According to Gram Research analysis, toxic chemicals in food caused 6.26 million illnesses and 1.12 million deaths worldwide in 2021, with arsenic and lead responsible for nearly 9 out of 10 deaths. A WHO systematic review of data from 2000-2021 found that these nine foodborne chemicals created a substantial global disease burden, though the risk varies dramatically by region and age group.
A major World Health Organization study analyzed how nine toxic chemicals found in food—including arsenic, lead, and mercury—harm people worldwide. Researchers examined data from 2000 to 2021 and found these chemicals caused 6.26 million cases of illness, over 1 million deaths, and significant disability in 2021 alone. The study reveals that arsenic and lead are the biggest culprits, causing most deaths through heart disease. Different regions face different risks: South-East Asia struggles most with arsenic and lead, while children in the Americas are most affected by mercury. Understanding where these chemicals hide in our food supply is crucial for protecting public health.
Key Statistics
A 2027 WHO systematic review found that nine foodborne chemicals caused 6.26 million cases of illness, 1.12 million deaths, and 29.8 million disability-adjusted life-years globally in 2021, with inorganic arsenic and lead accounting for 88.9% of deaths.
According to the WHO’s 2027 analysis of foodborne chemical disease burden, South-East Asia experienced the highest regional impact with 789 disability-adjusted life-years per 100,000 people, primarily from arsenic and lead exposure.
A 2027 WHO data synthesis found that cardiovascular diseases caused by inorganic arsenic and lead accounted for 76.5% of the total disease burden from foodborne chemicals globally, making heavy metals the primary health threat.
The WHO’s 2027 systematic review identified that the Americas region had the highest foodborne chemical burden in children under 5 years old at 749 disability-adjusted life-years per 100,000 children, mainly due to methylmercury’s effects on brain development.
The Quick Take
- What they studied: How much illness and death nine toxic chemicals in food cause around the world, tracking changes from 2000 to 2021
- Who participated: This wasn’t a traditional study with human participants. Instead, researchers analyzed data from hundreds of previous studies, health records, and expert knowledge about how these chemicals affect people in different countries
- Key finding: In 2021, toxic chemicals in food caused 6.26 million illnesses, 1.12 million deaths, and affected 29.8 million people’s quality of life globally. Arsenic and lead were responsible for nearly 9 out of 10 deaths from foodborne chemicals
- What it means for you: The chemicals in this study are already being tracked by food safety agencies in many countries. While the numbers sound large, your risk depends on where you live, what you eat, and local food safety standards. This research helps governments improve food safety rules
The Research Details
The World Health Organization conducted a massive data synthesis, meaning they gathered and analyzed information from hundreds of scientific studies conducted over two decades. Rather than testing people directly, researchers used existing health data, scientific studies about how these chemicals harm the body, and computer models to estimate how many people got sick from nine specific toxic chemicals found in food.
The nine chemicals studied were: aflatoxins (mold toxins in nuts and grains), inorganic arsenic (a poison in some water and crops), lead (a heavy metal), methylmercury (a form of mercury), cadmium (another heavy metal), dioxin (an industrial chemical), peanut allergy reactions, and cassava cyanide (a toxin in cassava root). Researchers used mathematical models that account for differences between countries and tracked how the problem changed over 21 years.
The team combined information from dose-response studies (which show how much of a chemical causes harm), global disease data, and expert judgment to create estimates for every country and region. They calculated three main measures: how many people got sick, how many died, and how much illness reduced people’s quality of life (measured in DALYs—disability-adjusted life years).
This approach matters because toxic chemicals in food are a hidden health problem that’s hard to see. Unlike an outbreak you can track, chemical exposure happens slowly over time and affects different people in different places. By synthesizing decades of research, the WHO could show the true global scale of the problem and identify which chemicals and regions need the most attention. This helps governments decide where to invest in food safety improvements.
This study is a systematic review, which is one of the strongest types of research because it combines evidence from many sources. The WHO used established scientific methods and included uncertainty ranges in their estimates, showing they were honest about what they don’t know perfectly. However, the quality depends on the underlying data—some countries have better food safety monitoring than others, so estimates for less-monitored regions may be less precise. The researchers were transparent about these limitations.
What the Results Show
In 2021, the nine foodborne chemicals caused 6.26 million cases of illness worldwide, with a range of 3.36 to 10.30 million when accounting for uncertainty. These chemicals caused 1.12 million deaths (ranging from 400,000 to 2.1 million), making them a significant global health threat. The total burden measured in DALYs—a metric combining deaths and years lived with disability—reached 29.8 million globally.
Arsentic and lead were by far the most dangerous chemicals, causing 88.9% of all deaths from foodborne chemicals and 76.5% of the total disease burden. These two metals primarily caused heart disease and stroke, which are the leading causes of death from foodborne chemical exposure. This finding is important because it shows that the biggest health threat isn’t from exotic chemicals but from common heavy metals that contaminate water and crops.
The disease burden varied dramatically by region. South-East Asia had the highest rate of illness per person, with 789 DALYs per 100,000 people, mostly from arsenic and lead exposure. In contrast, the Americas had the highest burden in young children under 5 years old (749 DALYs per 100,000 children), primarily from methylmercury affecting brain development. This regional variation reflects differences in food sources, water quality, and industrial activity.
