Abstract
Every day, millions of people around the world get sick from food contaminated with harmful microbes. Some illnesses are fairly mild, causing stomach pain, nausea, or diarrhea that lasts a few days, but others can be severe or even deadly. Keeping food safe is therefore essential, but food safety is complicated. Microbes can enter food at many points, and actions taken to reduce risk can sometimes lead to food waste, higher costs, or environmental harm. Rather than aiming for “perfectly safe” food, food safety experts often work to make food “sufficiently safe” (such as a one in a million or less chance of illness) by focusing on the steps that prevent the most illnesses. New tools, including computer models and artificial intelligence, can help experts weigh these trade-offs and make better decisions. In this article, we explain how foodborne illnesses happen, how food safety decisions are made, and how new technologies are shaping smarter approaches to keeping food safe.
When What We Eat Makes Us Sick
In 2000, people across several U.S. states began getting sick with severe symptoms, including serious infections in the brain and bloodstream. Investigators traced the illnesses to a dangerous bacterium called Listeria monocytogenes, with deli meats as a likely source. Factories stopped production, grocery stores pulled products from shelves, and potentially contaminated foods were destroyed. By the time the outbreak was contained, 54 people had been sickened, 8 had died, and 3 pregnant women lost their unborn babies.
Foodborne illnesses are a common problem worldwide. The World Health Organization estimates that about 600 million people— nearly 1 in 12 people on Earth—get sick from contaminated food each year. You may have even had a foodborne illness yourself. Most cases are relatively mild, although they can feel awful: stomach cramps, nausea, vomiting, or diarrhea starting as soon as a few hours after eating and usually lasting a day or two.
Some foodborne illnesses, however, can be much more serious. Listeria monocytogenes can cause a severe infection that spreads beyond the gut to the blood or brain. In pregnant women, it can cause the loss of a developing baby, as you read in the earlier example. Certain strains of the bacterium called Escherichia coli can produce powerful toxins that lead to kidney failure. Viruses such as norovirus—the most common cause of foodborne illness in the US—can spread quickly in crowded places like schools or cruise ships, making many people sick at once. Other foodborne pathogens you may have heard of include Salmonella, Campylobacter, and Shigella, all of which can cause diarrhea and other digestive symptoms [1, 2].
Each year, around 420,000 people die from foodborne illnesses, including 125,000 children under the age of five. Young children are more vulnerable because their immune systems are still developing. Older adults, pregnant people, and individuals with weakened immune systems are also at higher risk of serious illness. Food safety is the science and practice of keeping our food supply as free from harmful microbes as possible. We depend on food safety systems every day, with every meal.
How do Pathogens Get Into Our Food?
Foodborne pathogens can sneak into food at any stage: when it is being grown, processed, shipped, or prepared (Figure 1).
- Figure 1 - Food can become contaminated with foodborne pathogens at any stage between its production and when it is eaten.
- For example, apples can become contaminated in orchards (e.g., from bird droppings), during harvesting, in packing houses and processing plants (e.g., from contaminated equipment), in supermarkets, and even in home kitchens (e.g., contamination from other foods and/or unwashed hands).
Sometimes contamination begins right where food is grown. When animals, water, and crops share the same environment, the health of one can easily affect the others. Animal waste from wild animals or farm livestock can end up in the water used to irrigate crops, contaminating fruits and vegetables with bacteria such as E. coli or Salmonella. If equipment is not cleaned properly in factories that handle meat, seafood, or ready-to-eat foods, Listeria or other bacteria can survive and spread. Because Listeria can grow even in cold, damp places, it is especially hard to eliminate from refrigerated environments like dairy or ice cream plants.
Transportation and storage add more chances for trouble. If foods that need to be refrigerated are not consistently kept cold or not cooled quickly enough, some microbes can grow and the risk of foodborne illness increases. This is similar for hot foods that are not kept hot enough, which can easily happen at buffets, for example. For several foods (such as many leftovers), time spent in the so-called temperature danger zone (typically defined as 4° C-60° C) can increase the risk of foodborne illness.
Finally, in markets or restaurants, contaminated surfaces, utensils, or unwashed hands can move microbes from one food to another. Even in your own kitchen, poor hygiene can give pathogens one last opportunity to spread. Using the same cutting board for raw chicken and salad, or forgetting to wash your hands after handling uncooked meat can transfer disease-causing bacteria.
Food safety involves keeping each step of this chain clean and controlled. But even the best efforts cannot remove all risk—there is no such thing as “perfectly safe” food.
Food Safety “Detectives”
One key role of food safety experts is to act like detectives: identifying foodborne illness outbreaks early, investigating them, and trying to stop them before too many people get sick (Figure 2). They also try to find out why an outbreak occurred and use that information to prevent similar issues from happening again.
