The Challenge of Micropollutants
in Aquatic Systems
Rene´ P. Schwarzenbach,* Beate I. Escher, Kathrin Fenner, Thomas B. Hofstetter,
C. Annette Johnson, Urs von Gunten, Bernhard Wehrli
The increasing worldwide contamination of freshwater systems with thousands of industrial and
natural chemical compounds is one of the key environmental problems facing humanity. Although
most of these compounds are present at low concentrations, many of them raise considerable
toxicological concerns, particularly when present as components of complex mixtures. Here we
review three scientific challenges in addressing water-quality problems caused by such micropollutants.
First, tools to assess the impact of these pollutants on aquatic life and human health
must be further developed and refined. Second, cost-effective and appropriate remediation and
water-treatment technologies must be explored and implemented. Third, usage and disposal
strategies, coupled with the search for environmentally more benign products and processes,
should aim to minimize introduction of critical pollutants into the aquatic environment