In October 2019, the Food Safety and Operating Committee of the Innovation Center for U.S. Dairy published its updated environmental Pathogen Control Guidance Document, a comprehensive document intended to help the U.S. dairy industry control pathogens in wet and dry dairy processing environments (available at usdairy.com/foodsafety). In its guidance document, the Innovation Center details five principles that should be followed to ensure effective pathogen control. These include:

1. Separate raw from ready-to-eat (RTE);
2. Follow Good Manufacturing Practices (GMPs);
3. Institute sanitary facility and equipment design;
4. Implement effective cleaning and sani­tation procedures and controls; and
5. Initiate environmental pathogen monitoring.

These principles are in keeping with a 2022 systematic literature review showing that 10 of the 12 (83%) foodborne illness outbreaks involving pasteurized dairy products from 2007 to 2021 were due to contamination with Listeria, an environmental contaminant (Can J Pub Health. 2022;113:569-578). A similar study that looked at reported outbreaks from 1998 to 2011 coming from both pasteurized and unpasteurized cheese showed that, in 44 outbreaks stemming from cheese made with pasteurized milk, 24% were attributed to Listeria and the remainder were a mix of Salmonella, Campylobacter, Bacillus, E. coli, and others, all considered environmental contaminants (Foodborne Pathog Dis. 2014;11:545-551). The importance of focusing on the five principles of pathogen control is very clear.

One Step Further

But within the realm of environmental monitoring, is the vitally important task of environmental sampling to control pathogens enough? Will a good pathogen environmental monitoring program (PEMP) sufficiently and consistently ensure product safety and a high level of product quality? According to Neil Bogart, a highly regarded expert in dairy safety and the president of Bogart Food Safety and Sanitation Associates, Inc., an Alabaster, Ala.-based food safety and sanitation advisory firm with a primary focus on dairy processing, the answer is, “Perhaps not.”

“While swabbing, [adenosine triphosphate] ATP surface monitoring, and other environmental sampling methods are crucial steps for controlling widespread pathogens,” says Bogart, “they do not provide the complete picture in wet milk processing. Thermoduric organisms, for instance, can carry over from the raw milk supply, or pockets of contamination can become established in processing equipment where swabbing is impractical. This underscores the necessity of a robust process monitoring program to fully validate sanitation procedures and pinpoint contamination hotspots that can significantly impact quality and safety.”

When considering a process monitoring program for cheese and dairy powder processing, for example, emphasis must be placed on spore-forming bacteria due to their ability to survive extreme processing conditions, their potential pathogenicity, and because they possess strong spoilage capacities, which could lead to proteolysis, lipolysis, gas formation, and other quality defects. These bacteria can originate from the soil, feces, bedding, feed, or milking equipment but can also enter the milk via contaminated teats, milking cups, bulk tanks, or transport tankers. Pockets of contamination can also develop within the processing plant due to failures in milk handling, sanitation, or preventive maintenance. Extended production run times exacerbate the problem. Endospores formed by these organisms may survive pasteurization and subsequently germinate into vegetative cells that may be psychrotolerant but prefer to grow in warm conditions, giving them an even greater chance to contaminate many dairy processing environments (Front Micro. 2017;8:1-15).

Sporeformers of primary concern to dairy processors are members of the genera Bacillus and Clostridium; however, except in certain cheese processing, concern over the anaerobic Clostridium is often less than that for their aerobic counterparts. While many sporeformers are not pathogenic and are seen primarily as indicators of hygiene during milk collection, transport, or processing, certain members of these genera are well-known pathogens and, therefore, worrying from a food safety standpoint.

The formation of homogeneous or heterogeneous bacterial biofilm communities on the internal surface of processing equipment is of particular concern to dairy processors because, when present, biofilms can lead to persistent problems of microbial contamination that are often intermittent and hard to pin down. Heat exchangers, pipelines, tanks, gaskets, seals, and other stainless steel processing equipment are primary sites for biofilm formation, especially once a conditioning layer of milk protein is laid down on the surface of the equipment during processing (Comp Rev Food Sci Food Safety. 2012;11:133-147). Biofilm formation is also a leading cause of fouling of reverse osmosis and microfiltration membranes and is a frequent concern in the continuous step of evaporation before spray drying, making these processes especially critical in controlling contaminant outgrowth (Food Res Int. 2021;150:110754; Comp Rev Food Sci Food Saf. 2014; 13:18-33).

Real World Example

The importance of process monitoring was exemplified in a 2007 research study published in the International Journal of Dairy Technology (2007; 60:109-117.). In this study, a team of New Zealand researchers monitored a process stream during five whole milk powder manufacturing runs, each approximately 18 hours in length. The plant was operating at the rate of 40,000 liters per hour. A clean-in-place (CIP) cleaning occurred after every run, and after every five runs the evaporator and direct steam injection unit were manually cleaned to remove foulant build-up. Samples were collected every two hours during processing from 16 sampling locations, beginning with raw milk ahead of pasteurization, after pasteurization, following each of five evaporator passes, and through to the finished product. In addition to vegetative cells, samples were tested for the presence of endospores.

The study found low or no spore counts in samples taken from the end of raw milk treatment, although vegetative cells were found in low numbers. The researchers concluded that in this study, raw milk treatment had very little influence on the thermophile numbers of milk destined for powder manufacture.

