title: Occurrence of aflatoxin M1 in urines from rural and urban adult cohorts in Bangladesh.
abstract: Aflatoxins are important mycotoxins produced by Aspergillus flavus and A. parasiticus, moulds which contaminate mainly grains and nuts, especially in hot and humid climate. Presence of aflatoxin B1 (AFB1), the most toxic one and a potent hepatocarcinogen, has been reported in food and feed in Bangladesh and raised concerns about mycotoxin exposure in the population. Biomonitoring provides the best approach to assess human exposure from various sources and by all routes. Part of the ingested AFB1 is converted in the body to aflatoxin M1 (AFM1), a metabolite that has served as biomarker of AFB1 exposure, as it is excreted in urine, and thus enables non-invasive sampling, a relevant aspect in field studies. This investigation measured the AFM1 concentration in urines collected from adult residents of a rural (n = 52) and an urban (n = 43) area in the Rajshahi district of Bangladesh. The urinary levels of AFM1 were determined by enzyme-linked immunosorbent assay. AFM1 was detected in 46 % of all urine samples at a range of 31-348 pg/mL. The median and mean concentration of AFM1 in urine was 61 and 80 ± 60 pg/mL, respectively. A significant difference (p < 0.05) was found at the mean level of AFM1 between the rural (99 ± 71 pg/mL) and urban (54 ± 15 pg/mL) cohort. Urinary AFM1 levels did not show significant correlations with food frequency data or age, gender and body mass index of the participants. Among them, the highest mean AFM1 level (101 ± 71 pg/mL) was observed in the 50-60 years age group. In conclusion, detection frequency and urinary AFM1 levels in the Bangladeshi adults support concerns regarding their dietary exposure to AFB1. These first data warrant further biomarker-based studies in children and in cohorts of other parts of the country.
authors.affiliation: Leibniz-Research Centre for Working Environment and Human Factors (IfADo) at the TU Dortmund, Ardeystr. 67, 44139, Dortmund, Germany. nali@ifado.de.
authors.forename: Nurshad
authors.identifier: http://orcid.org/0000-0003-1649-0887
authors.initials: N
authors.lastname: Ali
authors.affiliation: Department of Biochemistry and Molecular Biology, Rajshahi University, Rajshahi, 6205, Bangladesh.
authors.forename: Khaled
authors.initials: K
authors.lastname: Hossain
authors.affiliation: Leibniz-Research Centre for Working Environment and Human Factors (IfADo) at the TU Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.
authors.forename: Meinolf
authors.initials: M
authors.lastname: Blaszkewicz
authors.affiliation: Department of Biochemistry and Molecular Biology, Rajshahi University, Rajshahi, 6205, Bangladesh.
authors.forename: Mashiur
authors.initials: M
authors.lastname: Rahman
authors.affiliation: Department of Biochemistry and Molecular Biology, Rajshahi University, Rajshahi, 6205, Bangladesh.
authors.forename: Nayan Chandra
authors.initials: NC
authors.lastname: Mohanto
authors.affiliation: Department of Zoology, Rajshahi College, National University, Rajshahi, 6100, Bangladesh.
authors.forename: Abdul
authors.initials: A
authors.lastname: Alim
authors.affiliation: Leibniz-Research Centre for Working Environment and Human Factors (IfADo) at the TU Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.
authors.forename: Gisela H
authors.initials: GH
authors.lastname: Degen
mesh_terms: D000293:Adolescent; D000328:Adult; D016604:Aflatoxin B1 / Q000032:analysis* / Q000378:metabolism; D016607:Aflatoxin M1 / Q000652:urine*; D001459:Bangladesh; D015415:Biomarkers / Q000652:urine; D015331:Cohort Studies; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D005506:Food Contamination / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D012424:Rural Population / Q000706:statistics & numerical data*; D012621:Seasons; D014329:Tropical Climate; D014505:Urban Population / Q000706:statistics & numerical data*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D016607:Aflatoxin M1; D016604:Aflatoxin B1
keywords: Aflatoxin B1; Aflatoxin M1; Biomarker; Exposure; Mycotoxins