Livestock farmers dispute research showing that dust from feedlots can contaminate irrigation water

A national trade group representing beef producers is opposing a research project that found feedlot dust can contaminate production fields and irrigation water.

The National Cattlemen’s Beef Association posted a statement saying more research is needed.

The setback came after the Food and Drug Association reported findings from a five-year research project conducted by the agency along with state and local entities and groups representing leafy vegetable growers. The project, which ran from 2019 to early this year, was launched after a deadly E. Coli outbreak in 2018 linked to romaine lettuce grown in Arizona.

The romaine cultivation fields were close to and sometimes adjacent to pasture lands with 80,000 cattle. Uncovered irrigation canals run through the area, which is located in the Arizona desert.

The livestock producers association cited a 2018 study that found E. Coli outbreaks in irrigation water, but did not find it specifically in pasture.

“Despite these 2018 study findings, we are concerned that some have misinterpreted the new FDA study as suggesting that the livestock industry is responsible for the outbreak, even though the scientific evidence does not support such a conclusion,” said Colin Woodall, CEO of NCBA.

“It’s clear that more scientific data is needed, but we shouldn’t allow ourselves to get ahead of the science and play the blame game.”

The five-year study included more than 15,000 tests collected in areas representing 12 percent of the irrigated growing area near Yuma, Arizona.

“. . . Air, water, and lettuce leaf microbiome analysis showed deposition of dust from livestock pens to nearby water and land, suggesting that dust from CAFOs (concentrated animal feeding operations) may play a role in STEC transmission in this part of the region. These findings indicate that STEC can survive in the air and that dust can act as a transfer mechanism for both pathogens and indicator organisms (e.g., generic E. coli) from adjacent and nearby land to water, soil, and plant tissue,” the report said.

During the five-year investigation, the FDA conducted a separate investigation into a 2020 leafy greens outbreak. Conclusions in the 2021 investigation report included: “We have released our information preliminary findings earlier this year, it was noted that this study identified the outbreak strain in a sample of cattle feces collected from the side of the road about a mile uphill from a farm. This finding refocused our attention on the role that livestock grazing on agricultural lands near green fields could have in increasing the risk of product contamination, where contamination could be spread by water, wind, or other means. Findings from investigations into foodborne illness outbreaks since 2013 indicate that proximity to livestock is likely a contributing factor to the contamination of leafy greens. Cattle have been repeatedly shown to be a persistent source of pathogenic E. coli, including E. coli O157:H7.”

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