Conversely, beginning with samples taken from between the plate heat exchanger and evaporator and carrying on through two stages of evaporation, there was a consistent increase in both vegetative cell growth and spore formation. Spores and vegetative cells were initially detected after about nine hours of production, and by 18 hours, counts exceeded 10,000 colony-forming units per milliliter (cfu/mL). Vegetative growth and sporulation did not increase during evaporator stages three through five. In some production runs, vegetative cell and spore levels decreased during processing after the second evaporation stage, but in other runs, the contamination levels remained relatively consistent.

The authors concluded that the study “confirms that spores were forming within the milk powder manufacturing process and were not a result of external contamination.” They further noted that low levels of contamination could come in from the raw milk, but the contamination found in later stages of production predominately arose from sporulation occurring within the plant, notably from bacteria trapped in foulant (from the evaporator or separator, for example) that remains in the equipment between CIP runs and may be only partially removed during manual cleaning. In this case, the heat exchanger, the preheat section of the evaporator, and the evaporator itself appeared to be the predominant sites of biofilm formation.

Every Situation is Different, but Some Things Remain the Same

Maintaining microbiological quality and safety in dairy processing presents a considerable challenge to dairy processors. In dairy operations where controlling thermoduric, thermophilic, and post-pasteurization contamination is requisite for ensuring consistent quality and safety, wet process monitoring is an essential adjunct to environmental surface monitoring. Microbiological sampling of wet process critical control points helps quality assurance professionals control contamination, validate cleaning and sanitation procedures, and identify sources of milk contamination coming from the raw milk supply, processing equipment, or the surrounding environment.

Every dairy processing operation is different, and processes determined to be “critical” will vary from process to process or plant to plant. However, some processes or plant operations require careful monitoring in every milk processing environment. These include the raw milk both at the time of receipt in the plant receiving bay and immediately before pasteurization; plate heat exchangers; microfiltration or reverse osmosis filtration equipment; any open vats or vessels, including cheese vats and blending or mixing vats; evaporators; scraped surface heat exchangers; filling equipment in wet milk filling operations; and other specialty equipment that may run for extended periods between cleaning cycles. In each case, biofilm formation is a threat, and it is critical to sample both upstream and downstream of the equipment to afford the ability to determine if biofilms are developing on internal surfaces.

Thermoduric and thermophilic vegetative organisms and their endospores are found frequently in dairy products, including milk powders. Single-species and multi-species biofilms formed on milk contact equipment surfaces are a primary contributor to pathogenic and spoilage organism bioburden. These biofilms are difficult to remove from milk processing environments and, if allowed to mature, can cause immeasurable damage to product safety, quality, and reputation, leading to disastrous economic consequences.

As Neil Bogart concludes, “From a practical viewpoint, a carefully conceived and well-implemented process monitoring program that allows managers to optimize and validate sanitation procedures and safely regulate plant operations is about the cheapest insurance money can buy.”

Johnson is a biotech innovator with a 25-year tenure founding and developing companies to advance health technology. A trailblazer in HACCP application in the dairy industry, his early career focused on enhancing dairy safety and quality assurance. He holds advanced degrees in microbiology and biochemistry and serves on the board of directors of QualiTru Sampling Systems.

Food safety has always been crucial, but with the rise of pathogens and challenges from pests and chemicals, it’s vital for food and beverage manufacturers to have strong food safety leaders. This has led to a strong emphasis on developing the food safety leaders of the future.

Jill Stuber, founder of Catalyst, a coaching and leadership development company for the food industry, and vice chair of the Developing Food Safety Professionals Group of the International Association of Food Protection (IAFP), says that possessing solid technical skills is essential in the food safety space. “We’ve seen people improve their work outcomes and get promoted when they practice and adopt soft skills such as self awareness, creating safe spaces, and leading with curiosity,” she says. “Leaders who empower team members and invest in personal and professional growth are more likely to enhance their career growth prospects, as they will be known for growing competent, dynamic, and innovative teams.”

Takashi Nakamura, PhD, vice president of food safety for Fresh Del Monte, highlights three areas of focus in building any career: attitude, aptitude, and attendance. All are necessary to become a strong food safety leader. “Resiliency is key when it comes to food safety, since the next outbreak or recall is just around the corner,” he adds. “Our days really begin on Friday since testing begins on Monday, so the ability to manage oneself both mentally and physically in a 24–7 environment is that we can never control. This world is that of pathogens, and it’s important to know that we inhabit their world, and not the other way around. There will be more tough days than easy days in our business and function.”

Aptitude should be a top characteristic in a food safety leader, and candidates should build themselves up as subject matter experts. “Establishing credibility and empowering others in this type of job function requires constant vigilance in developing your skill sets and competencies,” Dr. Nakamura says. “Don’t settle for what you have achieved, but rather look for the opportunity to build via a disciplined and rigorous program—regardless of the degrees you have or the training you’ve achieved. The world is constantly evolving and adapting, and as stewards of critical functions in an organization, we as professionals need to do the same.”

