Human Exposure to Antimony. III. Contents in Some Human Excreted Biofluids (Urine, Milk, Saliva)

Humans are exposed to antimony through a variety of natural and anthropogenic sources. Even though the real value of the approach is still uncertain, it has become common practice to use excreted biofluids (i.e., urine, milk, saliva) to diagnose pollutant exposure due to the noninvasive nature of sampling these fluids. In this third review of the series on human exposure to antimony, the authors present a critical discussion of the available literature, focusing on antimony concentrations in urine, milk, and saliva, while maintaining their three specific objectives: (a) objective evaluation of published data in consideration of the methodology, (b) establishment of a range of reasonable values for antimony concentrations in the biofluids covered in the review, and (c) assessment of the usefulness of the data in assessing environmental and occupational exposure. The authors observed that most data collected are not supported by the analysis of certificate reference materials, a large number of papers have reported concentrations that are close to the detection limit of the analytical techniques used, and recent studies using more sensitive techniques report lower concentration values. When these methodological limitations are taken into account, it becomes difficult to establish a reliable antimony background value for human urine from healthy unexposed individuals; though an upper limit of 0.1 μg L−1 can be suggested. Using antimony content in urine appears justified when examining occupational and environmental exposure to nearby localized sources (e.g., mines, smelters) studies, but its usefulness is less clear for assessing the effect of diffuse pollution. The very limited number of studies on human milk and saliva does not allow any solid conclusions to be drawn.