Scientific foundation of regulating ionizing radiation: application of metrics for evaluation of regulatory science information

Regulating Ionizing Radiation Based on Metrics for Evaluation of Regulatory Science Claims

This article attempts to reconcile differences within the relevant scientific community on the effect of exposure to low levels of ionizing radiation notably the applicability of linear nonthreshold (LNT) process at exposures below a certain limit. This article applies an updated version of Metrics for Evaluation of Regulatory Science Claims (MERSC) derived form Best Available Regulatory Science (BARS) to the arguments provided by the proponents and opponents of LNT. Based on BARS/MERSC, 3 categories of effects of exposure to ionizing radiation are identified. One category (designated as S) consists of reproducible and undisputed adverse effects. A second category (designated as U) consists of areas where the scientific evidence for potential adverse effects includes uncertainties. The scientific evidence in the U category leads to a threshold. In contrast, the scientific foundation of the third category (designated as P) is questionable, as the scientific evidence indicates that adverse effects of the exposure at this level are not only questionable but may be helpful. This article claims that the third area is the domain of policy makers including regulators. This article describes Jeffersonian Principle that categorizes the affected community into specialists, knowledgeable nonspecialists, and the general public. Based on Jeffersonian Principle, the relevant scientific information, particularly the U and P areas, must be translated into a language that at a minimum is understandable to the knowledgeable group. Once this process is completed, the policy makers including regulators may select exposure limits based on their judgment.

Golden rice: scientific, regulatory and public information processes of a genetically modified organism

Historically, agricultural development evolved in three phases. During the first phase the plants were selected on the basis of the availability of a plant with desirable properties at a specific location. The second phase provided the agricultural community with crossbreeding plants to achieve improvement in agricultural production. The evolution of biological knowledge has provided the ability to genetically engineer (GE) crops, one of the key processes within genetically modified organisms (GMO). This article uses golden rice, a species of transgenic Asian rice which contains a precursor of vitamin A in the edible part of the plant as an example of GE/GMO emphasizing Chinese experience in agricultural evolution. It includes a brief review of agricultural evolution to be followed by a description of golden rice development. Golden rice was created as a humanitarian project and has received positive comments by the scientific community and negative voices from certain environmental groups. In this article, we use the Best Available Science (BAS) Concept and Metrics for Evaluation of Scientific Claims (MESC) derived from it to evaluate claims and counter claims on scientific aspects of golden rice. This article concludes that opposition to golden rice is based on belief rather than any of its scientifically derived nutritional, safety or environmental properties.