Home » Microbiological Risk Assessment: Origins, Current Status, and Future Challenges
The process for evaluating chemicals in foods and the environment advanced significantly in 1983 when the National Research Council (NRC) published the first edition of its publication Risk Assessment in the Federal Government: Managing the Process. This publication, which became known as “The Red Book,” detailed a risk assessment approach to making decisions related to the safety of potentially toxic chemicals based on a four-step process consisting of hazard identification, dose response assessment, exposure analysis, and characterization of risks.1 The process has continued to evolve as both the toxicology and risk assessment methods have become increasingly sophisticated, and the approach has been adopted internationally by national governments and intergovernmental food standards organizations such as Codex Alimentarius Commission (CAC). In 1994, CAC requested that the UN Food and Agriculture Organization (FAO) and the World Health Organization (WHO) convene an “Expert Consultation on the Application of Risk Analysis to Food Standards Issues.”2 The scope of the consultation included chemical compounds such as food additives, naturally occurring toxins, mycotoxins, and marine biotoxins. The consultation also evaluated the use of risk analysis for pathogenic biological agents such as bacteria, viruses, helminths, and protozoa. The report provided specific recommendations related to chemicals that were in keeping with the protocols in the NRC Red Book and provided a procedural framework to accommodate the globalization of the process for development of Codex Alimentarius standards.2 The recommendations for biological agents acknowledged the need for a similar framework but indicated that the complex behavior of biological agents made it unlikely that a fully quantitative risk analysis approach could be achieved in the near term. However, the report fully recommended the investment in developing such capabilities.
Realization of the WHO/FAO expert consultation’s recommendations came about much more quickly than anticipated, with the first examples of quantitative microbiological risk assessment modeling applied to water and seafood appearing in the early 1990s,3 and by the mid-1990s, quantitative consideration of microbiological risks associated with foods began to be published.4 Several factors encouraged the rapid advancement. One of the key factors was the signing of the World Trade Organization (WTO) “Agreement on Sanitary and Phytosanitary Measures,” which was finalized in 1994 and implemented in 1995. The agreement includes specific statements that (1) require the use of risk assessment as a tool when the WTO arbitrates sanitary and phytosanitary (SPS)-related trade disputes, and (2) identified the CAC as the international standards-setting body for SPS issues related to food. As mentioned above, the CAC had already adopted a risk assessment approach for toxic chemicals but did not have a similar program for microbiological hazards. This stimulated the national governments of most developed countries to begin to develop risk assessment approaches for microbiological food safety standards. At the same time, national governments began to require formal risk assessments for the development of new regulations. For example, in the United States, the U.S. Department of Agriculture (USDA) Reorganization Act of 1994 required a formal risk assessment be conducted for any proposed major regulation that included public health or environmental concerns. In subsequent years, this was expanded to other government regulatory agencies, making conducting risk assessments as a requirement when proposing a new regulation. The two other factors that came together at that time were more technical in nature. During the late 1980s and the early 1990s, there was an international effort to develop mathematical models of microbial growth, survival, and inactivation. While this effort, which was ultimately coined “predictive microbiology,” began much earlier in developing models for thermal inactivation, the work during the 1990s included a large variety of foodborne pathogens and was developed in a manner that could be applied to a wide range of foods. Early in this process, it was recognized that such tools were a key to the development of quantitative microbial risk assessment.4–7 The final factor was the amazing advancements in computational tools that gave microbiologists, food scientists, and public health researchers the ability to develop complex stochastic risk assessment models.