Special Interview with Prof. Yongning Wu --The Head of World Health Organization (WHO) Collaborating Center of Food Contamination Monitoring (China)

Published on: 24 Oct 2023 Viewed: 1599

On 28 September, the Editorial Office of One Health & Implementation Research (OHIR) had the privilege of conducting a special interview with Prof. Yongning Wu, the head of World Health Organization (WHO) Collaborating Center of Food Contamination Monitoring (China). The interview focused on the theme of "Food Safety and Human Health: Chemical Contamination Monitoring and Risk Assessment." Additionally, our Editorial Board member, Prof. Marcello Iriti from Milan State University in Italy, took part in this special interview.

During the interview, Prof. Yongning Wu addressed the emerging issues of food contamination, perfluoroalkyl chemicals, and microplastics. He underscored the pivotal role of food safety in global food security and shared the latest achievements and international collaboration strategies of the National Food Safety Risk Assessment Center.

Personal Introduction:


Prof. Yongning Wu is the Chief Technical Officer at the National Food Safety Risk Assessment Center and Honorary Professor at Queen's University Belfast, United Kingdom. He also serves as the Co-Director of the Food Safety Innovation Unit at the Chinese Academy of Medical Sciences (2019RU4) and is the Director of a Key Laboratory at the National Health Commission. Furthermore, he holds the position of Director of the WHO Food Contamination Monitoring Collaboration Center in China, is a member of the WHO Food Safety Technical Advisory Group (TAG-Food Safety), and is a member of the WHO Strategic Advisory Group on Antimicrobial Resistance (STAG-AMR).

In 1983, he obtained a Bachelor's degree in Public Health from Nanjing Medical University (formerly Nanjing Medical College). In 1986 and 1997, he earned Master's and Ph.D. degrees in Nutrition and Food Hygiene from the former China Academy of Preventive Medicine, respectively. He has been honored with the National Award for Excellence in Innovation (2017) and has been recognized as a National Hundred and Thousand and Ten-Thousand Talent. In 2011, he received the Wu Jieping-Paul Janssen Medical & Pharmaceutical Award for Public Health. In 2018, he was elected as a Fellow of the International Academy of Food Science. In 2022, he was included in the "Top 100,000 Scientists Worldwide" lifetime scholars list. He has previously served as a Union for International Cancer Control Scholar at the WHO International Agency for Research on Cancer (IARC) and as a Royal Society Scholar at the Medical Research Council Toxicology Unit.

His primary research areas include food chemistry and pollution monitoring, with a focus on chemical contaminant monitoring, dietary exposure assessment, and high-throughput testing technologies for unexplained food poisoning incidents. He has conducted research on the detection of persistent organic pollutants (such as dioxins, polychlorinated biphenyls, brominated flame retardants, and perfluorochemicals) as well as food contaminants and illegal additives like chloropropanols, acrylamide, and clenbuterol. His work has led to the international recognition of trace and ultra-trace detection methods for important organic food contaminants in China. He has also played a key role in establishing a comprehensive set of national standards for screening, quantification, and confirmation. Notably, he has utilized exposure assessment research to develop national standards for food contamination and mycotoxins, and he has led the development of international food standards for inorganic arsenic limits in rice. He contributed to the formulation of the "WHO Global Food Safety Strategy 2022-2030", and has authored 15 books and published over 500 research papers.

Q1: What are the emerging food contaminants?

A: When we talk about emerging contaminants, it should be noted that these arise from the fact that previous detection technologies did not identify them in food, possibly due to their low concentrations and minimal associated risks. We have now discovered these substances, which have inadvertently entered food due to new food enhancement processes, posing significant health risks.

Last year, the General Office of the State Council of the People's Republic of China issued a plan for the management of emerging contaminants, outlining the major sources of ecotoxicity and performance-related pollutants among toxic and harmful chemicals, a matter of widespread concern both domestically and internationally. Currently, this action plan includes persistent organic pollutants regulated by international conventions, endocrine disruptors, antibiotics, and so on.

Based on the list of key controlled emerging contaminants released by China's Ministry of Ecology and Environment this year, these emerging pollutants in the environment have the potential to become emerging food contaminants through their migration along the food chain during the agricultural cultivation and breeding processes, as well as the later stages of food processing and storage.

