Assessment of different physicochemical parameters of leachates from two locally unbranded yogurt containers in Erbil City, Kurdistan Region, Iraq

Exposure of humans to toxic chemicals can lead to significant health risks. This study evaluates the physicochemical parameters in the leachates of two local yogurt containers purchased from Erbil City, Iraq, comprising white plastic (WPC) and aluminum containers (ALC). Acetic acid, distilled water, ethanol, lactic acid, sodium carbonate, and sodium chloride at varying concentrations were examined as effective simulants for assessing leaching from the two containers (1.0 cm² container/1.0 mL simulant). Leaching experiments were conducted under three different conditions, including Refrigerated/First Condition (1stC, 4±1℃ for 72 hours), Ambient/Second Condition (2ndC, 25±2℃ for 24 hours), and Elevated/Third Condition (3rdC, 60±2℃ for 2 hours). After leaching, many tests, such as the change in physical state, pH measurement, estimation of leached oxidizable materials, UV absorbing materials (UV-AMs), weight loss (WL), and heavy metals (HMs) level, were examined for the obtained leachates. The observations showed that there was a significant change on the ALC specimens' surface. Most of the analyzed HMs were found in levels below the permissible limits (1000 μg/L), except the content of Pb was found above this limit in the ALC leachates using 5% sodium carbonate. The results showed that the maximum migration level of oxidizable matters and UV-AMs were observed in the leachates of ALC (3rdC, 5% sodium carbonate) and WPC (1stC and 2ndC, lactic acid), respectively. The WL was additionally recorded at a high level in many kinds of local yogurts. Results exceeded many international guidelines and clearly confirm that the continuous use of the ALC and WPC may contribute significantly to the daily intake of toxic chemicals and can pose a significant health hazard.