Survey of lead, cadmium, iron, copper and zinc in Kasar cheese

Abstract

Lead, cadmium, iron, copper and zinc contents of Kaşar cheese sold in the markets of Ankara, Turkey, were determined over 12 months. A total of 240 samples comprising 10 different brands were analysed. Graphite-furnace atomic absorption was employed for the determination of lead and cadmium, and flame atomic absorption for iron, copper and zinc. The mean (range) of the lead, cadmium, iron, copper and zinc content of the samples were 86 (10–421) μg kg-1, 1.8 (0.3–8.3) μg kg-1, 4.2 (1.0–14.1) mg kg-1, 0.7 (0.3–1.6) mg kg-1 and 37.7 (26.5–63.0) mg kg-1, respectively. The samples in November, December and January contained higher amounts of lead than those in other months (p < 0.01). Moreover, important differences existed in lead content of the samples between different cheese producers (p < 0.01). The differences in cadmium and iron content of the samples for different months were important (p < 0.01). The iron content of the samples among manufacturers also varied significantly (p < 0.01). However, there were no significant differences in copper and zinc contents of the samples over 12 months (p > 0.05). These findings suggested that some contamination occurred during milk production and/or manufacturing of cheese depending on the equipment used. For a consumption of 100 g Kaşar cheese, one would ingest approximately 8.6 μg (4% of the provisional tolerable daily intake, PTDI) of lead, 0.2 μg (0.3%) of cadmium, 0.4 mg (0.9%) of iron, 0.07 mg (2%) of copper and 3.8 mg (6%) of zinc. Therefore, it was concluded that Kaşar cheese is not a significant contributor to the intake of investigated heavy metals.