Urinary arsenic concentration adjustment factors and malnutrition.
This study aims at evaluating the suitability of adjusting urinary concentrations of arsenic, or any other urinary biomarker, for variations in urine dilution by creatinine and specific gravity in a malnourished population. We measured the concentrations of metabolites of inorganic arsenic, creatinine and specific gravity in spot urine samples collected from 1466 individuals, 5-88 years of age, in Matlab, rural Bangladesh, where arsenic-contaminated drinking water and malnutrition are prevalent (about 30% of the adults had body mass index (BMI) below 18.5 kg/m(2)). The urinary concentrations of creatinine were low; on average 0.55 g/L in the adolescents and adults and about 0.35 g/L in the 5-12 years old children. Therefore, adjustment by creatinine gave much higher numerical values for the urinary arsenic concentrations than did the corresponding data expressed as microg/L, adjusted by specific gravity. As evaluated by multiple regression analyses, urinary creatinine, adjusted by specific gravity, was more affected by body size, age, gender and season than was specific gravity. Furthermore, urinary creatinine was found to be significantly associated with urinary arsenic, which further disqualifies the creatinine adjustment.
Nermell
Barbro
B
Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Lindberg
Anna-Lena
AL
Rahman
Mahfuzar
M
Berglund
Marika
M
Persson
Lars Ake
LA
El Arifeen
Shams
S
Vahter
Marie
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001151:Arsenic / Q000652:urine*; D001459:Bangladesh / Q000453:epidemiology; D015415:Biomarkers / Q000652:urine; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000652:urine; D004784:Environmental Monitoring / Q000379:methods; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D008297:Male; D044342:Malnutrition; D008875:Middle Aged; D011237:Predictive Value of Tests; D012959:Socioeconomic Factors; D013046:Specific Gravity; D016482:Urinalysis / Q000592:standards*; D014874:Water Pollutants, Chemical / Q000652:urine*; D014881:Water Supply
D015415:Biomarkers; D014874:Water Pollutants, Chemical; D003404:Creatinine; D001151:Arsenic