Total and speciated urinary arsenic levels in the Spanish population.

Background: Very few studies exist on urinary arsenic exposure in Spain.

Objective: To evaluate total and speciated urinary arsenic (As) levels in a Spanish population sample.

Methods: Demographic, lifestyle and dietary data was collected for 124 volunteers (aged 20-76years; 88 women and 36 men), who were tested for total arsenic and five arsenic species using high-performance liquid chromatography-inductively coupled plasma mass spectrometry.

Results: Arsenobetaine (AB) and dimethylarsinic acid (DMA) were detected in 96.8% of the study participants (limit of detection (LOD) 1.0μg/L for AB and 1.9μg/L for DMA). Monomethylarsonic acid (MMA) and arsenous acid (As(III)) were detected in 5.6% (LOD 1.8μg/L) and 1.6% (LOD 1.4μg/L) of the participants, respectively; arsenic acid (As(V)) was not detected (LOD 1.4μg/L). AB and DMA (geometric mean (GM) 29.1μg/L and 7.5μg/L, respectively) were the main contributors to total urinary arsenic levels. Urinary DMA was positively associated with AB.

Conclusion: Total arsenic levels observed in the Spanish population sample were higher than those reported by other European studies. The most recurrent urinary arsenic species was AB, followed by DMA, probably attributable to the high Spanish consumption of seafood. We recommend using inorganic As+MMA as the two main urinary biomarkers for inorganic As exposure. Our results provide reference data for analysing arsenic speciation results and assessing human exposure.