Executive Summary
A fresh produce field is a complex and variable biological environment. The make-up of the soil, topography of the land, chemistry of the water used for irrigation, fertilizers used and the timing of those applications, the amount of sunlight and rainfall, wind and humidity, the physical structure of the crop and its genetic capabilities and physiological capacities to protect itself from viruses and bacteria, animal interactions, and the competing and supportive microorganisms that are present, all conspire to impact the persistence and movement of human pathogens in a field. Indeed, each of the research subject areas discussed in this report, up to this point, are more detailed accounts of the variables that impact pathogen persistence on the farm. Building on those important learnings, the research summarized here reinforces and deepens the industry knowledgebase on pathogen persistence and movement on the farm with these conclusions:
- Human pathogens can persist in field environments for extended periods of time.
- The field environment is a complex biological system and the interaction of pathogens with the variables in that system determines its persistence and die-off rates.
- Effective, verifiable cleaning and sanitation practices on harvest equipment and tools is critically important to control transference of pathogens to the product on the farm.
- Hand washing and proper use of gloves is a key deterrent to viral and bacterial pathogen transfer.
- Concentrated animal feeding operations (CAFOs), large poultry operations, and dairies are hazards. Wind-blown dust or bioaerosols emanating from animal operations can facilitate transference of pathogens to crops, soil, and open water sources representing a contamination risk.
- Flooding events can move pathogens onto and within farms.