Wheat grains are susceptible to contamination with various natural mycotoxins including regulated and emerging mycotoxins. This study surveyed the natural presence of regulated mycotoxins, such as deoxynivalenol (DON) and zearalenone (ZEN), and emerging mycotoxins such as beauvericin (BEA), enniatins (ENNs such as ENA, ENA1, ENB, ENB1) and Alternaria mycotoxins (i.e., alternariol monomethyl ether (AME), alternariol (AOH), tenuazonic acid (TeA), tentoxin (TEN), and altenuene (ALT)) in wheat grains randomly collected from eight provinces across China in 2021. The results revealed that each wheat grain sample was detected with at least one type of mycotoxin. The detection rates of these mycotoxins ranged from 7.1% to 100%, with the average occurrence level ranging from 1.11 to 921.8 µg/kg. DON and TeA were the predominant mycotoxins with respect to both prevalence and concentration. Approximately 99.7% of samples were found to contain more than one toxin, and the co-occurrence of ten toxins (DON + ZEN + ENA + ENA1 + ENB + ENB1 + AME + AOH + TeA + TEN) was the most frequently detected combination. The dietary exposure to different mycotoxins among Chinese consumers aged 4–70 years was as follows: 0.592–0.992 µg/kg b.w./day for DON, 0.007–0.012 µg/kg b.w./day for ZEN, 0.0003–0.007 µg/kg b.w./day for BEA and ENNs, 0.223–0.373 µg/kg b.w./day for TeA, and 0.025–0.041 µg/kg b.w./day for TEN, which were lower than the health-based guidance values for each mycotoxin, with the corresponding hazard quotient (HQ) being far lower than 1, implying a tolerable health risk for Chinese consumers. However, the estimated dietary exposure to AME and AOH was in the range of 0.003–0.007 µg/kg b.w./day, exceeding the Threshold of Toxicological Concern (TTC) value of 0.0025 µg/kg b.w./day, demonstrating potential dietary risks for Chinese consumers. Therefore, developing practical control and management strategies is essential for controlling mycotoxins contamination in the agricultural systems, thereby ensuring public health.

Deoxynivalenol (DON) and emerging Alternaria toxins often co-occur in cereal-based products, but the current risk assessment is commonly conducted for only one type of mycotoxin at a time. Compared to adults, infants and young children are more susceptible to mycotoxins through food consumption, especially with cereal-based food products which are the main source of exposure. This study aimed to perform a probabilistic risk assessment of combined exposure to DON and three major Alternaria toxins, namely including alternariol monomethyl ether (AME), alternariol (AOH), and tenuazonic acid (TeA) through consumption of cereal-based foods for Chinese infants and young children. A total of 872 cereal-based food products were randomly collected and tested for the occurrence of DON and three major Alternaria toxins. The results on mycotoxin occurrence showed the DON, TeA, AOH, and AME was detected in 56.4%, 47.5%, 7.5%, and 5.7% of the samples, respectively. Co-contamination of various mycotoxins was observed in 39.9% of the analyzed samples. A preliminary cumulative risk assessment using the models of hazard index (HI) and combined margin of exposure (MoET) was performed on DON and Alternaria toxins that were present in cereal-based food products for infants and young children in China for the first time. The results showed that only 0.2% and 1.5%, respectively, of individuals exceeded the corresponding reference value for DON and TeA, indicating a low health risk. However, in the case of AME and AOH, the proportion of individuals exceeding the reference value was 24.1% and 33.5%, respectively, indicating the potential health risks. In the cumulative risk assessment of AME and AOH, both HI and MoET values indicated a more serious risk than that related to individual exposure. Further research is necessary to reduce the uncertainties that are associated with the toxicities of the Alternaria toxins and cumulative risk assessment methods.

China is the world’s largest producer and consumer of aquatic products. Insecticides， as well as veterinary drugs， such as quinolones， macrolides， nitroimidazoles， sulfonamides， and amphenicols， are widely used in aquaculture. These compounds play crucial roles in preventing， controlling， and treating diseases in aquatic organisms， improving feed conversion rates， and promoting the healthy growth of farmed species. However， the illegal use of veterinary drugs， their overuse， and noncompliance with drug withdrawal periods by farmers can lead to aquatic products containing veterinary drug residues. This study focused on fish， shrimp， and crabs with the aim of meeting the green-development needs of China’s aquaculture industry， strengthening risk warnings and preventing veterinary drug residues in aquatic products， enhancing the quality and competitiveness of farmed aquatic products， and promoting the sustainable development of the aquaculture industry. Instrumental working conditions were optimized， and the extraction solvent， extraction method， purification materials， and the redissolution solvent used in the sample-pretreatment process were determined. These efforts led to the establishment of a protocol for the detection of 50 veterinary drug residues， including quinolones， macrolides， nitroimidazoles， sulfonamides， amphenicols， and insecticides， in fish， shrimp， and crabs， which involved one-step pretreatment with a composite purification column in combination with ultra-performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）. A 5-g sample was extracted with a 1.0% acetic acid solution， dehydrated with anhydrous sodium sulfate， and purified using a FAVEX purification column， after which the purified solution was nitrogen-blown to near dryness. The residue was re-dissolved in 1.0 mL of 0.2% formic acid aqueous solution-methanol （9∶1， v/v） ， filtered， and then separated using a Waters ACQUITY UPLC^® BEH C18 column （100 mm × 2.1 mm， 1.7 μm）. Data were collected in positive- and negative-ion multiple reaction monitoring modes， and quantified using isotopic internal and external standards. All target compounds exhibited good linear relationships within their respective concentration ranges， with coefficients of determination （R²） greater than 0.990 0. Average recovery rates of 60.1%–117.8% were determined for the 50 veterinary drugs in the fish matrix， with RSDs of between 1.89% and 15.0%， while the shrimp matrix delivered average recovery rates of 60.2%–119.7%， with RSDs of 1.11%–15.6%， and the crab matrix exhibited average values of 60.7%–119.7% and 2.94%–15.0%， respectively. The developed method is advantageous owing to its simple pretreatment step， high throughput， low organic-solvent consumption， good accuracy， high sensitivity， and cost-effectiveness. One hundred and fifty batches of aquatic products， including 50 batches of fish， 50 batches of shrimp， and 50 batches of crab， were risk-screened for 50 veterinary drug residues using the established detection method. Veterinary drug residues were detected at a rate of 47.3%， with an over-standard rate of 7.3%. Specifically， the fish samples exhibited a detection rate of 66.0%， with contamination concentrations of 1.20–257.1 μg/kg. In contrast， the shrimp samples exhibited a detection rate of 18.0%， with contamination concentrations of 1.10–8.60 μg/kg， while values of 22.0% and 3.00–7.30 μg/kg， respectively， were determined for the crab samples. This study identified a total of seven veterinary drug residues， namely pefloxacin， norfloxacin， ciprofloxacin， enrofloxacin， sarafloxacin， sulfadimethoxine， and sulfamethoxazole， with detection rates of 0.67%， 5.3%， 12.7%， 20.7%， 4.6%， 2.00%， and 1.33%， respectively. The detection method established in this study provides strong technical support for monitoring and assessing aquatic-product risks in a timely manner， and is expected play an important role in ensuring food safety， protecting consumer health， and promoting the healthy development of the aquatic-product industry.