He also notes the importance of regular on-site visits that include visiting the floor, walking the fields, and touring the facilities. “This function is not one where you stay behind a desk in an office,” Dr. Nakamura says. “You will need to see, touch, and hear what is going on in your operations. Be present to those other functions and engage. Be engaged in associations, stay in touch with universities and institutes, and establish and expand your network.”

Food safety is a rapidly evolving field, so professionals must stay ahead of emerging trends and technologies to enhance their career growth. Continuous education and training are critical. “Professionals can stay ahead of emerging trends by regularly reading industry publications, research studies, and reports related to food safety issues and events,” says Jorge Hernandez, vice president of quality assurance for the Wendy’s Company, who has over three decades of experience as a food safety leader. “They can also pursue additional training, certifications, attend workshops, webinars, conferences, and/or taking online courses related to food safety. This will help them enhance their knowledge and skills in the field.”

Key Skills

Jennifer McEntire, PhD, founder of Food Safety Strategy and former chief food safety and regulatory officer at the International Fresh Produce Association, shares that future food leaders should possess strong foundational knowledge of food safety hazards and critical thinking skills to determine when these hazards become risks. “Knowing how to do the research to gather this information to make data-driven decisions is critical,” she says. “It’s not just analytical skills though; it’s important to listen and learn from others. Leaders also have a natural curiosity.”

Hernandez says that essential skills for aspiring food safety leaders start with building credibility. “This is a non-negotiable for aspiring leaders,” he adds. “Your credibility is the bedrock of leadership and essential to your success in any organization. You must have a deep knowledge and understanding of food safety science that drives the food safety standards and regulations. It is the foundation on which trust is built, and it is what allows any aspiring food safety leader to influence others to engage on the pursuit of common goals.”

Effective communication is another key skill that helps people advance in the field. “From gaining management support for budgets, programs, or changes to the status quo, to being able to educate and train staff on the importance of food safety, food safety protocols and communicating with regulatory agencies, an aspiring food safety leader must seek to be an effective communicator who can clearly and concisely communicate the food safety vision, ideas, changes, and the benefits those bring,” Hernandez says.

Dr. Nakamura advises workers to be results oriented early in their careers and continuously develop their skills, and think of themselves as a brand and taking stock to determine how to succeed. “Get solid external certified basic trainings in HACCP, GMP, traceability (FSMA 204), produce safety rule (and its requirements such as PCQI) if going into the produce field,” he says. “Sanitation should be one of your key areas of focus, as we don’t have enough great sanitation trained individuals. Commercial food sanitation has very well respected and world renown training certification courses. Going back to being a subject matter expert, develop yourself to be a specialist in an area such as sanitation, microbiology, etc.”

Critical thinking is another important trait of an aspiring leader: Be able to seek the proper information, to analyze data to identify potential food safety risks, and to develop preventive solutions to ensure the safety of the food supply chain. “They must also have courage,” Hernandez adds. “This can be one of the hardest things for any leader, yet it is essential for any aspiring food safety leader. As an old friend once told me, ‘If you want everyone to like you, do not go into food safety; go sell ice cream.’ Having the courage to speak up, make difficult decisions, taking responsibility for results, apologizing for mistakes, or giving bad news is not easy, but it’s a defining characteristic of true food safety leaders.”

Dr. Nakamura recommends initiating and driving research programs with universities and institutes for your organization. “External engagement with key educational and research universities will foster you and your team’s ecosystem and network,” he says. “This activity will drive two areas—it will keep you in touch and abreast of new technologies and how the next generation are looking at current and future state problems and issues; and it will allow you to develop a network of like-minded professionals that can assist you in finding a solution to your organization’s problems, potentially being an active resource and toolbox for future talent needs.”

Ambitious food safety leaders must also embrace continuous learning and improvement. As foodborne pathogens evolve and the environment changes, science provides new insights. It is imperative for future food safety leaders to stay current on the latest trends, technologies, tools, and best practices to continuously improve their knowledge and skills.

The Power of Networking

A key strategy for career advancement is networking. Building a strong network of industry professionals and participating in professional organizations will help you stay informed of emerging trends and opportunities.

Networking allows professionals to connect with industry peers, experts, and potential employers, expanding their professional contacts and career advancement opportunities. By attending industry events, conferences, and networking functions, professionals can build relationships, exchange ideas, and stay informed about emerging trends and opportunities in the food safety sector. “Networking can also help professionals access hidden job opportunities, referrals, and recommendations from within their professional network,” Hernandez says. “By building strong relationships with industry, academia, and regulatory contacts, professionals can increase their visibility, credibility, and chances of securing job interviews and career advancement opportunities.”

Hernandez also suggests that aspiring leaders seek mentorships with seasoned professionals. “Mentors can offer career advice, feedback, and support to help professionals set goals, make informed decisions, and navigate career transitions in the food safety sector,” he says. “They can also provide valuable insights into industry trends, job opportunities, and professional development pathways.”

When deciding on the perfect job in food safety, Dr. McEntire suggests talking with many people in food safety and adjacent fields to learn about their career paths and current roles to determine what’s most interesting.

Ultimately, food safety professionals should carefully assess these factors and conduct thorough research to select a food sector that aligns with their interests, goals, and values, setting the stage for a rewarding and satisfying career in the food safety industry.