- Figure 2 - (A) Outbreak detection involves identifying an increase in the number of new cases of foodborne illnesses caused by a certain pathogen.
- These cases may be clustered in specific areas or spread out. (B) Outbreak investigation includes interviewing patients about the foods they have eaten recently, to identify which food caused the outbreak. Experts may also use traceback to investigate the “path” taken by the food believed to cause the outbreak. Samples are tested to identify whether the food, or the environments it traveled through, contain the same pathogen that caused the illnesses in the outbreak.
This “detective” work is challenging for several reasons. First, while outbreaks that involve multiple people getting sick from a given food (e.g., hamburgers sold at a certain fast-food chain) often capture headlines, most foodborne illness cases are sporadic, meaning only one or a few people get infected by a given food. It is generally difficult to identify the sources of these sporadic cases. Another challenge is that foodborne pathogens are typically only present in low levels—for example, only one or two out of thousands of packages of a certain food may be contaminated. This means that testing foods is often not the best way to reduce foodborne illness risks.
How Scientists Limit Food Risk
Food safety experts use two main methods to control foodborne illnesses: risk-focused approaches and hazard-focused approaches (Figure 3) [3]. In some cases, such as when dealing with particularly dangerous pathogens like Listeria, a hazard-focused approach may be used. Hazard-focused approaches are food safety strategies that treat any detection of a dangerous microbe as a serious threat. This could include destruction of entire batches of affected food, even if only very low levels of pathogens—levels that are unlikely to cause illness—are found in a food or the place where a food is produced. A hazard-focused approach may provide maximum protection but can also lead to unnecessary food waste or to shutting down areas of a food-production plant that may not pose much risk to the final food product.
- Figure 3 - (A) Swabs are used to collect samples in a processing plant.
- (B) If pathogens are detected, various actions may be taken. In a hazard-focused approach, the same steps may be taken regardless of where the pathogen is detected (e.g., floor or equipment). This approach is highly protective, but food may end up wasted and effort might be spent on actions that do not really reduce risk much. A risk-focused approach may apply stricter measures (e.g., shutting down the line) if a pathogen is detected on a high-risk surface, while a less strict action (e.g., cleaning the floor) is taken if a pathogen is found in a low-risk area.
More often, experts use a risk-focused approach, which considers how likely a certain food is to actually cause illness and how serious that illness could be. Some foods are naturally riskier than others: in their raw forms, meat, eggs, and milk are more likely to carry dangerous bacteria than are foods that have been heat treated (such as canned goods) or those that are very acidic (such as yogurt). A few bacteria on a raw chicken that will be cooked pose less danger than the same bacteria on ready-to-eat deli meat, for example.
A risk-focused approach helps identify which problems are most urgent and which safety measures prevent the most illnesses. Using this information, governments can set standards for how foods should be handled, processed, and stored. Similarly, food processors can develop safety plans based on scientific evidence. For example, governments can use scientific risk assessments to determine whether to require that eggs be stored in refrigerators.
Can Food be Too Safe?
As we mentioned, no food safety system can make food completely risk free. Every food carries a tiny chance of causing illness. The goal is to make food safe enough: generally safe to eat, but not so heavily restricted that it becomes wasteful, too expensive, or unavailable. This is similar to designing cars: it would not be a good idea to require all cars to have every possible safety feature. This could make cars too expensive and cause people to use cheaper but more dangerous types of transportation (such as older, used cars or motorcycles).
Every safety step has a cost, so adding additional steps might make food safer but create other kinds of risk—to people, to resources, or to the planet. For instance, keeping food extra cold (or even frozen) during transport might keep bacteria from growing, but it uses more energy and increases greenhouse gas emissions. Requiring factories to clean equipment more often might reduce contamination but can use huge amounts of water and expose workers to harsh chemicals. Destroying an entire truckload of products after one package tests positive for bacteria might be a waste of resources if not every package is dangerous, particularly in places where food is already scarce.
Farmers face tough choices, too. Sometimes they try to keep wild animals like birds away from crops, because animals can spread bacteria through their droppings. To do this, they may clear more land for their animals or remove nearby plants or ponds that attract wildlife. While these actions can reduce contamination, they destroy important habitats for animals and insects.
These trade-offs are difficult. How much food waste, water use, or pollution is acceptable to prevent illness? Researchers are developing new ways to weigh benefits and costs of safety measures—looking at how each possible solution affects not only human health but also the environment, the food supply, and the cost of food.
Smarter Tools For Safer Food
Scientists are developing new ways to see the “bigger picture”—using computer models, artificial intelligence (AI), and new laboratory tests to understand how food safety solutions affect both people and the planet.
