Worrying levels of antimony found in popular fruit juices
A potentially lethal toxin at concentrations up to 17 times higher than found in previous studies has been detected in popular fruit juices, according to research published by the Royal Society of Chemistry.
Looking at 42 juice drinks from 16 different brands, the scientists found antimony concentrations above EU limits for drinking water in eight products. No previous reports of beverages exceeding this limit exist.
Antimony and many of its compounds are toxic. Clinically, antimony poisoning is very similar to arsenic poisoning. In small does, antimony causes headaches, dizziness and depression but in large doses causes violent and frequent vomiting and will lead to death in a few days. The discovery, highlighted in the Journal of Environmental Monitoring, has led scientists to call for extensive research.
Concentrations up to a factor of 2.7 above the EU limit for drinking water were found in 42 drinks, including blackcurrant, mixed fruit and strawberry, across 16 brands obtained from local grocers in Greece, Denmark and Scotland. All were produced in the UK. One particular brand of blackcurrant juice widely available to consumers showed "particularly high" antimony concentrations. The overall increase may be due to antimony either being leached from the packaging material or introduced during manufacturing.
For this report, the level of antimony concentration was measured in 42 containers of red fruit juices including blackcurrant, strawberry, raspberry, sour cherry, mint and synthetic caramel using inductively-coupled plasma mass spectrometry (ICP-MS). The results showed antimony in juices with up to 17-fold higher concentrations compared to previous reports on mineral waters in PET-bottles.
Antimony has no known biological function and the effects of long term human exposure are unknown. Antimony trioxide, a suspected carcinogen and listed as a priority pollutant by the US Environmental Protection Agency, is used as a catalyst in the production of polyethylene terephthalate (PET), which is used to package foodstuffs.
Previous studies concerning antimony leaching into bottled water have investigated the effects of variable physical conditions such as time, temperature and sunlight. But Claus Hansen and colleagues at the University of Copenhagen, Denmark, speculated that as citric acid is known to be an efficient antimony extractant acidic fruit drinks could leach more antimony than water from PET bottles.
The highest antimony concentrations, found in one particular brand of blackcurrant juice, were above the recommended EU levels for drinking water (5 micrograms per litre). Even though the levels of antimony were high in the juices, the team was unable to identify the source of the contamination, which could arise from the packaging material quality, the drinks production process or from sugar-aided extraction.
"The antimony concentrations in the products tested exceed the antimony limit in EU drinking water but no antimony limits exist for foodstuffs so no legislation has been broken", says Hansen. "However, we cannot be sure that the antimony levels found are harmless. The human exposure to antimony is increasing and since antimony has no known biological function, there is concern about its long term effects."
Agneta Oskarsson, an expert in food toxicology at the Swedish University of Agricultural Sciences, Uppsala, said: "This work emphasises the need to follow up exposure and health risks due to increased usage of such elements as knowledge on antimony exposure and toxicity is scarce, therefore more data on the antimony speciation is required."
The researchers concluded: "We have measured antimony in juices with up to 17-fold higher concentrations compared to previous reports on beverages in PET-bottles. Trends in the data material indicate that the antimony has leached from the packing material; however, it cannot be excluded that the antimony was present prior to packing. Thus, further studies are warranted."
The research team is now attempting to detect the source of the contamination and to test whether sugar acts as an extracting agent for antimony in PET materials, which could lead to restrictions in the use of PET for packaging sugar-rich foodstuffs.
Elevated antimony concentrations in commercial juices Claus Hansen, Alexandra Tsirigotaki, et al, Journal of Environmental Monitoring., 2010 DOI: 10.1039/b926551a