title: Determination of aflatoxin M1in urine samples indicates frequent dietary exposure to aflatoxin B1in the Bangladeshi population.
abstract: Aflatoxin B1(AFB1), a hepatocarcinogen and highly toxic mycotoxin, is a contaminant of food commodities, especially in hot and humid climates that favour the growth of aflatoxin-producing fungi. As data on AFB1contamination of food and feed in Bangladesh are scarce, we conducted an initial screening by ELISA on the occurrence of the metabolite and biomarker aflatoxin M1(AFM1) in urines from Bangladesh which indicated frequent exposure. This finding led us to conduct a follow-up study where we applied a more sensitive method (IAC clean-up and HPLC-FD analysis) to determine AFM1concentrations in a larger set of urine samples. To account for possible seasonal and regional differences in mycotoxin exposure, in total 218 urines were collected in two districts of Bangladesh: 164 urines (n=69 in summer, n=95 in winter) from residents of a rural and an urban area in Rajshahi district, among them 62 participants enrolled in both sampling periods, and 54 urine samples obtained from pregnant women in Dhaka district. AFM1was detected in>40% of all Rajshahi urine samples at a range of 1.7-104pg/mL in summer and at a range of 1.8-190pg/mL in winter season. The mean level of urinary AFM1was higher in winter (27.7±42.6pg/mL) than in summer (13.6±21.2pg/mL) season, and differences were observed at the mean AFM1level between the rural and the urban Rajshahi cohort. AFM1was found less frequently in the Dhaka pregnant women (31% above LOD, mean 13.9±33.3pg/mL), but in a similar concentration range (1.7-141pg/mL) as in the Rajshahi cohort. Urinary AFM1levels did not show significant associations with the participants food consumption pattern. In conclusion, when compared to biomarker data from other countries, detection frequency and urinary AFM1levels in our Bangladeshi cohorts raise concerns regarding their exposure to potent carcinogenic aflatoxins.
authors.affiliation: Leibniz-Research Centre for Working Environment and Human Factors (IfADo) at the TU Dortmund, Ardeystr. 67, D-44139 Dortmund, Germany; Department of Biochemistry and Molecular Biology, Rajshahi University, Rajshahi-6205, Bangladesh. Electronic address: nur_rubd@yahoo.com.
authors.forename: Nurshad
authors.initials: N
authors.lastname: Ali
authors.affiliation: Leibniz-Research Centre for Working Environment and Human Factors (IfADo) at the TU Dortmund, Ardeystr. 67, D-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: 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, D-44139 Dortmund, Germany. Electronic address: degen@ifado.de.
authors.forename: Gisela H
authors.initials: GH
authors.lastname: Degen
mesh_terms: D000293:Adolescent; D000328:Adult; D016604:Aflatoxin B1; D016607:Aflatoxin M1 / Q000652:urine*; D001459:Bangladesh; D015415:Biomarkers / Q000652:urine; D004032:Diet; D004784:Environmental Monitoring; D004785:Environmental Pollutants; D005260:Female; D005506:Food Contamination; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D012424:Rural Population; D012621:Seasons; D014505:Urban Population; D055815:Young Adult
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; D016607:Aflatoxin M1; D016604:Aflatoxin B1
keywords: Aflatoxins; Biomarkers; Cohorts; Exposure; Urine