Assessment of polychlorinated biphenyls (PCBs) in cheese from Rio Grande do Sul, Brazil

Polychlorinated biphenyls (PCBs) are among the most toxic environmental pollutants. Food, especially animal based, has been described as the major source for human exposure to PCBs. We investigated PCB levels (congeners 10, 28, 52, 153, 138, and 180) in cheese from 14 cities of Rio Grande do Sul, Brazil. The fat was extracted using sodium sulfate and petroleum ether, and PCBs purification was conducted using florisil and hexane. The identification and quantification were made in a gas chromatograph with microelectron capture detector (GC-μECD). PCB congeners were found (lower bound data as ng g−1 fat) in the following rank: 52 (15.75) > 180 (4.91) > 28 (3.43) > 153 (3.00) > 10 (2.38) > 138 (1.37). ∑PCB contamination ranged from 0 to 78.32 ng g−1 fat. Differences in PCB levels between industrialized (33.32 ng g−1 fat) and homemade (26.58 ng g−1 fat) cheese and between two different regions (36.19 vs. 26.95 ng g−1 fat) were not statistically significant. For university students, the estimated daily intake (EDI) of PCBs from cheese ranged from 0 to 3.13 pg kg−1 b.w. EDI was significantly higher for industrialized than homemade cheese, and for cheese from Mountain/Porto Alegre region than from Santa Maria/South/Western region. No sample exceeded maximum level of PCBs allowed in dairy products in the European Community.