Furthermore, with the advent of new food ingredients, particularly alternative protein sources, there is a shift in traditional food processing methods. Chinese President Xi Jinping has proposed the concept of a "big biological view," emphasizing the need for protein and energy from various sources, including animals, plants, microorganisms, forests, and oceans. Therefore, during our recent participation in various expert meetings held by the United Nations, we have been actively advocating for the replacement of traditional animal protein with alternative protein sources.

These alternative proteins can be derived from plant-based sources, precise fermentation, or cell cultivation. Consequently, these new food ingredients and production processes may introduce previously unknown health risks, which we refer to as "hazard concerned." For instance, at the Food Law Conference (FAO) in Singapore last year, I mentioned the topic of cell-cultured meat, for which the U.S. FDA issued a Letter of Non-Objection. We are continuously submitting relevant materials for approval, and once approved, companies can begin production. On November 2nd and 3rd this year, we will be participating in an international conference that primarily focuses on new food ingredients, especially alternative proteins, and we will place a specific emphasis on cell-cultured meat.

From the time of the Han Dynasty, when our ancestors made tofu, to the Song Dynasty's innovation of oil-processed gluten, the introduction of new raw materials and processing technologies has revolutionized food supply, shifting from agricultural production to industrialized production. This transformation has brought about various new contaminants in food processing, which have now become a major area of concern.

In this context, we are actively involved in addressing issues related to risk management and regulations. Following our participation in a series of expert meetings on FL and food safety held by the FBI, the U.S. Department of Agriculture, the European Union, and other international stakeholders, we are now heading to Rome to further develop FL guidelines for new food ingredients and food ecosystems.

In addition to this, we are also working on future technical guidelines for FAO with the World Health Organization (WHO) on basic production safety substances. This includes concerns related to cell-cultured meat, microplastics, microbial communities, microbiomes, and even the recycling of plastics. These changes in production systems can introduce new pollutants into the food supply, making food contaminants a complex and evolving issue. As a result, last year, the WHO made comprehensive revisions to its global food safety strategy.

Following these revisions, the WHO, in collaboration with the Food and Agriculture Organization of the United Nations, the World Organisation for Animal Health, and the United Nations Environment Programme, emphasized several critical gaps. Two of these gaps are relevant to our work. The first is food safety, emphasizing the need for coordinated mechanisms across multiple sectors, addressing foodborne diseases, and enhancing the capacity to apply One Health. The second gap concerns antimicrobial resistance and encompasses neglected infectious diseases, zoonotic diseases, and the impacts of environmental and climate change. Various driving forces will continue to introduce new food contamination challenges, such as climate change, which can increase humidity and introduce previously absent fungi or natural toxins into food. These issues are gradually becoming the focus of attention.

China's Ministry of Ecology and Environment has identified three major categories of emerging contaminants. The first category includes Persistent Organic Pollutants, which encompass a wide range of substances such as PCBs, historical pesticides like DDT, and compounds like PFAS (Per- and Polyfluoroalkyl Substances). PFAS not only pertain to production and usage but also impact various aspects of our lives, including pipelines and non-stick cookware. The second category pertains to Endocrine Disrupting Chemicals (EDCs). These are often found in materials that come into contact with food, such as food packaging materials, as well as in plastics used in machinery and pipelines for the transportation of food items like oils and beverages. There are plasticizers contained in plastics. The third category of concern is antibiotics. Our primary focus is on antibiotic resistance and the transmission of antibiotic resistance genes.

To summarize, when discussing emerging contaminants, there are various perspectives to consider. Currently, China's Ministry of Ecology and Environment has identified three major categories of emerging contaminants: persistent organic pollutants, endocrine disruptors, and antibiotics. These contaminants can originate from food packaging materials, plasticizers in food transportation machinery and pipelines, and antibiotics, with a primary focus on antibiotic resistance and the transfer of antibiotic resistance genes. Addressing all these challenges requires a One Health approach to research and resolution.

Q2: Can perfluoroalkylated substances (PFAS) pose a serious threat to human health?

