# Occurrence, Distribution Characteristics, Risk Assessment, and Climatic Drivers of Type B Trichothecenes and Their Transformation Products in Major Wheat-Producing Areas of China

## TL;DR

This study examines the presence and health risks of mycotoxins in Chinese wheat, identifying climate factors and transformation products like DON-3G.

## Contribution

The study introduces new insights into DON-3G's role in mycotoxin exposure and links climate variables to contamination patterns in wheat.

## Key findings

- DON and DON-3G were the most common contaminants in Chinese wheat samples.
- Relative humidity, precipitation, and its duration during flowering-to-harvest were key climatic drivers of contamination.
- DON-3G contributed 23.5% to total DON exposure, highlighting its regulatory importance.

## Abstract

Type B trichothecenes (B-TCTs), predominant mycotoxins in wheat, threaten human health. However, their contamination profile in China, a major wheat producer, remains unclear. This study analyzed 1337 wheat samples (2022–2024) from main production areas using liquid chromatography-mass spectrometry and deterministic assessment to investigate B-TCTs’ watershed-scale distribution, spatiotemporal variations, associated health risks, and key climatic drivers. Results indicate that deoxynivalenol (DON) and its transformation product DON-3-glucoside (DON-3G) were the predominant contaminants, while nivalenol (NIV) was detected in specific river basins. Although overall exposure was low, elevated risks were identified in certain basins during particular years, especially for young children. DON-3G contributed 23.5% to total DON exposure. Relative humidity (rs = 0.34, p < 0.01), precipitation (rs = 0.37, p < 0.01), and its duration (rs = 0.38, p < 0.01) during the flowering-to-harvest period were identified as critical climatic drivers. The findings highlight the need to include DON-3G in food safety regulations and to develop climate-adapted control strategies.