Pesticide residues and dietary health risks in onion marketed in Türkiye using deterministic and probabilistic approaches
This study analyzed 120 onion samples from Türkiye for 222 pesticide residues and, using both deterministic and probabilistic risk assessments, concluded that while residues were frequently detected, all levels remained well below safety thresholds, indicating a low dietary health risk for both adult and child consumers.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Every day, millions of people around the world reach for the humble onion, a vegetable that forms the backbone of countless meals and offers a wealth of nutrients. Because these crops are so valuable and so widely eaten, farmers must protect them from insects and diseases that can destroy the harvest. To do this, they often use chemical sprays known as pesticides. While these tools are essential for growing enough food, they can sometimes leave tiny traces behind on the vegetables we buy. The question for scientists and regulators is not just whether these traces exist, but whether the amount a person eats over a lifetime, or even in a single large meal, poses a danger to their health. To answer this, researchers look at two main things: how much of the chemical is actually on the food, and how much of that food a typical person consumes. They compare these numbers against strict safety limits set by health authorities to see if the exposure is safe or if it crosses a line where worry is justified.
In a recent study focused on the onion markets of Türkiye, a team of researchers set out to take a fresh, detailed look at this issue. They collected 120 onions from supermarkets and local markets across four different provinces, ensuring the samples represented a wide cross-section of what consumers actually buy. Instead of looking for just one or two common chemicals, the team screened the onions for a massive list of 222 different pesticide residues. They used highly sensitive laboratory equipment capable of detecting even the tiniest specks of these substances. The goal was to create a clear picture of what is currently on the onions in Türkiye, how often these chemicals appear, and whether the levels found would be harmful to adults or children who eat them regularly.
The results painted a reassuring picture. The researchers found that about one-third of the onions they tested contained detectable traces of pesticides. However, in every single case, the amount of chemical found was well below the strict safety limits established by the European Union. This means that while the chemicals were present, they were not at levels that would violate food safety regulations. The study also revealed that when onions did contain pesticides, they often contained more than one type at the same time. In fact, nearly three-quarters of the onions with any residue had a mix of two or more different chemicals. The most common substance found was a fungicide called boscalid, which appeared in nearly 30 percent of the samples, followed by two other chemicals, fluopyram and pyrimethanil.
To understand what this means for a person's health, the scientists went beyond simply counting the chemicals. They calculated the potential risk by imagining how much of these onions an average adult and an average child would eat over a long period, as well as how much they might eat in a single day. They used two different methods to be sure of their findings. The first method took a conservative approach, assuming the worst-case scenario where every onion contained the highest amount of residue found in the study. Even under this strict assumption, the estimated exposure for both adults and children was extremely low. The second method used advanced computer simulations to model thousands of different eating habits and residue levels, accounting for the natural variation in how much people eat and how much pesticide might be on different onions. Both methods led to the same conclusion: the risk of harm from eating these onions is negligible.
The study also highlighted an important lesson about how we interpret food safety data. While boscalid was the most frequently found chemical, it was not the biggest contributor to the overall risk. Instead, the chemicals fluopyram and pyrimethanil, which appeared less often, were the main drivers of the calculated risk because of their specific properties and the amounts found. This shows that simply counting how often a chemical appears is not enough to judge safety; one must also consider how much of it is there and how toxic it is. Ultimately, the research confirms that the onions currently sold in Türkiye are safe to eat. The levels of pesticide residues found do not pose a threat to the health of consumers, whether they are adults or children, and the findings support the continued monitoring of these crops to ensure they remain safe for everyone.
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