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Unit 6: Risk, Exposure, and Health // Section 9: The Precautionary Principle

Under the basic risk analysis model, regulators quantify risks and compare the costs and benefits of various control options before they set limits on hazards. However, over the past several decades some governments have formally adopted a different approach called the Precautionary Principle as a guideline. This view holds that governments should not wait to limit contaminants in food, water, air, or commercial products until scientific studies have reduced uncertainties about exposure and effects.

Although the idea of "better safe than sorry" can be traced as far back in history as the Hippocratic Oath, the Precautionary Principle was first codified as an approach to environmental protection in West German national policies of the 1970s. References to a precautionary approach began to appear in international agreements in the 1980s and 1990s. The Wingspread Statement, a declaration drafted by government officials, attorneys, and labor and environmental advocates at an international conference in 1998, argued that existing environmental regulations (especially those based on risk assessment) did not protect human health and the environment well enough and that a new approach was required. "When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically. In this context the proponent of an activity, rather than the public, should bear the burden of proof," the statement asserted.

The Precautionary Principle has taken root most strongly in the European Union (EU). In 2000 the EU issued a communiqué stating that the principle applied "where scientific evidence is insufficient, inconclusive, or uncertain and preliminary scientific evidence indicates that there are reasonable grounds for concern that the potentially dangerous effects on the environment, human, animal, or plant health may be inconsistent with the high level of protection chosen by the EU." European regulators have invoked the Precautionary Principle to support steps such as banning imported beef treated with hormones and adopting the Restriction of Hazardous Substances Directive, which requires electronics manufacturers to remove lead, mercury, cadmium, and other hazardous substances from most of their products (Fig. 15).

Label indicating that a product complies with the EU's Restrictions of Hazardous Substances (RoHS) directive

Figure 15. Label indicating that a product complies with the EU's Restrictions of Hazardous Substances (RoHS) directive
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Source: 2007. Image-Tek/

The Precautionary Principle plays a much weaker role in U.S. environmental regulation, which generally assumes that some level of risk from exposure to contaminants is acceptable and sets controls intended to limit pollution to those levels. Unlike the EU, the United States does not require comprehensive product testing or labeling.

However, some U.S. laws take a precautionary approach in more limited areas. For example, new drugs must be tested before they can be sold, and the National Environmental Policy Act requires environmental impact assessments for any major projects that are federally funded, with an obligation to consider alternatives including no action. Some states and cities have adopted regulations that take a precautionary approach to policies such as using pesticides in schools or funding new technologies. For the most part, though, U.S. environmental laws require some scientific proof of harm as a basis for protective action.

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