Computer Models: Testing “What If” Scenarios
Researchers can use computer models to combine data from laboratory tests, outbreak reports, and food-production records. Computer models can test “what if” scenarios to examine how food safety decisions might play out [4].
For example, a model might predict what happens if factories clean equipment more often or if storage temperatures change by just a few degrees. These virtual experiments reveal not only how much each step reduces foodborne illness, but also how it might affect costs, resources, or pollution. In this way, scientists can explore outcomes virtually before they happen in real life, and they can focus on the changes that will make the biggest difference.
Artificial Intelligence: Making Decisions Faster
Certain forms of AI can learn to spot patterns and make predictions from data [5, 6]. In food safety, AI can help scientists analyze huge amounts of information—such as test results from factories, food storage temperatures, and reports of foodborne illness—to quickly find safety strategies that provide the most benefit with the fewest downsides. During an outbreak, AI could work fast to help experts decide which products truly need to be recalled and which are safe to keep on shelves, preventing both illness and unnecessary waste.
New Laboratory Methods: Knowing Which Pathogens Matter Most
Not all strains of E. coli or Listeria behave the same way; some cause severe disease while others pose little risk. Laboratory tools let scientists “read” the DNA of bacteria, to understand which strains are especially dangerous and which can be safely ignored [7]. By focusing on the strains that matter most for public health, food producers can avoid wasting resources on strains that will probably not make anyone sick.
Together, these new food safety tools are creating a kind of precision food safety, similar to precision medicine in healthcare. Instead of treating all foods or microbes the same, scientists can match each problem with the most effective, least wasteful solution.
Safe Food in a Healthy World
Keeping food safe will always be a challenge. Every step in the journey from farm to fork offers chances for pathogens to sneak in, and every safety measure has both benefits and costs. What works in one community or country might not work in another. That is why many food safety experts now use a One Health approach—the idea that the health of people, animals, and the environment are deeply connected [8]. A food system cannot be truly safe if it harms ecosystems, worsens hunger, or makes farming unsustainable.
The good news is that science and technology are helping us find a better balance. Computer models, AI, and new lab methods can show us where problems start and how to prevent them, while also weighing effects on resources and the planet. There may never be one final answer to “how safe is safe enough”, but by combining science, careful and fair decision making, and care for the environment, we can build food systems that protect both people and nature. Each improvement—fewer illnesses, less pollution, and more sustainable food production—brings us closer to a world where everyone has access to safe, healthy food.
Glossary
Foodborne Illness: ↑ Sickness caused by eating food contaminated with harmful microbes or toxins. Symptoms can include stomach pain, vomiting, diarrhea, fever, and, in severe cases, lead to hospitalization or death.
Pathogens: ↑ Harmful microbes, such as bacteria or viruses, that can cause disease in people when they enter the body, including through contaminated food or water.
Food Safety: ↑ The science and practices used to keep food from becoming contaminated and to reduce the chance that eating food will make people sick.
Risk-focused Approaches: ↑ Food safety strategies that consider how likely a microbe is to cause illness and how serious that illness could be, helping focus actions where they reduce the most harm.
Hazard-focused Approaches: ↑ Food safety strategies that treat any detection of a dangerous microbe as a serious threat, often triggering strict actions even when the chance of illness is very low.
Artificial Intelligence: ↑ Computer systems that learn from data to spot patterns and make predictions. In food safety, AI can help detect outbreaks and guide decisions that reduce illness and food waste.
Computer Models: ↑ Computer-based tools that combine real data to simulate what might happen under different conditions, helping scientists test “what if” scenarios without real-world experiments.
Strains: ↑ Different versions of the same kind of microbe. Some strains can cause severe illness while others are much less dangerous or may not cause disease at all.
Conflict of Interest
MW serves as principal of Cayuga Food Safety Consulting. This company was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.
The remaining author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Acknowledgments
We wish to thank Dr. Susan Debad for providing us with a first draft and her continued collaborative input as co-author. We would also like to thank the coauthors of the original manuscript: Andrea I. Moreno-Switt, Kitiya Vongkamjan, and Sophia Johler. This work was partially supported by the United States Department of Agriculture, National Institute of Food and Agriculture, Specialty Crop Research Initiative (project award no. 2019-03139), the Artificial Intelligence Institute for Next Generation Food Systems (AIFS) (USDA-NIFA no. 2020-67021-32855), and Cornell Institute for Digital Agriculture (CIDA) (no. NYC-143301). The funders were not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.
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Original Source Article
↑Wiedmann, M., Sunil, S., Moreno-Switt, A. I., Vongkamjan, K., and Johler, S. 2026. Balancing food safety and sustainability: trade-off risk assessments and predictive modeling. Front. Sci. 4:1720772. doi: 10.3389/fsci.2026.1720772
References
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