A: The perfluoroalkyl chemical substances need a risk assessment to determine whether they pose a significant threat to human health. This is primarily because persistent organic pollutants are included in the new list of key controlled emerging contaminants released by China's Ministry of Ecology and Environment. Persistent organic pollutants have evolved over time, initially including chlorine, then bromine, and now fluorine, along with phosphorus compounds. Compounds containing fluorine are widely used in various applications, including non-stick cookware, cosmetics, and plastic pipelines.

In the past, it was generally believed that perfluorinated plastics were more durable than ordinary plastics and were better things, but the production of perfluoro compounds may involve methods such as polymerization or electrolysis, which was released into the environment.

Perfluorinated plastics serve as food contact materials, such as packaging and containers for edible oils, and pipelines used in food transportation; these substances are likely to migrate from the plastic. They are often referred to as "persistent organic pollutant" because they tend to remain in the body for extended periods. Unlike chlorine- and bromine-containing chemicals, which mainly accumulate due to their lipid-soluble characteristics, perfluoro compounds might not exhibit the same level of lipid solubility. However, they share similarities with fatty acids, with hydrogen atoms being replaced by fluorine atoms. Consequently, they behave more like fatty acids, which we consume through dietary fats. Fatty acids are known to bind to carrier proteins during metabolism, making them less easily excreted and potentially leading to their accumulation in the body. Therefore, whether a substance is harmful or not, its persistence in the body raises concerns.

At present, whether in the field of environment or food safety, perfluorinated compounds are actually a large class of substances, numbering possibly in the thousands. These compounds are a cause for concern due to their disruption of fatty acid metabolism, leading to various health risks that have garnered international attention. They have been found to have clear health risks, and perfluorosulfonic acids, especially perfluorooctane sulphonate (PFOS), have high levels of human exposure. Therefore, the production and use of these substances will be subject to the current national and international strict control, which can control the environmental emissions and pollution from the source, thereby reducing associated health risks. However, given the vast number of over a thousand different perfluoro compounds, their health risks need to be thoroughly examined. Research is required to determine how many of these compounds warrant attention.

Additionally, in-depth scientific analyses are needed to assess alternative products, as substituting one product for another does not necessarily guarantee greater safety. So, the study of perfluorinated compounds needs to take into account the environment and food, and in fact, we may also have to deal with veterinary ethics, epidemiology, and so on, calling for a collaborative approach employing the One Health approach.

Q3: Do microplastics represent a real global threat to food safety?

A: The health hazards of microplastics are not yet fully understood. As I mentioned earlier, microplastics are resulted from the breakdown of larger plastic items into smaller items, with varying sizes, shapes, and chemical polymer types. The combined complexity of these three aspects makes it difficult to assess the exact risks they pose to human health. Microplastics are commonly defined as plastic particles less than 5 mm in size and can be classified as primary and secondary microplastics.

In practice, the visible harm caused by microplastics is primarily observed in the ecosystem, particularly in aquatic life such as fish and shellfish. Microplastics can obstruct their gills and digestive systems, leading to observable harm within these species. However, the direct impact of microplastics on humans is hard to establish because it involves nanoscale particles, particle shape, and composition. FAO has published a systematic review on microplastics, and the China National Natural Science Foundation has initiated a key program that encompasses research on microplastics in terms of their morphology, analytical methods, and toxicity of microplastics.

Before we can figure out the specific hazards of microplastics, we first need to know the health outcomes caused by microplastics, and then determine the dose-response relationship based on the health outcomes. However, achieving this goal is currently difficult.

There are mainly three aspects related to the hazards of microplastics. The first aspect is the physical hazards posed by microplastics, which are related to size, shape, and composition. The second aspect is the chemicals adsorbed by microplastics and the additives used in their manufacturing process. The third aspect is that biomembranes can form on the surface of microplastics, and bacteria in the biomembranes can carry genes for antibiotics and drug resistance.

At present, we still don't know the safe dose for humans. In addition, it is not yet possible to accurately quantify exposure to microplastics, although they are ubiquitous in the environment and have been detected in various food and beverages, including fish and seafood, salt, sugar, honey, rice, milk, and drinking water. The limited available data prevented the assessment of the overall health risks of microplastics. Current information on dietary exposure to microplastics suggests that they may have adverse effects similar to those of other insoluble particles. These effects include the generation of reactive oxygen species and the stimulation of inflammatory responses.

