Quantitative microbial risk assessment of waterborne pathogens: History and progress

Environmental risk assessment, an emerging field established in the 1970s, provides scientific basis for environment risk management decision making. The development of environmental risk assessment has been through three stages: accident risk assessment, health risk assessment, ecological risk assessment. Accident risk assessment evaluates the risks originated from unforeseen events or accidents. Health risk assessment explores the human health impact of chemicals. Ecological risk assessment investigates ecosystem risks due to various factors. Quantitative Microbial Risk Assessment (QMRA) firstly proposed in the 1990s, is focused on microbial contamination as risk source and human health as risk receptor. QMRA describes mathematical relations between intake of microorganism and the probability that it results in infection, illness, or death within a population. QMRA is a leading microbial health risk assessment approach, providing sound scientific basis for public health policies and standards as well as feasible health intervention decision-making. It has been applied to environmental management worldwide, such as the U.S., Canada, Netherlands, Australia, and so on. The present study summarizes the history of QMRA and provides vision of the future of QMRA. Meanwhile, the challenges and issues of QMRA research and applications in China are discussed and suggestions to facilitate QMRA development are provided, aiming to improve risk management related with waterborne microbial contamination in China.