Identifying and Understanding Emerging Toxins

The food we eat today faces threats from toxins that weren’t even on our radar a few decades ago. These emerging toxins-substances recently identified or increasingly prevalent due to industrial processes, environmental changes, and natural sources-pose new challenges to food safety. Understanding these contaminants is crucial for protecting public health as they appear in everything from drinking water to everyday groceries.

What makes a toxin “emerging”? 🔗

Emerging toxins differ from traditional food contaminants because they’re either newly recognized as health hazards or have become more widespread in recent years. Some arise from industrial chemicals that persist in the environment, while others come from natural sources amplified by climate change and modern agricultural practices. The National Institute of Environmental Health Sciences tracks these substances as they present evolving risks to human health, requiring updated detection methods and safety standards.

PFAS: the forever chemicals in our food supply 🔗

Per- and polyfluoroalkyl substances, commonly known as PFAS, represent one of the most concerning groups of emerging toxins. These synthetic chemicals have been used since the 1950s in products ranging from non-stick cookware to food packaging. PFAS include nearly 15,000 different compounds, and their extremely strong carbon-fluorine bonds make them virtually indestructible in the environment-hence the nickname “forever chemicals.”

Food contamination occurs when PFAS leach from packaging materials, contaminated water sources, or soil where food is grown. The FDA reports that seafood shows higher contamination rates, with 74% of tested samples containing detectable PFAS levels. Filter feeders like clams and oysters accumulate these chemicals more readily than other seafood types.

Health impacts of PFAS exposure 🔗

The health concerns surrounding PFAS exposure are substantial. Studies have linked these chemicals to increased cholesterol levels, high blood pressure during pregnancy, developmental issues, weakened immune response, liver function changes, and certain cancers. Because PFAS bioaccumulate in the body faster than they’re excreted, even low-level exposure over time can reach concerning concentrations. The widespread detection of PFAS in human blood samples-found in 93% of tested Americans-demonstrates how pervasive this contamination has become.

Microcystin: when algae blooms threaten food safety 🔗

Microcystins are toxic compounds produced by cyanobacteria, commonly known as blue-green algae. These toxins enter the food chain when algal blooms contaminate drinking water sources or when fish and shellfish consume contaminated water. The World Health Organization identifies over 200 variants of microcystins, each with different levels of toxicity.

Climate change and nutrient runoff from agricultural areas have increased the frequency and intensity of harmful algal blooms worldwide. These blooms release microcystins into freshwater systems used for drinking water and irrigation. The toxins are primarily hepatotoxic, meaning they damage liver cells, but they can also affect other organs and systems when consumed in contaminated food or water.

How microcystins affect human health 🔗

Acute microcystin poisoning can cause severe liver damage, while chronic low-level exposure raises concerns about long-term health effects. The toxins inhibit protein phosphatases, enzymes critical for cell regulation, leading to cellular dysfunction. Food safety authorities monitor microcystin levels in seafood, particularly in fish from affected water bodies, but detection remains challenging due to the numerous variants that can co-occur in contaminated products.

BPA: the endocrine disruptor hiding in packaging 🔗

Bisphenol A, widely known as BPA, is an industrial chemical used to manufacture polycarbonate plastics and epoxy resins. Found in food containers, water bottles, and the linings of canned goods, BPA leaches into food, particularly when containers are heated or contain acidic foods. This compound acts as an endocrine disruptor, mimicking estrogen and interfering with hormone function.

The primary route of human exposure to BPA is through diet. Canned foods typically show higher BPA levels than other food products because the chemical leaches from the protective epoxy lining designed to prevent metal corrosion. Studies have detected BPA in 93% of urine samples from people six years and older, demonstrating how widespread exposure has become.

BPA’s impact on health 🔗

Research links BPA exposure to numerous health concerns. The chemical can affect reproductive systems, potentially causing infertility in both men and women. It may contribute to early puberty in girls and has been associated with hormone-dependent cancers such as breast and prostate cancer. Metabolic disorders including obesity, diabetes, and polycystic ovary syndrome have also been connected to BPA exposure. Developing fetuses, infants, and young children face particular vulnerability because their bodies are growing rapidly and their detoxification systems are still maturing.