It is hard to say if microplastics are a risk to food safety, but it is more appropriate to say it is "a hazard concern". We are concerned about this hazard, but a hazard is not a risk. Risk assessment requires the establishment of health-based guidance value, but we have not yet uncovered such value. This is still a topic under active research, and it necessitates the “One Health” approach to comprehensively study this issue.

Q4: The world population is rapidly increasing, with increasing malnutrition, in the context of climate change and globalization. In this complex scenario, what is the contribution of food safety to global food security?

A: Food safety and food security are two aspects that need to be balanced. If the requirements for food safety go beyond normal health standards, it can jeopardize the food supply. Currently, there is a preference for organic food. What is the yield of organic food? It's far from the quantities we could harvest in ancient times when we could gather 1000 pounds of grains, as today we can only collect 50 pounds. This situation clearly raises concerns about food security. Therefore, the demands of food safety should be moderate, and moderation implies taking measures to protect food from pests, which necessitates the use of pesticides. We also require animal medicines for treating livestock diseases, including antibiotics. Consequently, the modern agricultural process inevitably leads to pesticide and veterinary drug residues. From the perspective of food safety, we must examine the significance and toxicity of these pesticides and veterinary drugs, including their parent compounds and their metabolites, known as residues.

These residues need to be evaluated to determine the acceptable daily intake (ADI). This is distinct from pollutants, as we intentionally add pesticides, veterinary drugs, and food additives. We thus call it the acceptable daily intake (ADI), whereas for pollutants, we endure their presence, which we call Tolerable Daily Intake (TDI). Thus, the residues in the food must not exceed the ADI, or else the product cannot be registered for use.

So, according to national approvals, a specific veterinary drug or pesticide, produced within certain safety production intervals, is considered safe. In this way, food safety ensures that at least 30% of food is protected from pests and animal diseases. If food safety standards become excessively strict, it may not support this equilibrium. Therefore, food safety and food security complement each other, striving for an ideal health protection level (IOP) that guarantees food security.

Chinese people have always cited two key figures. When we first gained independence, life expectancy was around 35 years. Through food safety and healthcare, our life expectancy has now reached nearly 80 years. Food safety plays a critical role in protecting us from disease, and that is the first point.

In terms of reproductive health incidence, it can be classified into four tiers. Western countries are in the first tier, while Sub-Saharan Africa is in the fourth. Many other countries fall into the third tier. China's GDP falls into the third tier. However, according to the United Nations, our reproductive health incidence places us in the second tier. In terms of reducing reproductive health issues globally, as the World Health Organization's primary assessment indicator in its food safety strategy last year, it’s required to reduce by 40%. In this regard, when we look at China's reproductive health incidence and its GDP ranking, China seems to have made progress. So, it's fair to say that the Chinese government has performed quite well in the global context of food safety. Of course, we may not reach the economic level of first-world developed countries because, even with substantial investments in money and effort, developed countries may have slightly better control over reproductive health issues. This is an objective and fair assessment.

Q5: What are the latest achievements of the China National Center for Food Safety Risk Assessment in the field of chemical contamination monitoring and risk assessment, particularly any significant findings in recent years?

A: The illegal addition of melamine was found in animal feed in 2007. Subsequently, the government introduced a slogan of "twelve 100%" for food safety. However, it's important to note that there is no such thing as 100% risk-free food safety. We need to prioritize the scientific approach. The risk assessment is scientific, so after the completion of the “twelve 100%”, there were still urinary stones in 300,000 infants in 2008 due to melamine. Therefore, this incident has made our country reflect deeply after suffering, pay attention to scientific risk assessment and supervision in accordance with international rules, as well as the functional separation between risk assessment and risk management.

The process of risk assessment involves various steps, starting with hazard identification, then conducting hazard characterization, such as developing  health-based guidance values, followed by exposure assessment, and concluding with a risk characterization to determine the level of risk and how to control it.

