文档介绍：III. EXPOSURE ASSESSMENT
III. EXPOSURE ASSESSMENT
Exposure to foodborne L. monocytogenes can be described in two primary ways. The first is by
characterizing the range of likely pathways by which foods e contaminated with L.
monocytogenes. The second addresses the likely consumption levels of the contaminated food.
Unlike other pleted microbiological risk assessments, this risk assessment does not
consider the contamination pathway or the effects of preventive interventions and controls on the
likely consumption levels. Two exceptions are efforts to model growth during refrigeration and
thermal destruction during home cooking or reheating. Because the goal of this risk assessment was
to provide information needed to focus risk management strategies among a variety of foods that
could be potentially contaminated with L. monocytogenes, the emphasis of the exposure assessment
for this risk assessment is to model the consumption of foods that have a potential for L.
monocytogenes contamination.
Exposure is a function of the amount of a food consumed and the level of contamination in that food.
Hence, it was necessary to develop estimates of the quantity of contaminated foods likely to be
consumed in the U. S., as well as the L. monocytogenes levels in those foods. However, limitations
inherent in food consumption data and the paucity of contamination data for certain foods made
certain assumptions necessary to develop the estimates. These limitations and assumptions are
discussed later in this document.
Foods that were included in the risk assessment were identified either through prehensive
review of the recall, microbiological and epidemiological literature. Each food was placed in one of
20 food categories. Using distributions of contamination and consumption data, estimates of
exposure to L. monocytogenes in the various foods were derived.
Food Category Identification
The first step in the exposure assessment was to consider appropriate foo