Pyrrolizidine alkaloids: natural toxins from plants 🔗

Pyrrolizidine alkaloids are naturally occurring plant toxins found in certain weed species that contaminate food crops during harvesting. More than 660 different PA structures have been identified, and approximately 120 of these are hepatotoxic. These compounds contaminate foods like honey, herbal teas, dried herbs, and grains when PA-containing plants grow alongside crops or when bees collect pollen from affected plants.

The contamination pathway varies by food type. Honey becomes contaminated when bees forage on PA-producing plants. Herbal teas and dried spices contain PAs when contaminating weeds are harvested with the intended crop. Small amounts of PAs can even transfer into milk, eggs, and meat when livestock consume contaminated feed.

Health risks from pyrrolizidine alkaloid exposure 🔗

PAs exhibit several toxic effects on the body. They are hepatotoxic, damaging liver cells and potentially causing cirrhosis with chronic exposure. Some PAs are classified as possible human carcinogens, raising concerns about long-term health impacts. They can also cause pneumotoxicity, affecting lung tissue, and show genotoxic properties that may damage DNA. Children, pregnant women, and nursing mothers face heightened risks from PA exposure due to their increased vulnerability to toxins.

Mycotoxins: fungal threats amplified by climate change 🔗

Mycotoxins are toxic compounds produced by certain fungi that grow on crops like grains, nuts, and spices. While not new to food safety, some mycotoxins are considered emerging threats because climate change is altering fungal distribution and increasing contamination risks. Rising temperatures, increased humidity, and extreme weather events create ideal conditions for toxigenic fungi to proliferate.

The most concerning mycotoxins include aflatoxins, ochratoxins, fumonisins, and various Fusarium toxins like deoxynivalenol. These compounds can remain stable during food processing and cooking, making them difficult to eliminate once contamination occurs. Emerging mycotoxins like alternariol, beauvericin, and enniatins are receiving increased attention as detection methods improve and their presence in food becomes better understood.

Why mycotoxins pose growing health concerns 🔗

Mycotoxins affect health in multiple ways depending on the specific toxin and exposure level. Aflatoxins are potent carcinogens linked to liver cancer. Ochratoxin A damages kidneys and may also be carcinogenic. Zearalenone acts as an endocrine disruptor, mimicking estrogen and causing reproductive problems. The FDA monitors these toxins in the food supply, but climate-driven changes in fungal ecology make contamination patterns less predictable and potentially more severe in coming years.

Moving forward: addressing emerging toxin risks 🔗

Understanding these emerging toxins represents the first step toward protecting food safety. Regulatory agencies worldwide are developing better detection methods, establishing safety limits, and monitoring contamination trends. Consumers can reduce exposure by choosing varied diets, properly storing foods to prevent fungal growth, avoiding damaged or moldy foods, and staying informed about contamination risks in their regions.

The challenge of emerging toxins requires coordinated efforts among farmers, food producers, regulators, scientists, and consumers. As our ability to detect these substances improves and our understanding of their health effects deepens, food safety practices must evolve to address these modern threats. Climate change, industrial practices, and agricultural methods will continue influencing how and where these toxins appear in our food supply, making ongoing vigilance essential.

What do you think? How can we better balance the benefits of modern food production and packaging with the need to minimize exposure to emerging toxins? What role should consumers play in driving change toward safer food systems?

References

1. https://www.niehs.nih.gov/health/topics/agents/pfc
2. https://www.fda.gov/food/process-contaminants-food/questions-and-answers-pfas-food
3. https://cdn.who.int/media/docs/default-source/wash-documents/wash-chemicals/microcystins-background-201223.pdf
4. https://www.niehs.nih.gov/health/topics/agents/sya-bpa
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC9671506/
6. https://pmc.ncbi.nlm.nih.gov/articles/PMC6032134/
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC10892171/
8. https://www.eea.europa.eu/en/analysis/publications/mycotoxin-exposure-in-a-changing-european-climate
9. https://www.fda.gov/food/natural-toxins-food/mycotoxins