Foodborne viruses can be tough to prevent and mitigate. Some can’t be cultured, so they are difficult to analyze. Others aren’t affected even by strong disinfectants, so intervention is ineffective. In the past decade, an additional virus, hepatitis E, joined norovirus and hepatitis A as a top three concern for human food safety.

To tackle these challenging foodborne viruses that can cause serious human illnesses, the Food and Agriculture Organization of the United Nations and the World Health Organization (FAO/WHO) are holding a series of meetings focused on microbial risk. The first Joint FAO/WHO Meeting on Microbiological Risk Assessment (JEMRA) convened in September 2023 in Rome and focused on foodborne viruses of top concern for public health, analytical methods, and contamination indicators. The second meeting, which took place in February 2024 in Geneva, discussed prevention and intervention measures for these viruses. A third meeting is planned for later in 2024 and will focus on evaluating risk.

The final reports for the first two meetings are still in progress, with only summaries released so far. Experts involved in the meetings said significant advances have been made in the study of foodborne viruses; these have helped researchers understand the science of viral mitigation since the inaugural JEMRA meeting 16 years ago, a milestone event that was the first time the issue of viruses in foods was brought to international attention.

“We have improved norovirus surrogates and ways to study human norovirus, and we have better detection methods, like digital PCR,” says Kalmia Kniel, PhD, associate chair of the department of animal and food sciences at the University of Delaware in Newark. She adds that thermal treatments are often relied on to inactivate viruses, but there are promising non-thermal technologies being studied, including cold plasma, chlorine dioxide, and some chemical disinfectant combinations.

The Biggest Threats

Dr. Kniel chaired the 2023 meeting and was a member of the expert committee that reviewed recent scientific developments, data, and evidence associated with foodborne viruses. JEMRA will update and provide scientific advice to the Codex Committee on Food Hygiene, which requested the series of meetings. The Codex committee will use the information for its international recommendations and standards. The expert committee also considered trade implications of possible standards to ensure that food safety does not become a trade barrier.

In reviewing viruses associated with human foodborne illness, the expert committee identified human norovirus as the leading cause of viral foodborne illnesses, followed by hepatitis A and hepatitis E. The ranking considered the frequency of illness, the clinical severity of the disease, and the food most often linked to the virus; however, while hepatitis A and hepatitis E were ranked equally behind norovirus in terms of frequency, they were higher than norovirus in terms of clinical severity. The committee lacked sufficient data to rank other viruses, including rotavirus and sapovirus.

In terms of the foods most associated with the viruses as a potential public health threat, prepared food, frozen berries, and shellfish—in that order—are associated with norovirus. For hepatitis A, linked foods are shellfish, frozen berries, and prepared foods. Those two viruses are transmitted via contamination by feces exposure. For hepatitis E, a zoonotic virus, pork and wild game are associated, and the virus is transmitted from animal to human.

The committee considered only water used in food production, in processing, in preparation, or as an ingredient, not water intended only for drinking, in its assessments.

Viral foodborne disease has a substantial impact on morbidity and mortality globally, but surveillance data is sparse, and there is the potential for asymptomatic shedding, so it is difficult to craft prevention and control strategies.

Norovirus causes about 125 million cases of foodborne illness and 35,000 deaths worldwide annually, according to the committee’s summary, including severe outcomes such as hospitalization and death, especially in children younger than five years old, the elderly, and immunosuppressed people, who may shed the virus for extended periods. Hepatitis A causes about 14 million cases of foodborne illness and 28,000 deaths each year globally, but there are significant regional differences attributable to endemic prevalence, vaccine use, and international food trade. There are no global estimates for hepatitis E, which can damage the liver, the meeting summary said.

“The JEMRA committees discuss foodborne viruses in a global context,” Dr. Kniel said. “We need to keep in mind that our food system is global in nature, which means we need better surveillance of viruses in all countries in order to help each other.”

Dr. Kniel said that since the 2008 JEMRA report, international and national standard methods have been developed and validated to detect and quantify human norovirus and hepatitis A virus in foods. Methods released since that report include the International Standards Organization’s ISO-15216-1:2017 and ISO-15216-2-2019. These are used widely to detect norovirus and hepatitis A in leafy greens, soft fruits, and shellfish, and as a benchmark to validate new methods, the committee’s summary said. There is no ISO method for prepared foods. Methods to detect hepatitis E in meats are under development.

The committee said infectivity assays are needed for wild-type viruses, as there still is no definitive way to tell infectious from noninfectious viruses using molecular amplification.

It recommended that countries consider building capacity to help with adopting and training in methods for detecting viruses in foods and the environment. “Appropriate global actions will help alleviate the anticipated increase in public health risk from viral foodborne illness arising from population growth, the climate crisis, and globalization of food supply chains,” the summary from the 2023 meeting said.

Prevention and Mitigation

Prevention is the preferred focus now, given the difficulty and expense of mitigating infected foods, says Lee-Ann Jaykus, PhD, rapporteur of the March 2024 meeting and a member of its expert committee. She says the viruses are not culturable organisms and cannot be grown in a lab like bacteria can, nor can they be culturally enriched. There is no host cell in a culture with which to propagate them. It’s necessary to concentrate and purify them from a sample and use reverse transcription polymerase chain reaction to detect the viruses. “We have standardized methods to detect these viruses in selected commodities, but they have some inherent disadvantages because of the limitations of not having a culture,” Dr. Jaykus says.

