A University of Illinois study catalogues and
analyzes these incidents as part of a larger effort towards greater
food safety and quality improvements in the fresh produce industry.
“There’s a big food safety concern about any wildlife that gets into
fields where fresh produce is grown, leading to various control
measures, sometimes even drastic tactics,” says Daniel Hughes,
postdoctoral researcher in the Department of Animal Sciences at U of
I and lead author on the study. “We’re trying to find non-lethal
solutions to exclude frogs from fields, but I realized even if we
implement new technologies, how do we know we solved anything?”
Hughes is referring to the fact that there is no publicly accessible
data documenting how often wildlife gets into fields and onto dinner
plates, and therefore no benchmarks to measure success of new
control measures. So, he started scouring the internet for media
mentions.
“I started looking out of curiosity, saving links to articles of
people finding frogs in their salads. Within a couple months, I had
this long list. I realized there’s something more going on here that
we’ve been led to believe. Every article I clicked on claimed it was
super rare, but when you’re looking at 25 of those incidents, it
doesn’t sound that rare to me,” he says.
Hughes decided to formalize his search using social science
standards and wound up with 40 news stories from the United States
between 2003 and 2018. He believes this sample strongly
underestimates the true scope of the issue. For example, consumers
may report incidents directly to the store or produce company and
not to media, or stories may have appeared in print versions of
newspapers and not been published online. Despite these
shortcomings, Hughes’ efforts represent the first systematic
analysis of available information on the issue.
Over 50% of the 40 incidents involved frogs, but lizards, snakes,
mice, birds, and yes, a bat, were found in salad greens, green
beans, or mixed vegetables. Ten of these – nine frogs and one lizard
– were found alive.
In three-quarters of the incidents, the produce was conventionally
grown, not organic.
“It was implied over and over in these articles: if you buy organic,
getting a frog is par for the course, essentially,” Hughes says. “If
that was true, we should have seen the opposite of what we found. We
did not take into account market-share differences between
conventional and organic produce, but this result ran contrary to
common opinion.”
Ultimately, Hughes was hoping the media reports would
suggest whether the presence of these animals in produce constitutes
a true food safety crisis, or simply a food quality issue. The
reports were inconclusive on that point, although the incidents were
not directly linked to outbreaks of foodborne illness. Only the bat
incident led to a recall, while most others led to apologies or
offers to replace the product or refund customers. [to top of second
column] |
Hughes thinks preventing animals from getting into the fields in
the first place is the industry’s best bet. Currently, many operations achieve
that by destroying non-crop vegetation near fields using so-called “scorched
earth” tactics, which seem to have been implemented in response to major E. coli
epidemics, such as the feral-pig-vectored spinach outbreak in 2006. This
approach likely goes too far for wild frogs because previous research has shown
they don’t harbor E. coli in the form or quantity usually responsible for
foodborne illnesses.
With more information about when and where wildlife is getting into produce,
farmers could adopt less drastic, more nuanced management strategies. For
example, Hughes is testing new fencing materials to exclude frogs from fields
and hopes to create a public portal for consumers to report incidents.
“If we could better track these incidents, it might be possible to detect
geographic clusters where frogs or other small animals are more common, or times
of year they’re more active. In those areas or times, it might be as simple as
changing the crop rotation schedule or the produce variety to one where the
animals can’t hide as easily,” Hughes says.
Automation and speed also factor in when critters come home from the
supermarket.
“From a wildlife perspective, it’s really hard to screen for animals in the
context of industrial-scale harvest speed and volume. You’d have to spend
minutes checking each plant. Romaine, for example, is lettuce folded on lettuce,
where it’s easy for moisture-seeking frogs to hide. From a business perspective,
can you really spend minutes to check each leaf?”
It will take some time for the fresh produce industry to adopt co-management
methods that support food safety and conservation, but with two major E. coli
outbreaks in 2018, producers are more likely to prioritize food safety for the
foreseeable future. In the meantime, Hughes has this advice for consumers:
“Keep eating fresh produce, especially leafy greens, and if you happen to get a
live frog, please don’t release it in your backyard. Keep it as a pet or offer
it to a local school for use as an educational tool. Releasing wild animals is
how invasive species start, and could introduce disease into local frog
populations. Just don’t do it.”
The article, “There's a frog in my salad! A review of online media coverage for
wild vertebrates found in prepackaged produce in the United States,” is
published in Science of the Total Environment [DOI: 10.1016/j.scitotenv.
2019.03.254]. Authors include Daniel Hughes, Michelle Green, Johnathan Warner,
and Paul Davidson. All but Warner are or have been affiliated with the College
of Agricultural, Consumer and Environmental Sciences at the University of
Illinois. The research was supported by the USDA’s Agricultural Marketing
Service and the Center for Produce Safety.
[Source: Daniel Hughes, News writer:
Lauren Quinn, Photo by Lauren Quinn]
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