Background In Cameroon dietary staples are contaminated with diverse toxic fungal metabolites, known as mycotoxins. Aflatoxins and fumonisins are of particular public health concern, particularly in relation to cancer and/or early life stunting. Mixtures of these toxins are predicted from food measures, and in this work, the levels and frequencies of urinary mycotoxin biomarkers are reported in Cameroonian adults. Methods A single first void urine sample was collected from 89 adults (aged

more »

... 28–85, male 39, female 50) from the city of Yaoundé, Centre Region, Cameroon. Urines were tested for eight distinct mycotoxins using measures of both parent compounds and/or their metabolites by Liquid Chromatography tandem mass spectrometry (LC-MS/MS). Results 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 (97.8%) of which were above the method's quantification limit. Aflatoxin M1 was detected in 42% (n.d. − 0.21 µg L− 1) of samples of which about a quarter additionally contained fumonisin B1. Of the remaining toxins deoxynivalenol, zearalenone, ochratoxin A, nivalenol and citrinin were present in 78%, 99% 95%, 53%, and 87% of the samples respectively. Alternariol was not detected in any sample. Mixtures of mycotoxins in the samples were frequently observed with 64 samples (72%) containing more than five mycotoxins. Estimates of intake exceeded the TDIs for fumonisin (n = 4), deoxynivalenol (n = 1) and zearalenone (n = 2), no TDI is set for aflatoxin. Conclusions This study reveals frequent co-exposure of Cameroonian individuals to a complex mixture of toxic and carcinogenic mycotoxins, with mixtures of aflatoxin and fumonisin a particular priority from a public health standpoint.