Risk Assessment


This topic was moderated by Kuen-Yuh Wu, Ph.D. and Kuan Chen Cheng, Ph.D. and included four lectures.


Deog-Hwan Oh, Ph.D., Professor, Department of Food & Biotechnology, Kangwon National University, Korea discussed microbiological risk assessments of food-borne disease in ready-to-eat foods in Korea. Dr. Oh shared that in Korea, many outbreaks of foodborne disease have been attributed to consumption of ready-to-eat (RTE) foods such as kimchi, lettuce, ham, and sausage. Microbiological risk assessment (MRA) can be used as a powerful tool to evaluate microbiological risks associated with foodborne microbiological hazards. Based on MRA principles and guidelines provided by Codex Alimentarius Commission, in 2007 the Korean Food and Drug Administration (KFDA) established the Guidance for Risk Assessment Methods and Procedures. Utilizing these guidelines, with sufficient input settings, a full MRA including hazard identification, hazard characterization, exposure assessment and risk characterization can be carried out.


Dr. George Pugh, Ph.D., Director, Scientific and Regulatory Affairs, The Coca-Cola Company, USA discussed applying general principles of risk assessment to food safety. Dr. Pugh noted that risk assessment process is very important for providing risk managers such as government regulatory officials with a rational basis for decisionmaking regarding chemical use in the context of human health protection. Dr. Pugh explored best practices for conducting food safety evaluations and the data required for food safety evaluations.


Shiowshuh Sheen, Ph.D., Senior Scientist, Eastern Regional Research Center, ARS, USDA, USA discussed food-borne pathogen growth and survival modeling for risk assessment. Dr. Sheen discussed that though generally microbial growth and inactivation can be described using the first-order kinetic models, microbes’ responses to dynamic environment are complex and difficult to predict due to multiple growth and survival factors. Dr. Sheen outlined that microbial modeling typically involves empirical, semi-empirical, or theoretical methods, and discussed how Pathogen Modeling Program (PMP and integrated-PMP) established by USDA and ComBase are two useful tools (free of charge and accessible by computer to any end-users) to predict food-borne pathogen growth and inactivation in a variety of foods.


Kuen-Yuh Yu, Ph.D., Professor, Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University, Taiwan gave a lecture titled, “Probabilistic Risk Assessment by Using Bayesian Statistics-Markov Chain Monte Carlo Simulation.”


Dr. Yu discussed the frequency with which risk assessors encounter insufficient data to fit distributions for some parameters, especially concentrations and intake rates, and the ways in which incomplete data can hinder the completion of an assessment. In order to reduce uncertainty due to insufficient data, the Bayesian statistics Markov chain Monte Carlo (MCMC) simulation can be applied to perform probabilistic risk assessments (PRA). Dr. Yu presented four examples: assessment of lifetime cancer risk for N-nitrosodimethylamine (NDMA) in drinking water (only one sample with detectable NDMA level out of 50 samples collected); assessment of lifetime cancer risk for aflatoxin B1 in food (only few data greater than regulations were available); assessment of health risk for medical staffs exposed to cisplatin by using urinary platinum as biomarker to reconstruct exposures; and assessment of lifetime cancer risk for acrylamide in high-temperature processed foods with high uncertainty in residue and intake rate data.