Supplementary materials for World Mycotoxin Journal: <b>Assessment of urinary biomarkers of mycotoxin exposure in adults from Cameroon</b>

<p dir="ltr">In Cameroon, dietary staples are frequently contaminated with diverse toxic fungal metabolites, known as mycotoxins. Aflatoxins and fumonisins are a public health concern, particularly concerning cancer and/or early life stunting. Mycotoxin mixtures are predicted from food measures; and this study reports the levels and frequencies of urinary mycotoxin biomarkers in Cameroonian adults. A single first void urine sample was collected from 89 adults from Yaoundé, Cameroon. Urine samples were tested for eight distinct mycotoxins using measures of both parent compounds and/or their metabolites by l<b>iquid chromatography</b> <b>tandem mass spectrometry (LC-MS/MS)</b>. Altogether, seven distinct mycotoxins, aflatoxin, fumonisin, deoxynivalenol, zearalenone, nivalenol, ochratoxin A and citrinin, (or their metabolites) were observed in urine samples. At least one mycotoxin was detected in all of the urine samples, 87 (98%) of which were above the limit of quantitation. Aflatoxin M₁ was detected in 42% (n.d.-0.21 µg/l) of samples of which about a quarter additionally contained fumonisin B₁. Of the remaining toxins deoxynivalenol (78%), zearalenone (99%), ochratoxin A (95%), nivalenol (53%) and citrinin (87%) were present in the samples. Alternariol was not detected in any sample. Mixtures of mycotoxins in the samples were frequently observed with 64 samples (72%) containing more than five mycotoxin exposure biomarkers. Estimates of intake exceeded the TDIs for fumonisin B₁ (n=4), deoxynivalenol (n=1) and zearalenone (n=2), no TDI is set for aflatoxin. This study reveals frequent co-exposure of Cameroonian individuals to a complex mixture of toxic and carcinogenic mycotoxins, with mixtures of aflatoxin and fumonisin being a particular priority from a public health standpoint.</p>