Limitations include the fact that even when a viral nucleic acid is detected, it doesn’t necessarily mean there is an infectious virus, she said. Real-time polymer chain reaction (RT-PCR) is a complicated method, and it is easy to lose viruses in the first steps, so it is not as sensitive as needed. “These are limitations not because the science is bad,” she says. “The science is the best it can be as it currently stands. There are limitations because we can’t grow these things.”

One focus of the second meeting was contamination routes for the virus to humans. Fecal matter and vomit from infected humans are the primary sources of contamination for norovirus and hepatitis A to get to humans through affected waters, food handlers carrying the viruses, and surfaces, because the viruses can live for weeks on surfaces, Dr. Jaykus says. The zoonotic hepatitis E virus is present in the meat, organs, tissues, and excretions of infected swine and game animals and gets transmitted through exposure.

Because the viruses persist in the environment for long periods and are resistant to many treatments, prevention is the key strategy to control foodborne viruses, Dr. Jaykus says. One example of prevention is reducing the viral load in shellfish by treating wastewater, but that requires infrastructure investment. Another is using production-related strategies to reduce contamination of fresh and frozen produce. Virus inactivation methods also are under investigation.

The committee recommended some directions for future research and development, including early identification of contamination hotspots using wastewater surveillance, for example, and technologies such as satellite imagery and hydrographic dye studies to predict virus dispersion. It also recommended using emerging scientific data to develop surface disinfectants and hand sanitizer formulations with greater efficacy against environmentally stable viruses. After all, hand sanitizers were effective in reducing transmission during the COVID-19 pandemic.

“Following up on the COVID-19 pandemic, it is critical that we launch surveillance studying the health of animals, humans, and the environment to identify important zoonotic viruses before the next pandemic,” says Dr. Kniel, who, like Dr. Jaykus, was surprised to see the hepatitis E virus added to the list of top foodborne virus concerns since the inaugural JEMRA meeting 16 years ago. “It is frustrating to continually talk about the need for better surveillance to better understand foodborne virus transmission and the attribution of disease to a specific virus.”

Table 1: Foodborne viruses and foods of highest public health concern

Source: FAO/WHO.

In February 2024, a group of Canadian and American researchers published a study in the journal Environmental Pollution that analyzed the presence of microplastics in 16 protein-based foods commonly found in supermarkets (Environ Pollut. 2024;343:123233). The products included plant and animal proteins from both marine and terrestrial animals and with different levels of processing, such as breaded shrimp, Pollock fillets, chicken nuggets, pork loin chops, plant-based nuggets, and tofu.

The analysis found microplastics contamination in all sampled foods, with no significant difference between animal and plant-based proteins. Another takeaway was that more processed products, such as chicken nuggets and tofu, contained more microplastics particles than those with minimal processing, such as Pollock fillet or pork chops.

The correlation between levels of processing and microplastics contamination is not surprising. As Madeleine Milne, PhD, a researcher at the University of Manitoba and co-author of the study says, “as food goes through additional processing steps, there might be more opportunities for contamination from microfibers of synthetic polymers used for workers’ clothing or rubber pieces from conveyor belts.”

This study is not the first one indicating microplastics contamination generated in food processing environments. In 2001, in Japan, a research study found that the levels of phthalates in retail packed lunch meals substantially decreased after PVC (polyvinyl chloride) gloves containing DEHP (a common phthalate plasticizer) were banned during production and cooking processes (Food Addit Contam. 2001;18:569-579). In 2020, researchers from the Instituto Politécnico Nacional in Mexico analyzed milk samples and found microparticles of sulfone polymers, which are commonly used for membrane materials in dairy processes (Sci Total Environ. 2020;714:136823).

Microplastics contamination in food products creates a potential new food safety risk for manufacturers, especially when one of the pathways is the very processing environment they are responsible for; exactly how to manage that risk is something researchers are still trying to determine.

Worrying Signs

One of the main questions about microplastics is their actual toxicity. “Humans have been exposed to different types of particles for thousands of years; they ingest them and digest them without anything bad happening. We don’t know yet whether microplastics are any different,” says Mohamed A. Abdallah, PhD, associate professor in persistent organic pollutants and emerging contaminants at the University of Birmingham in the U.K. and a member of the Birmingham Plastics Network, an interdisciplinary team of experts aiming to address the global plastics waste problem. “We still don‘t have a full understanding of the toxic implications of human exposure to microplastics, and we haven’t been able to establish a toxic dose level (TDL), which is the lowest dosage known to have produced signs of toxicity. We have reasons to worry, though.”

One of those reasons is the small size of microplastics, which allows them to potentially reach any corner of the human body. Most microplastics are the product of the breakdown of plastics into smaller particles. Their size ranges from one micrometer (one thousandth of a millimeter) up to five millimeters. “Current findings are focusing on microplastics in the smaller size range, less than 50 micrometers, which can be carried around by blood and accumulate in organs,” says Dr. Abdallah. “Microplastics were found in tissues, bones, genitals, and there are even indications that they can cross the cerebral spinal barrier and reach the brain.”