Dioxin showed the most improvement over the 21-year study period, with disease burden decreasing steadily from 2000 to 2021. This suggests that regulations limiting dioxin in food have been effective. Peanut allergies and cassava cyanide caused smaller portions of the overall burden but still affected millions of people, particularly in regions where these foods are dietary staples. The study found that different age groups faced different risks: children were particularly vulnerable to mercury’s effects on brain development, while older adults bore more of the burden from arsenic and lead causing heart disease.
This 2027 update builds on previous WHO estimates from earlier years. The new analysis includes more recent data and refined methods for calculating disease burden. The findings confirm what earlier research suggested: that heavy metals like arsenic and lead are the primary concern for foodborne chemical health impacts globally. The regional patterns identified in this study align with known differences in food safety infrastructure and environmental contamination levels across different parts of the world.
The study’s main limitation is that it relies on existing data, which varies in quality by country. Wealthy nations with strong food safety monitoring systems have better data, while developing countries may have less complete information, making estimates less precise for those regions. The researchers couldn’t directly measure how much of each chemical people actually consumed—they had to estimate based on food supply data and studies. Additionally, some chemicals’ health effects are still being researched, so the estimates may change as science advances. The study also couldn’t account for all possible sources of exposure, such as contaminated drinking water in some regions.
The Bottom Line
Food safety agencies should prioritize reducing arsenic and lead in food and water supplies, as these cause the most harm (high confidence). Regions with high exposure should invest in testing crops and water for contamination (high confidence). Pregnant women and young children should be particularly careful about mercury exposure from certain fish (high confidence). Most people in developed countries with strong food safety systems face relatively low risk from these chemicals (moderate confidence). Individual dietary changes are less important than systemic food safety improvements, though choosing diverse food sources can reduce exposure to any single contaminant (moderate confidence).
Everyone should care about this research because we all eat food, but the impact varies. People in South-East Asia and other regions with high arsenic and lead contamination face the greatest risk. Young children and pregnant women are especially vulnerable to mercury’s brain-damaging effects. People who eat large amounts of certain fish species (particularly predatory fish) may have higher mercury exposure. Conversely, people in developed countries with strict food safety regulations face much lower risk. Food safety officials, policymakers, and public health professionals should use this data to guide regulations and interventions.
Food safety improvements take time. Reducing contamination in crops and water supplies can take years or decades because it requires infrastructure changes and agricultural practice shifts. However, some improvements can happen quickly—for example, testing and removing contaminated batches of food can protect people within months. Individual health improvements from reduced chemical exposure would likely take months to years to become noticeable, as these chemicals cause chronic diseases that develop slowly over time.
Frequently Asked Questions
What toxic chemicals in food are most dangerous to my health?
Inorganic arsenic and lead are the most dangerous, causing 88.9% of deaths from foodborne chemicals globally according to the 2027 WHO analysis. These heavy metals primarily cause heart disease and stroke. Mercury is particularly dangerous for children’s brain development.
How much does food contamination with chemicals affect people worldwide?
The 2027 WHO systematic review found that nine foodborne chemicals caused 6.26 million illnesses and 1.12 million deaths in 2021 alone. The burden varies by region, with South-East Asia experiencing the highest rates due to arsenic and lead contamination.
Which regions have the biggest problems with toxic chemicals in food?
South-East Asia has the highest overall burden from foodborne chemicals, primarily from arsenic and lead in water and crops. The Americas has the highest burden in young children, mainly from mercury exposure affecting brain development.
Can I reduce my exposure to toxic chemicals in food?
Individual actions help but are less important than food safety systems. You can diversify protein sources to avoid concentrated exposure to any single contaminant, limit consumption of predatory fish high in mercury, and choose foods from regions with strong safety standards when possible.
Is the problem of toxic chemicals in food getting better or worse?
The 2027 WHO analysis shows mixed trends. Dioxin contamination has decreased significantly from 2000 to 2021 due to effective regulations. However, arsenic and lead remain major problems, particularly in developing regions with less food safety infrastructure.
Want to Apply This Research?
- Track weekly fish consumption by type (predatory vs. non-predatory species) and portion size to monitor mercury exposure. Users can log specific fish varieties and compare their intake against recommended limits based on their region and age group.
- Users can set a goal to diversify their protein sources, rotating between different fish species, plant-based proteins, and other meats to reduce cumulative exposure to any single contaminant. The app could suggest alternative foods based on regional contamination patterns.
- Implement a quarterly review feature where users assess their dietary patterns against regional food safety data. The app could provide personalized risk assessments based on location, age, and dietary habits, with recommendations for reducing exposure to the highest-risk chemicals in their area.
This article summarizes WHO research on foodborne chemical disease burden and is for informational purposes only. It does not constitute medical advice. Individual risk from foodborne chemicals depends on location, diet, age, and local food safety standards. If you have concerns about chemical exposure or health symptoms, consult a healthcare provider. Food safety regulations and recommendations vary by country—follow guidance from your local health authorities. Pregnant women, young children, and people with certain health conditions should discuss dietary concerns with their doctor.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.