Toxicological evaluation of commercial mineral water bottled in polyethylene terephthalate: a cytogenetic approach with Allium cepa

The aim of this study was to ascertain the possible toxicological effects o f chemicals released into mineral water packaged in polyethylene terephthal ate (PET) bottles. Two commercial mineral waters, bottled both in PET and g lass and stored under different conditions, were examined using the Allium cepa test. The influence of the water samples on macroscopic (root length, colour and form) and microscopic (root tip mitotic index, chromosome aberra tions) parameters was examined. The water samples were analysed after: (A) controlled-condition storage (no direct light exposure and 18 +/- 2 degrees C), (B) storage at 40 degreesC for 10 days, in the dark (migration test in accordance with 82/711/EEC), and (C) exposure to sunlight and varying tempe ratures (18-38 degreesC, mean temperature 25 +/- 3 degreesC). The two water samples bottled in PET induced cytogenetic aberrations regardless of the s torage conditions. These signs of toxicity were evident even only 8 weeks a fter bottling, which is well within the recommended expiry date. Storage co nditions were very important, as is suggested by the finding that chromosom al aberrations were particularly apparent after exposure to direct sunlight . However, as plant systems are not considered as primary screening tools b y current international guidelines for mammalian systems, extrapolation of the results from this test system to other systems and, eventually, to huma n beings should be based on results from a battery of assays covering vario us metabolic pathways.