To carry out this scientific risk assessment, we require data, and it's essential to establish a national risk monitoring plan. As a result, the China National Center for Food Safety Risk Assessment (CFSA) has a dedicated department for risk monitoring, which covers both foodborne diseases in humans and food safety. Once the data is collected, it is evaluated for potential hazards. After risk assessment, the final stage of risk management involves setting standards, including both maximum limits and production regulations. To support these activities, CFSA operates Research Center for Calibration & Applied Technology, comprising laboratories of chemistry, microbiology and toxicology, and has Department of Risk Surveillance with Division I and Division II for food and foodborne disease surveillance, respectively.

Our risk assessment is divided into three parts, with the first two parts being the risk assessment of food microbiology and food chemistry, respectively. The Expert Committee for Food Safety Risk Assessment is further divided into subcommittees specializing in chemical and microbial hazards. Additionally, we handle assessments for new food ingredients and food additives through a declaration system, considering factors like new varieties, expanded usage, and usage amounts. Ultimately, the results are announced by the National Health Commission, which determines what can and cannot be used in food products, taking into account traditional Chinese medicine and other considerations. We have a variety of traditional Chinese medicines. We have the concept of "food and medicine sharing the same origin," where items like jujubes and wolfberries are considered. On the other hand, there are newer Chinese medicines, such as ginseng. If ginseng is cultivated for less than five years, it's treated like a food product, similar to carrots. Therefore, we address such issues through assessment.

Based on this framework, with legal authorization, we have a National Expert Committee for Food Safety Risk Assessment. Under this committee, there's a Chief Technical Officer (CTO) and four subcommittees. The first subcommittee is responsible for monitoring plans, the second focuses on chemical hazards, the third is dedicated to microbial hazards, and the fourth deals with product assessments. After this process, we have the Review Committee for National Food Safety Standards. This committee is involved in administrative functions, comprising members from the National Health Commission, the State Administration for Market Regulation, the Ministry of Agriculture, and other relevant government bodies. The committee's office, often referred to as the Secretariat, is led by the respective regulatory authorities, and the Chairman of the Committee is usually a minister from one of these government departments. Beneath these bodies, CFSA carries out the functions of the Secretariat's office. We handle assessment tasks and translate them into standards.

In this context, our country has strived to create and integrate national standards across various sectors. This standardization process also aligns with international standards, and as a major player in the global food trade, we aim to contribute to one-third of international standards. Food safety has evolved as a primary concern, from addressing nutritional deficiencies to ensuring food safety and, finally, to preventing diseases through healthy eating. "Healthy China 2030" emphasizes the importance of a balanced diet and physical activity, focusing on areas such as salt, sugar, and fat consumption, as well as other aspects of nutrition. So, we have a National Nutrition Action Center.

CFSA has a Department of Risk Communication that disseminates information to the public and handles risk communication. To better assist with various tasks such as monitoring and assessment, we have an Information Technology Section to deal with this aspect. As the world transitions to Industry 4.0, food safety regulation is also advancing into a smarter era.

The National Expert Committee for Food Safety Risk Assessment and the Review Committee for National Food Safety Standards are equipped with experts spanning medical, agricultural, food, nutrition, environmental, and biological sciences, ensuring interdisciplinary collaboration. We operate through a One Health approach and participate in the Multisectoral Coordination Mechanism of the United Nations. This mechanism evaluates three indicators as part of its global strategy for food safety: an impact of reducing foodborne diarrhoeal disease by 40%, the worldwide reach of a score between four and five for multisectoral collaboration on food safety events, and a significant enhancement of surveillance capabilities for foodborne disease and food contamination to a score of 3.5 or above.

In this process, I also serve as the head of the NHC Key Laboratory of Food Safety Risk Assessment, the Food Safety Research Unit of Chinese Academy of Medical Science, and the World Health Organization Collaborating Centre for Food Contamination Monitoring. This collaboration is essential as food safety is a global issue that requires international cooperation to address it effectively.

Q6: As the head of the World Health Organization (WHO) Collaborating Center of Food Contamination Monitoring (China), how do you facilitate international cooperation to improve global standards and methods for food safety and chemical contamination monitoring?

