Ecotoxicology Risk Assessment for a Changing World
Exponential economic growth has resulted in grave damage to the biospheric life support system and the ecosystems that comprise it. The ubiquitous single-species toxicity tests providecrucial evidence on death, reproductive processes, and recruitment rates, but not on important ecosystem attributes such as community structure and function. The testing systems used (microcosms, mesocosms, and field enclosures) are not miniature ecosystems but can, if appropriately designed, furnish useful information on the risk of toxicants to important cause/ effect pathways. Ecosystems provide important resources and services upon which humankind depends, so they deserve more protection than they are now getting. Ecotoxicology is based on the use of endpoints (e.g., nutrient cycling, energy transfer) characteristic of ecosystems. Economic globalization has resulted in a marked increase in waste discharges in developing countries. Developed countries must help train ecotoxicologists in developing countries so that problems can be treated at the source where total societal costs are lowest. Developed countries must also avoid creating technologies that are inappropriate everywhere lest they be adopted by developing countries (e.g., _seeding the oceans with iron). In addition, very rapid climate change provides many challenges to ecotoxicologists. Even small (2-3 C) increases in temperature may alter partitioning and uptake of many chemical substances. As the tropical zone moves both north and south, test species will change, as will the ecosystems they inhabit. Toxicity testing methods and procedures must be modified as rapidly as these ecological changes occur. Developing and obtaining approval for new ecotoxicity testing methods (e.g., American Society for Testing and Materials or European Union) will be a necessary but time consuming activity. The information flow is inadequate between bottom-up (i.e., ecosystem component information and top-down (i.e., system level) information. Yet a synthesis of the two types of information is essential for sound decision making. All components of the biosphere (e.g., air, water, land, biota) are important to systems (e.g., Gaia), but are all too often considered in isolation from each other. All too often, disciplines, even ecotoxicology, are too isolated from each other and the general public. The attacks on global climate change science and evolution in the United States are good examples of the consequences of this discontinuity. In addition, ecotoxicologists need to become more involved in the developing field of nanotechnology.