AN UPDATE ON THE PRODUCE SAFETY RULE By Melissa Partyka
I
18
fresh produce have increased, so too has public awareness of produce production environments, placing irrigation supplies in the crosshairs. The microbial quality of irrigation water supplies is at the heart of the matter. Most bacterial, protozoal, and viral pathogens that have been associated with foodborne outbreaks are readily dispersed via water, so surface water distribution networks can spread localized sources of pathogens across large areas. If a grower’s irrigation source is contaminated, pathogens may be broadcast throughout a field, creating contact with many pieces of produce, and eventually resulting in an outbreak. These, among other qualities, make water a perfect vehicle for pathogens, making their regular monitoring beyond a good idea, but a necessity. The problem is deciding what to monitor for, which forces the underlying question: What makes people sick? The answer is: Many things! However, pathogens are relatively rare, and monitoring for a rare thing is not only time consuming but also expensive. So many agencies choose to monitor for indicator organisms that occur in high concentrations inside human and animal guts. To protect the public, standards are frequently set at concentrations associated with human illness. For example, the standards in the AWP come from the U.S. Environmental Protection Agency and state that approximately 36 in 1,000 people exposed to water with an average generic E. coli concentration of 126 colonyforming units/100 milliliters are likely to become ill. It does not say guaranteed, nor does it say ill with what. This estimation is the result of decades of research and is still IRRIGATION LEADER
PHOTOS COURTESY OF FLICKR/U.S. FOOD AND DRUG ADMINISTRATION AND MELISSA PARTYKA.
n November 2016, the U.S. Food and Drug Administration (FDA) finalized the Produce Safety Rule, which includes an Agricultural Water Provision (AWP) requiring that growers identify, inspect, and monitor their irrigation water supplies for indicator E. coli. Compliance for all aspects of the rule was set to begin in January 2018. However, in March 2017 the FDA made an announcement that it was reviewing the AWP after increasing pushback and confusion over some of the finer points of the provision. In the end, it kept the criteria the same but pushed the timeline for compliance out an additional 4 years and continued to emphasize the possibility of refinement as more science becomes available. Therein lies the rub. Most people recognize that monitoring the water supplies that come into direct contact with fresh produce is a good idea. The problem that the FDA has encountered, one echoed by the scientific community, is that there are currently not enough data available to create a truly science-based standard for irrigation water. That does not mean that the regulation of water has no basis in science, but rather that the science of irrigation water has lagged behind that of other water types, like drinking or swimming. Why is that? Because research is hard and expensive and takes a considerable amount of time before concrete answers may be had, if any ever are. Further, funding for research is frequently driven by demand, and until recently, the demand for research linking microbial contamination of irrigation water supplies to the risk of human illness in the United States has been low. However, as outbreaks of illness associated with consumption of
