A STUDY OF THE EXPOSURE OF A RURAL BLACK POPULATION TO FUNGI AND MYCOTOXINS AND THEIR POTENTIAL ROLE IN CHRONIC DISEASE

Abstract

ISEE-95 Introduction: A rural black community in the Tugela River Valley was chosen for an investigation into their exposure to fungi and mycotoxins. Two hundred households were studied and their location identified by geographic satellite positioning. Samples of food and stored food commodities were taken, and where feasible, biological specimens (blood, urine and faeces) were also sampled. Methods: The food materials were screened for fungi and mycotoxins, in particular fumonisin B1, which is associated with oesophageal cancer. Physiological samples were also analysed for fumonisin B1. The examination of faecal material for this toxin was of importance because it has been shown that most of this mycotoxin, fed to primates, ended up in the faeces. It was conjectured that this, therefore, could become a direct measure of the ingestion of the toxin in the previous 48 hours. Results: The results showed that the main food staple in this community was maize, much of which was home grown and that this contained, as expected, mainly Fusarium verticillioides and its mycotoxin, fumonisin B1. Fumonisin B1 was also found in blood and urine and, more significantly, at a fairly high frequency in the faeces. Discussion: It is apparent that although oesophageal cancer is not at a particular high incidence in this region, the population is routinely exposed to fumonisin B1 and other maize-borne toxins. This is not surprising as the population will eat maize as much as three times per day. Furthermore, the study area is in a rain shadow region and consequently local maize crops are not of high quality and are likely to become infected with F. verticillioides. The local population was warned directly, and also through local agricultural extension officers and health workers, against consuming mouldy maize.