Human exposures to mycotoxins through dietary intake are a major health hazard and may result in various pathophysiological effects. Although Thailand is a country at increased risk due to its climatic conditions, no comprehensive dataset is available to perform proper exposure assessment of its population with regard to mycotoxins. Therefore, this pilot study was conducted to investigate and evaluate the exposure levels of major mycotoxins (aflatoxin B₁, ochratoxin A, fumonisins, zearalenone and trichothecenes). Sixty first-morning urine samples were collected from healthy volunteers who live in the Bangkok metropolitan area and surrounding provinces (Pathumthani, Nonthaburi, Samutprakarn and Samutsakorn). Urine samples were analysed by a LC-MS/MS-based multi-biomarker method following a so-called 'dilute and shoot' approach. Results generally indicated low mycotoxin exposures in most individuals through the determination of the four biomarkers that were detected in urine samples, i.e. aflatoxin M₁, ochratoxin A (OTA), as well as the deoxynivalenol (DON) metabolites DON-3-glucuronide and DON-15-glucuronide in 10 of 60 individuals. The maximum concentrations were used to estimate the daily intake confirming that none of the individuals exceeded the tolerable daily intake (TDI) of DON (maximum 26% of TDI) or OTA (maximum 22% of TDI). However, the maximum exposure of aflatoxin B₁, estimated to be 0.91 µg (kg bw)⁻¹ day⁻¹, should raise some concerns and suggests further studies utilising a more sensitive method. Low exposure to Fusarium toxins was also confirmed by the absence of zearalenone, α-zearalanol, β-zearalanol and zearalenone-14-glucuronide as well as T-2 toxin, HT-2 toxin, nivalenol and free DON. This is the first multi-mycotoxin biomarker study performed in Southeast Asia.
Keywords: LC/MS/MS; Thailand; biomonitoring; exposure assessment; human urine; mycotoxin metabolite; xenobiotic.