Researchers tested urine samples from 311 people living in three different regions of China to measure exposure to mycotoxins—harmful substances produced by molds that grow on crops. They found that most people had traces of at least one mycotoxin in their bodies, with some people exposed to dangerous levels. The study shows that where you live and what you eat affects how much of these toxins you’re exposed to. This research helps scientists understand how common this problem is and what health risks it might pose to different populations.

The Quick Take

  • What they studied: How much mold poison (mycotoxins) people have in their bodies based on where they live and what they eat in China
  • Who participated: 311 healthy adults from three different Chinese provinces: 103 from Anhui, 102 from Henan, and 106 from Sichuan. These areas have different climates and food cultures.
  • Key finding: Nearly two-thirds of people tested had unsafe levels of at least one mycotoxin in their urine, with deoxynivalenol (DON) being the most common. About 61% of people exceeded safe exposure limits for this toxin alone.
  • What it means for you: If you eat foods that may contain mold toxins, this research suggests the risk is real and widespread. However, this study doesn’t prove these toxins are currently making people sick—it only shows exposure levels. Talk to your doctor if you have concerns about food safety.

The Research Details

This was a snapshot study where researchers collected urine samples from 311 healthy volunteers across three Chinese provinces at one point in time. They used advanced laboratory equipment (UHPLC-MS/MS) to measure seven different mycotoxins in the urine—essentially looking for traces of mold poisons that people had eaten. The three provinces were chosen because they have different climates and people eat different foods, allowing researchers to see if geography and diet affect mycotoxin exposure.

The researchers then calculated how much mycotoxin each person was probably eating daily based on the amounts found in their urine. They compared these amounts to safety guidelines to determine if exposure levels were concerning. They also looked at whether people were exposed to multiple mycotoxins at the same time, which could increase health risks.

Understanding real-world exposure to mold toxins is important because these substances can accumulate in the body over time. By measuring actual exposure in different populations, researchers can identify which regions and dietary patterns pose the greatest risk. This information helps public health officials create better food safety standards and helps people make informed choices about what they eat.

This study has several strengths: it used precise laboratory methods to detect toxins, included people from three different geographic areas, and measured multiple toxins at once. However, it’s a snapshot in time rather than following people over months or years, so we don’t know if exposure levels change seasonally or with different harvests. The study also doesn’t prove that these toxin levels are currently causing health problems—it only shows exposure exists.

What the Results Show

The most striking finding was that deoxynivalenol (DON), a toxin from moldy grains, was found in 100% of urine samples, meaning every single person tested had been exposed to it. The average amount was 90.77 nanograms per milliliter of urine. When researchers compared this to safety guidelines, about 61% of people had levels considered potentially unsafe.

Other mycotoxins were less common but still concerning: zearalenone (ZEN) appeared in about 6% of samples, nivalenol (NIV) in about 25%, and aflatoxin M1 (AFM1) in about 11%. The good news is that fewer people exceeded safe limits for these individual toxins—less than 1% for ZEN and about 11% for NIV.

The most important finding was that most people (64%) were exposed to multiple mycotoxins at the same time. The most common combination was DON plus ZEN together, found in 46% of samples. When researchers looked at the combined risk of multiple toxins together, the numbers became more concerning: about 61% of people with the DON-ZEN combination exceeded safe limits, and 70% of those with three toxins together exceeded safe limits.

The study found differences between the three provinces, suggesting that local climate and food sources affect exposure levels. This indicates that mycotoxin contamination is not evenly distributed across China and that regional food production practices matter. The research also identified specific patterns of which toxins tend to appear together, which could help predict exposure risks in different areas.

This is the first study to comprehensively measure multiple mycotoxins in urine samples across different Chinese regions simultaneously. Previous research has looked at individual toxins or food contamination, but this study provides a more complete picture of actual human exposure. The findings align with concerns raised in other countries about mycotoxin contamination in grain-based foods.

This study has important limitations to consider. First, it’s a snapshot—researchers measured toxins at one point in time, so they can’t tell if exposure changes with seasons or food harvests. Second, the study only included healthy volunteers, so results may not apply to children, elderly people, or those with health conditions. Third, while the study shows exposure exists, it doesn’t prove these toxin levels are currently making people sick or what long-term health effects might occur. Finally, the study is limited to China, so results may not apply to other countries with different food systems.

The Bottom Line

Based on this research, consider these practical steps: (1) Vary your grain sources and don’t rely on one type of grain exclusively, as different crops may have different contamination patterns. (2) Store grains properly in cool, dry places to prevent mold growth. (3) If you live in areas with high humidity, be extra careful about food storage. (4) Support food safety regulations and testing programs in your region. Confidence level: Moderate—this study shows exposure exists but doesn’t yet prove it’s causing health problems.

Everyone should be aware of this research, especially people who eat a lot of grain-based foods, parents concerned about children’s food safety, and people living in humid climates where mold grows easily. People with weakened immune systems should be particularly cautious. However, this study doesn’t mean you should panic or completely avoid grains—it means being aware and taking reasonable precautions.

This research doesn’t address how quickly health effects might appear. Mycotoxins accumulate slowly in the body over time, so any health impacts would likely develop over months or years of exposure, not days or weeks. If you make dietary changes based on this research, give them at least several months to potentially show benefits.

Want to Apply This Research?

  • Track your grain and food sources daily, noting the type of grain (wheat, corn, rice, etc.), brand, and storage conditions. Rate perceived digestive comfort on a 1-10 scale to monitor any patterns between food sources and how you feel.
  • Implement a ‘grain rotation’ strategy: use 3-4 different grain sources each week instead of relying on one brand or type. Store all grains in airtight containers in cool, dry places. Log which grains you’re using and where they’re stored to build awareness of your food sources.
  • Over 3-6 months, track any changes in digestive health, energy levels, or general wellness as you rotate grain sources and improve storage. Use the app to identify patterns between specific grain sources and how you feel, helping you make informed choices about which products work best for your body.

This research shows that mycotoxin exposure is common in certain populations, but it does not prove that current exposure levels are causing illness in these individuals. This study measures exposure, not disease. If you have specific health concerns related to food contamination or mold exposure, consult with your healthcare provider or a registered dietitian. Do not use this information to self-diagnose or treat any medical condition. This summary is for educational purposes only and should not replace professional medical advice.