The very presence of these extraneous particles in the human body may be reason for concern: “There have been studies on mice pointing to microplastics as a cause of myocardial toxicity,” says Susanne Brander, PhD, an associate professor in the College of Agricultural Sciences at Oregon State University in Corvallis, who focuses on endocrine disrupting compounds and microplastics in aquatic organisms. “The hypothesis is that these particles could interfere with cell function and cause muscle tissue inflammation.”

Another potential source of toxicity are the additives used to give plastic certain attributes, such as color, texture, or flexibility: “A lot of those chemicals, bisphenol A for example, have been shown to be endocrine disruptors, which means they can bind to hormone receptors on cells and disrupt the messaging that happens between them and organs,” says Dr. Brander.

The damage that these plastic additives cause to human health are well known. In 2022, a research study published in the US was able to quantify the societal costs of cardiovascular mortality associated with phthalate exposures to at least $39 billion per year (Environ Pollut. 2022;292:118021).

Growing Pains

In fact, the research on microplastics contamination in food and its toxicity in humans is relatively new. It evolved from the study of plastic pollution in marine environments and then in fish. “Up until a few years ago, most of the studies were focused on the occurrence of microplastics in oceans and in waterways. Funding sources for research focused on humans have just started to materialize. If you got a grant, and it‘s a three-year or five-year grant, you’re probably still working on it,” says Dr. Brander.

A significant issue confronting research on microplastics in food is measurement techniques. Measuring the content of microplastics typically goes through three stages: chemically digesting the sample, removing the food part, and using microscopy and spectroscopy to identify and count the particles. Currently, however, there is no standard method for measuring microplastics. “The protocol is well established, the problem is, it takes a lot of time and it‘s a very intensive and expensive process due to the labor that‘s required. One sample has been estimated to take up to 60 hours from start to finish,” says Dr. Brander.

“A lot of labs are trying to figure out how to reduce the manual labor of having to look under a microscope at samples and pick particles. But until then, it will definitely be a challenge, because each measuring method has its benefits and limitations. Some techniques can only measure larger microplastics, while others can examine smaller particles,” says Dr. Milne.

Because not all techniques are available to all researchers, the size range of microplastics they investigate might be limited by the instrumentation they have access to. These limitations make it difficult to compare results of different studies: “If a hypothetical study on fish found 50 particles of microplastics in a sample and another one found 100 particles, you couldn’t simply say the second one was more contaminated, because they may be measuring completely different size ranges,” says Dr. Abdallah.

Once these issues are resolved, however, the progress on microplastic detection will pave the way to the study of nanoplastics, whose size can be as small as a nanometer, which is the thousandth part of a micrometer. Nanoplastics are still a largely unexplored side of plastics contamination: “They’re the next frontier and one of the biggest challenges,” says Dr. Brander. “We know that they’re there, and the technology to quantify them is improving, but it’s still expensive and it‘s not available to most labs that work on microplastics.”

Reducing Microplastics in Food

Food safety regulations and standards don’t yet have any specific requirements around microplastics—this may change in the future. “Microplastics in food products is a rising concern among both food manufacturers and the public,” says Bosco Ramirez, senior director of the North American Laboratory Division of NSF International, a global certification body for food safety schemes. “Hopefully, as research progresses and methodologies improve, specific requirements for microplastics will be introduced to existing food safety standards. It’s also possible that new standards or government regulations will be developed. Collaboration among experts, industry stakeholders and regulatory agencies will be key in deriving robust methodologies to detect and quantify microplastics.”

Right now, there’s not a lot that food companies can do to tackle the issue of microplastics contamination directly: “A lot of food and non-food companies are concerned about whether they’re inadvertently generating microplastics or are using materials that contain microplastics,” says Caroline Potter, VP of sustainability at Sagentia Innovation, an R&D consultancy based in the U.K. “But if you find microplastics contamination in a food processing environment, it would be very difficult to understand how much of it came from the processing line, from water, from air pollution, or from the people working in the facility. And without knowing that, it would be very difficult to take precautionary measures.”

The best strategy for food manufacturers is to reduce the use of plastics across the board: “Part of the problem is coming from plastic packaging and the way it’s mismanaged after use, which leads to the breakdown that generates microplastics,” says Potter. “Food companies should definitely look at using alternative materials or use plastic packaging designed in a way that it can be easily recycled, so that it won‘t make its way into the environment.”

The problem, however, is more nuanced, Potter adds. “Sustainability isn’t just one thing. Plastic leakage is an important aspect, but companies are also looking at their carbon footprint, and with plastic being a very lightweight material, it can be the lower carbon footprint packaging option in some cases. When evaluating the alternatives, our advice is to try and balance all the different sustainability trade offs, whether it‘s carbon footprint, water usage, or impact on biodiversity. There’s no point in finding a solution that has a better impact in one area of sustainability, just to have a worse impact on another.

Tolu is a freelance writer based in Barcelona, Spain.

The planet is warming, and extreme weather events are becoming more frequent and severe. Across the globe, changes in climate are placing enormous pressures on entire ecosystems. Years-long droughts, severe rains and flooding, and frequent wildfires are among the increasingly disruptive weather events that are having cascading effects on perhaps the most essential ecosystem for humans—the food ecosystem.

