable in our waterways. We can be sure that it would be better if they were not there. Therefore, we need to take steps to deal with the problem.

Preventing Harm from Pharmaceuticals

• Reduce the quantities of drugs
  prescribed; of those prescribed, choose the least environmentally-hazardous
• Take back unused drugs
  instead of flushing them down the toilet or putting them in the bin
• Improve wastewater treatment methods
• Design and develop green drugs,
  which rapidly biodegrade in the environment into harmless compounds