A: The World Health Organization updates the global food safety strategy every ten years, which was recently updated. Two decades ago, my mentor, Academician Junshi Chen, led the expert advisory group for the food safety strategy. After the emergence of COVID-19, Chinese President Xi Jinping proposed the concept of "a global community of health for all". In 2020, at a conference, it was requested to revise the global food safety strategy.

To accomplish this, we rely on INFOSAN (the FAO/WHO International Food Safety Authorities Network) information reporting system, the FERG (The Foodborne Disease Burden Epidemiology Reference Group), and various international risk assessment expert committees, including the JECFA (Joint FAO/WHO Expert Committee on Food Additives) for additives, contaminants, mycotoxins, and veterinary drug residues, JMPR (Joint FAO/WHO Meeting on Pesticide Residues), JEMRA (Joint FAO/WHO Expert Meetings on Microbiological Risk Assessment), and a series of specialized working groups. This forms one level of cooperation.

The second level relies on the approximately 12 existing WHO international collaboration centers for food safety, zoonotic diseases, and infectious diseases. These collaboration centers should play a leading role. WHO's collaboration centers are divided into categories such as risk assessment, chemical hazards, and microbial hazards. For example, the RIVM (National Institute for Public Health and the Environment) in the Netherlands excels in chemical hazard databases and scientific models, while Institut Pasteur in France specializes in microbiology like Listeria. Technical University of Denmark excels in antimicrobial resistance, and Utrecht University in the Netherlands specializes in campylobacter. In the Americas, the U.S. CDC (Centers for Disease Control and Prevention) for Salmonella and the U.S. NSF International for aquatic diseases are significant.

In the Asia-Pacific region, there are still three, with two in China, and another being the newly established Singapore Food Agency. In Hong Kong, there is a Collaboration Center for Risk Analysis of Chemicals in Food. The collaboration centers undergo evaluation every four years based on their work performance, determining their future roles. Our collaboration center, for instance, has three TOR (Terms of Reference), the first being to provide training and support in terms of testing facilities, standard operating procedures, and training for food-related activities within the West Pacific region.

Secondly, it involves supporting the WHO's leadership role in global data collection, which is crucial for establishing standards. This data collection is facilitated by the Global Environmental Monitoring System/ Food Contamination Monitoring and Assessment Programme,  commonly known as GEMS/Food, which is a key component. In addition to the 12 WHO collaboration centers we mentioned earlier, several countries such as Japan, Vietnam, and Malaysia have their national GEMS/Food contact points for data reporting. For us, CFSA provides technical support to the NGCs (National GEMS/Food Centers) in China and capacity-building within the West Pacific region. This ensures that member countries base their policy and standard-setting decisions on evidence-based data collection.

Thirdly, our collaboration center leads in submitting data and training others on data submission. We also provide technical support and expertise in risk assessment and total diet studies (TDS) within the Asian region. Few countries conduct total diet studies, and China has conducted TDS six times, soon starting the seventh. This kind of research supports the establishment of risk assessment bodies within countries like Vietnam, which have recently expressed interest in setting up their national risk assessment institution, drawing upon our experiences and best practices.

In this entire process, each area, including antimicrobial resistance, POPs (persistent organic pollutants) testing, foodborne disease surveillance, risk assessment and standards, operates according to WHO's Activity ID and description.

It includes the link to three TORs, the concrete actions taken by the collaboration center, WHO’s role in this activity, expected deliverables, and evaluation criteria. Every year, there is an annual report, and every four years, a comprehensive report that assesses their performance. Some centers cease to exist if they do not meet their obligations after evaluation. However, since our inception in 1981, we have gone through four terms of center directors. Therefore, it is safe to say that we maintain a certain level of international influence and are still in operation.

As mentioned earlier, we discussed the global food safety strategy, and Member States need to develop country implementation road maps and submit them to the WHO. This task also requires technical support, and Collaboration Centers play a pivotal role in this regard, bearing significant international responsibilities on behalf of the major nations.

Editor: Zoe Xue
Language Editor: Catherine Yang
Production Editor: Kenny Wu
Respectfully Submitted by the Editorial Office of One Health & Implementation Research

One Health & Implementation Research
ISSN 2769-6413 (Online)


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