While cyclical weather events such as El Niño and La Niña play a vital role in shifting weather patterns and events, it’s the long-term trend in climate changes wrought by human activity that most experts believe, and science supports, exacerbate these cyclical patterns to a degree by which the health of ecosystems cannot be maintained or, if unimpeded, reversed. From depleting the soil of nutrients to interfering with the proper storage of foods for human consumption, climate change holds the potential to disrupt all aspects of the food chain. Ensuring food safety in this climate is an ever-growing concern.

For food producers and processors already tasked with the continuous, difficult mandate to ensure the safety of their food products, the task may feel Sisyphean amid new and uncertain challenges all along the food chain caused by the warming planet. “Predicting the most significant impacts of climate change on food safety is challenging given the dynamic nature of climate change,” says Sara Bratager, senior food safety and traceability scientist at the Institute of Food Technologies (IFT). Rather than one dominant impact of climate change on food safety, she thinks it more likely that there will be a collection of emerging risks whose impacts will vary regionally.

For Bratager, the problem presented by climate change to food safety is one that carries opportunity. “Climate change is encouraging us to think differently and more comprehensively about food safety practices,” she says.

Brenda Zai, a PhD candidate in the department of population medicine at the University of Guelph in Ontario, Canada, put a stronger note on a similar message. “It is not necessarily the impacts of climate change on food safety risks that are the major concern; it is how solutions and resources are developed,” she said.

She’d like to see more of a focus on mitigating and adapting to climate change rather than the current focus on preventing it. “Ultimately, climate change impacts are inevitable; therefore, a shift in mindset is central to adapting to these impacts to lessen their burden,” she says. Without this shift, she thinks “the agri-food industry and public health will continue to be vulnerable to climate-sensitive food safety risks.”

Focusing on climate change as a catalyst for improving food safety solutions, there remain several big questions. What are the effects of climate change on food safety that can spur more comprehensive food safety practices? How can food producers and processors position themselves to best handle these effects and strengthen their food safety protocols?

Risks to Food Safety

Rising temperatures across the globe, with 2023 as the hottest year on record according to a 2024 report from the World Meteorological Organization, are exacerbating a range of food safety concerns. Water and crop contamination are major concerns, as detailed in a 2020 report by the Food and Agriculture Organization (FAO) of the United Nations, “Climate Change: Unpacking the Burden on Food Safety.” From worsening algae blooms along coastlines and lakes that harm marine plants and animals, to higher incidences of foodborne pathogens caused by heavy precipitation events and flooding, to increases in and expanded geographical areas with mycotoxin contamination in staple crops, the incremental but impactful heating up of the earth’s water and land is presenting new challenges to keeping food safe all along the food chain.

And the risks are spreading globally. “Some of the greatest food safety risks caused by climate lie in the emergence of previously not regionally known threats,” says Markus Lipp, PhD, senior food safety officer, Agrifood Systems and Food Safety Division, FAO, Rome.

Dr. Lipp points to many regions of the world, for example, that have not previously been affected by food safety risks related to mycotoxins in various crops or marine biotoxins in seafood. Unlike the many tropical countries for whom these risks are well known and who have learned to manage these risks, Dr. Lipp says these newer regions of the world have less practice and know-how on how to manage such food safety risks. “This is a particular concern as the rate of climate change is rather fast and results therefore in an immediate concern,” he says.

Bratager also underscores the particular threat of mycotoxin contamination of crops in non-tropical areas, in which warming temperatures and extreme weather events such as drought and flood are creating ideal conditions for certain mycotoxins to proliferate. She cited the rise in aflatoxin contamination in maize in South and Central Europe over the past decade, particularly in Italy, Serbia, and Hungary. “This shift highlights the expanding geographical range of food safety risks driven by climate change,” she adds.

The risks to food safety go well beyond the pre-harvest stage. Other, less direct effects of climate change include disruptions in food processing and production as well as consumption. Extreme weather events can “disrupt food safety processes and interfere with protocols related to food processing, transport, and storage,” says Elena N. Naumova, PhD, a professor in the nutrition epidemiology and data science division at the Friedman School of Nutrition Science and Policy at Tufts University in Boston. Power outages caused by extreme weather, for example, can impair refrigeration of perishable products of high nutritional value such as meat, poultry, fish, dairy, and eggs across the food supply chain, from production and distribution sites to retail stores to consumers’ homes. Microbial, physical, and chemical spoilage of foods will incur high costs for food producers and processors, including more food recalls. “The environmental and climate changes may be incremental, but the overall effects, both direct and indirect, are likely to be substantial enough to trigger foodborne outbreaks,” says Dr. Naumova.

Collaboration Needed to Mitigate Risk

Although climate-sensitive food safety risks are garnering more research attention, Zai notes that significant knowledge gaps remain. “Consequently, mitigation and adaptation strategies are under-developed and require further efforts and resources,” she says.

She cautioned against tunnel vision in addressing the impacts of climate change on food safety and instead emphasized a collaborative approach among experts across multiple disciplines (agri-food, public health, climate science, and policymaking) to provide holistic solutions akin to the Centers for Disease Control and Prevention’s One Health framework approach.

