A modified creatinine adjustment method to improve urinary biomonitoring of exposure to arsenic in drinking water

摘要

Spot urinary concentrations of arsenic (As) require adjustment for hydration variation. There is no consensus as to the most appropriate method. We compared the performance of creatinine (Cre), specific gravity (SG), osmolality and a modified variant of Cre adjustment on spot urinary As concentrations of 203 volunteers from the UK. Strength in correlation between drinking water total As and urinary non-arsenobetaine As was used to indicate good performance. Performance of the order: Cre (modified) > SG > osmolality > unadjusted > Cre (routine) was observed. Only Cre (modified) adjustment performed significantly better than unadjusted concentrations and both Cre (modified) and SG performed significantly better than Cre (routine). This is the first study to compare the performance of multiple hydration adjustments of urinary As on the basis of reflectance of external exposure and, importantly, allows others to apply this methodology to existing data without further measurements.