بررسی اثر نور خورشید، مدت زمان نگهداری و دمای محیط بر آزاد سازی فلزات سنگین از ظروف پلی اتیلن به آب های بطری شده

Background and purpose: Bottled water is widely packaged and distributed in PolyethyleneTerphthalate (PET) bottles with plastic caps. Plastic materials in bottles, and other additives such as heavy metals, can leak into water during manufacturing or storage process in different ambient conditions. The main objective of this study was to investigate the effect of sunlight and environmental temperature on the release of heavy metals from PET bottles into water. Materials and methods: The study was conducted in six brands of bottled water (0.5 L) in five provinces of Iran, 2015. The levels of Pb, Ni, Cd and Sb were determined in bottled waters in different conditions including room-temperature of 27±2°C, sun exposure to 45±3°C, and with/without foil coating. Different temperatures (45°C, 60°C and 75°C) were also used in specified time ranges from 5 to 50 days. Measurement was done by ICP- AES and data was analyzed in Minitab. Results: Concentrations of Pb, Ni and Cd in bottled water did not show any significant changes in direct sunlight exposure and ambient temperature but Sb concentration was found to be higher in all samples when storage duration increased. In some samples, it even exceeded the maximum allowed value (5 ppb). Conclusion: Direct radiation exposure to sunlight, increasing the ambient temperature and storage duration, lead to increase in concentration of antimony in bottled water.