Environmental Working Group
Each week, federal investigators track 17 to 36 outbreaks of food poisoning, which can lead to severe illness and even death. Industrial livestock farming, also called factory farming, is the main cause.
According to the Centers for Disease Control and Prevention (CDC), in 2019, the most recent year for which complete data is available, there were nearly 10 million cases of food poisoning in the United States due to E. coli, salmonella and other bacteria, including nearly 1,000 deaths.
Harmful bacteria can contaminate raw produce, such as melons, lettuce, and onions, or highly processed foods, such as meat, poultry, and ice cream.
One reason, according to the Food and Drug Administration (FDA), is the way large factory farms operate, including managing the waste they generate.
Livestock waste can harbor many different types of bacteria, including E. coli, which is particularly dangerous to humans. When bacteria from animal waste contaminate nearby fruit and vegetable crops, people who eat them can become seriously ill.
Bacteria in wildlife waste and human waste sludge can also contaminate food.
Strengthened FDA policies will help reduce the number of foodborne illness cases and better protect the health of all of us.
Animal waste is more than a nuisance
Factory farms are large, concentrated facilities and feedlots that produce livestock for meat, eggs, and dairy products.
In the United States, more than 90% of farm animals are raised in these facilities. If you’ve ever eaten meat in this country, you’ve almost certainly eaten it from a factory farm. Hundreds, sometimes thousands, of cattle, pigs, chickens, turkeys and other animals are raised in large buildings or open cattle farms.
Many animals produce a lot of manure. EWG found that in 2020, animals at Iowa’s largest livestock facility produced nearly 70 times the amount of waste produced by Iowa’s entire population of 3 million during the same period.
The waste is more than an inconvenience. These contain hormones, heavy metals and bacteria, including fecal coliform, E. coli, salmonella and listeria. It may also include pathogens such as Giardia and medications such as antibiotics.
How factory farms cause food poisoning
There are two main ways that bacteria from factory farms live on the fruits and vegetables we eat.
First, manure can contaminate irrigation channels that run through feedlots, either by being washed directly into the water or by blowing contaminated dust particles from the feedlot through the air.
Without knowing whether the water is contaminated, agricultural farmers use the water from canals to irrigate their crops or mix it with pesticides to spray their crops.
Second, bacteria-laden dust from feedlots can flow into nearby fields and settle directly on crops. Although this path may seem uncommon, it is especially alarming because dust particles can travel many miles through the air.
Once harvested, contaminated produce can be shipped almost anywhere in the United States and beyond.
Deadly E. coli outbreak in Arizona
A striking example of how factory farms have triggered large-scale outbreaks is the fatal 2018 E. coli contamination of romaine lettuce in Yuma County, Arizona. Five people have died and many more have fallen ill after eating lettuce grown in the area.
The FDA found that E. coli strains from lettuce from 36 fields on 23 farms were also found in an irrigation canal near a cattle feedlot. McElhaney Feedyard is a facility located close to most of Yuma County’s lettuce fields.
The problem is not limited to factory farms in Arizona.
Wherever these facilities exist, they are dangerous. This is especially true in states that grow most of the produce consumed in the United States, such as California, where farmers grow more than a third of America’s vegetables and three-quarters of its fruits.
A recent EWG analysis found that 42% of California’s large factory farms are located within a quarter of a mile of waterways typically used for irrigation. Some are just a few feet away. One cattle station was located just 35 feet from the canal.
What the FDA can do to make food safer
Protecting yourself is harder than you think. Bacteria can contaminate both organic and conventionally grown produce. For example, studies have shown that washing lettuce does not significantly reduce E. coli, so even careful consumers can still become ill.
That’s why it’s so important for the FDA to protect people from bacteria in their food.
A practical first step is to require irrigation water testing to capture harmful bacteria and prevent them from entering crops.
After a series of E. coli outbreaks linked to leafy greens in the early 2000s, the FDA was required to set water safety standards for farms. The rule, finalized in 2024, requires farmers to assess risks to irrigation water but does not mandate water quality testing. This gap in oversight allows farmers to mitigate risk on their own.
Other federal agencies, such as the Environmental Protection Agency, could also monitor farm manure management more rigorously.
Food poisoning is unavoidable. FDA and EPA have the tools to solve public health problems, prevent millions of diseases, and save lives.