What this means in practice is taking a stronger, proactive approach to mitigating food safety risks. For food producers, this may mean increasing current efforts to introduce new methods to adapt to the increased risk of crop contamination. Zai pointed to several methods that could be employed: integration of climate-resilient crop varieties that are able to withstand extreme weather conditions, and plant pathogens that can pose a risk to consumers after harvesting, diligent water management and testing to prevent waterborne pathogens from contaminating crops, and pest management.

For governments, public health, and policymakers, it means undertaking more data and research-driven activities such as developing reliable surveillance systems that integrate climate data and environmental sampling data to project the likelihood of contamination through modeling methods, which could also be applied to developing early warning systems, according to Zai.

Essential for strong collaboration among all stakeholders is a willingness to share knowledge and best practices. For example, regions newly experiencing mycotoxin risks can learn from tropical areas with long-standing experience managing these contaminants, says Bratager. “Data sharing is equally important,” she said. “It enhances our ability to predict and prevent foodborne illness outbreaks by improving the identification of food safety risks and enabling more targeted mitigation strategies.”

For experts who use data analytical tools to track food-borne outbreaks, access to data that is more streamlined across agencies is critical but difficult. Dr. Naumova, who is an expert in developing analytical tools for spatio-temporal and longitudinal data analysis applied to disease surveillance, emphasized the severe fragmentation of data across various agencies that makes it difficult to get the needed precise data on where, when, and how food contamination and exposure to pathogens occur, spread, and manifest. “Our task is to assemble all records into an analyzable form, considering the potential delayed or cascading effects of extreme weather events and health responses,” she says. “This data preparation and sophisticated analysis is a tedious, time-consuming process requiring internal checks and controls and proper expertise.”

According to Dr. Naumova, developing a tool that can mitigate the food safety risks caused by climate change requires an investment in dollars, time, and commitment that would have an impact akin to creating a national infrastructure. “We need integrated early warning systems to mitigate the risks,” she said. These would include assessing the potential for an extreme weather event at a given time and location; assessing the extent of food safety risks, including population vulnerability; providing projections for health officials and relevant stakeholders for different stages of risk (anticipation, alert, and alarm); developing, testing, and providing tailored mitigation strategies and monitoring their implementation; and assessing the aftermath and adjusting for further preparedness and learning.

Dr. Naumova emphasizes the need to keep the focus on targeted mitigation strategies. “The effects of climate change are global, but the solutions have to be local and well-tailored to local needs and challenges,” she says.

Thinking Globally and Acting Locally in an Uncertain Climate

One key challenge when talking about food safety risks linked to climate change is the unpredictability and variability of the effects of climate change at any given time in any given place. New thinking and new tools can help transition to acting more proactively to mitigate risks to food safety under the uncertainties of climate trends.

New thinking may mean a shift to a more proactive way of thinking about food safety issues affected by the changing climate. The FAO advocates integrating what it calls a structured foresight system to get people thinking about what climate-related scenarios could occur in the medium-to-long term that could impact food safety. In its 2022 report, “Thinking About the Future of Food Safety: A Foresight Report,” the FAO describes foresight as a structured futures-thinking approach involving multidisciplinary collaboration aimed at understanding trends and uncertainties and guiding decision-making processes towards achieving desired goals. Such proactive thinking goes beyond the traditional early warning food safety systems that are aimed at rapid response to outbreaks or seasonal or annual climate conditions predictive of food safety risks.

“When we are prepared, when we have the foresight to understand how the world and its climate will change and what the consequences for food safety are, we can avoid disruption,” says Dr. Lipp. Acknowledging that this mindset will not work for everything, he thinks it will work for a great many things and allow for a planned approach to deal with unforeseen events. “Without foresight, too many issues turn into an emergency that will overwhelm our systems,” he adds.

New tools, especially at the local level, can help foresee and anticipate regional and local climate trends. A new tool recently launched by the University of Minnesota Climate Adaptation Partnership (MCAP) is one such tool. Called MN CliMAT, the interactive online tool offers highly localized climate projections for Minnesota by providing detailed information on future climate variabilities.

Katie Black, an extension educator focusing on climate resilience and adaptation at MCAP, says the tool fills a needed gap in providing highly localized climate information. “Many reports discuss the expected changes to our climate across the globe, but to make decisions at the regional, city, or farm scale, we need information at that same scale,” she adds. “MN CliMAT’s data are more relevant and useful for the many climate change adaptation efforts happening within the state.”

For food producers, processors, and manufacturers, the tool can be used to create plans for what areas of their operations are expected to be most at risk from the changing climate, she said. For farmers, the tool can be used to help rethink where to grow crops based on models showing, for example, expected increases in big rainstorms or average spring precipitation in their local area. For larger-scale food processors or manufacturers, the tool can help prioritize infrastructure and investment based on expected temperature, humidity, and precipitation over the next 15, 20, and 50 years across the various counties in Minnesota.

Black and her colleagues see the tool as part of a suite of tools that will generate more interest from food industry stakeholders in steps they can take to begin creating or advancing an adaptation plan to meet the changes in climate. “We also hope that more awareness of our tool across the country will help to demonstrate the need for other states to have access to downscaled climate data for climate planning,” she says.