A team of scientist from Cyprus University of Technology and Harvard School of Public Health assessed a small, non-representative sample of the Cypriote population for their urinary antimony (Sb) levels. Samples were collected as spot samples on two separate occasions, 7-days apart. The 35 study participants also answered a questionnaire about their water consumption habits. In particular, water consumption from different sources (PET-bolted water, tap water, and water from polycarbonate (PC) 19L dispensers) was of interest. Antimony is a metalloid commonly used as catalyst in the production of polyethylene terephthalate (PET) plastic. The researchers also assessed in which form water was consumed (pure water, coffee, tea, juice, and other).
Human Sb levels were measured by taking urine spot samples. Urinary Sb concentrations showed no conclusive association with drinking water sources, i. e. PET-bottled water or others. The authors conclude that the study’s small sample size and non-representative nature are possible reasons why no clear trends were observed. They do however point out that further studies are needed to increase understanding for Sb exposure sources. The range of urinary Sb values in this study was 0.03 – 0.28 µg L-1. The mean urinary Sb concentration in this study was 92.4 ng L-1, which was comparable with a large survey conducted in the general US population (114 ng L-1(1999–2000 NHANES survey)).
It is important to note that urinary Sb concentrations were significantly higher in women, even after adjusting for several factor that may affect levels, such as age, education, bottled water consumption, smoking and body-mass index, calling for additional research to look into possible Sb-related gender effects.
While there are several studies showing increased levels of Sb in PET-bottled waters (especially if storage conditions are at higher temperatures), no clear trend was observed in this present study between consumption of PET-bolted water and increased urinary Sb levels. However, due to the small sample size this absence of an association is no confirmation for the absence of a link, either.
Urinary antimony levels are thought to be a good indicator for overall antimony exposure, regardless of the source. Antimony is used as catalyst in the production of PET plastic and has been shown to migrate from PET into water or food simulants under normal conditions of use. Levels found range between 0.001 and 2.6 µg/L. The current WHO guideline value for Sb is 20 µg/L, the European specific migration limit (SML) for antimony is 40 µg/L. In California, a new public health goal (PHG) currently is being discussed of 0.7 µg/L , with the existing PHG being 6 µg/L. The Japanese drinking water standard is 2 µg/L.
Makris,KC et al. (2013). “Association of drinking-water source and use characteristics with urinary antimony concentrations.” Journal of Exposure Science and Environmental Epidemiology 23, 120–127.