title: Individual fumonisin exposure and sphingoid base levels in rural populations consuming maize in South Africa.
abstract: Low and high oesophageal cancer incidence areas of the former Transkei region of South Africa have been associated with corresponding low and high levels of fumonisin contaminated home-grown maize. This is the first study in South Africa assessing fumonisin B (FB) mycotoxin exposure by quantifying individual maize consumption with weighed food records and FB levels from maize in each participant's household and concurrently evaluating sphinganine (Sa), sphingosine (So) and Sa/So ratios in plasma and urine of these participants as possible biomarkers of FB exposure. The high consumption of maize in Bizana (n=36) and Centane (n=30) of 0.41+/-0.21 and 0.39+/-0.19 kg/day, respectively, confirms the reliance on maize as the dietary staple. Mean total FB (FB(1)+FB(2)+FB(3)) levels in home-grown maize were 0.495+0.880 and 0.665+0.660 mg/kg in Bizana and Centane, respectively. Mean fumonisin exposure based on individual consumption was 3.9+/-7.3 and 4.1+/-7.6 microg/kg body weight/day, respectively, for Bizana and Centane. The mean combined sphinganine/sphingosine ratios in Bizana and Centane were similar and ranged from 0.10-0.55 in plasma (n=41) and urine (n=62). There was no association between sphingoid base levels and/or Sa/So ratios in the plasma and urine and individual fumonisin exposure, negating the sphingoid bases as potential biomarkers of fumonisin exposure in humans.
authors.affiliation: PROMEC Unit, Medical Research Council, Tygerberg, South Africa. liana.van.der.westhuizen@mrc.ac.za
authors.forename: L
authors.initials: L
authors.lastname: van der Westhuizen
authors.forename: G S
authors.initials: GS
authors.lastname: Shephard
authors.forename: J P
authors.initials: JP
authors.lastname: Rheeder
authors.forename: H-M
authors.initials: HM
authors.lastname: Burger
mesh_terms: D037341:Fumonisins / Q000633:toxicity*; D006801:Humans; D009369:Neoplasms / Q000453:epidemiology; D012424:Rural Population; D013019:South Africa / Q000453:epidemiology; D003313:Zea mays
chemical_list: D037341:Fumonisins