Risk assessment and pollution status of migration heavy metals from polyethylene terephthalate bottled water under sunlight

Public health concerns regarding the migration of heavy metals from polyethylene terephthalate bottles into drinking water have prompted this study. We investigated the leaching behavior of four metals lead, nickel, chromium, and cobalt under prolonged sunlight exposure. A total of 44 samples were collected from five different commercial bottled water brands in Sulaimani, Iraq, and analyzed using inductively coupled plasma optical emission spectrometry. The results revealed a statistically significant increase in the concentration of most metals after sunlight exposure; however, all levels remained below international permissible limits. Health risk assessment showed non-carcinogenic hazard index values ranging from 1.2E-02 -2.67E-01 before and 3.2E-02 to 3.53E-01 after sunlight exposure. Lifetime incremental carcinogenic risk ranged from 2.38 E-07-1.9 E-05 before and 1.95 E-07 to 5.50 E-05 after sunlight exposure, all within safe limits. The heavy metal pollution index was below the hazardous threshold of 100 for most samples, except one post-exposure, which was classified as poor quality. These findings indicate that, although bottled water generally complies with safety standards, prolonged sunlight exposure can enhance the leaching of hazardous metals, potentially increasing contamination. Therefore, minimizing sunlight exposure during storage and distribution is strongly recommended to protect consumer health.