Polychlorinated Biphenyls in Food

Abstract

We measured the concentrations of 205 polychlorinated biphenyl (PCB) congeners in 26 food items: beef steak, butter, canned tuna, catfish, cheese, eggs, french fries, fried chicken, ground beef, ground pork, hamburger, hot dog, ice cream, liver, luncheon meat, margarine, meat-free dinner, milk, pizza, poultry, salmon, sausage, shrimp, sliced ham, tilapia, and vegetable oil. Using Diet History Questionnaire II, we calculated the PCB dietary exposure in mothers and children participating in the AESOP Study in East Chicago, Indiana, and Columbus Junction, Iowa. Salmon had the highest concentration followed by canned tuna, but fish is a minor contributor to exposure. Other animal proteins are more important sources of PCB dietary exposure in this study population. Despite the inclusion of few congeners and food types in previous studies, we found evidence of a decline in PCB concentrations over the last 20 years. We also found strong associations of PCB congener distributions with Aroclors in most foods and found manufacturing byproduct PCBs, including PCB11, in tilapia and catfish. The reduction in PCB levels in food indicates that dietary exposure is comparable to PCB inhalation exposures reported for the same study population.

Figure 1.

Quality control metrics. The performance of our analytical method is assessed by the extraction efficiency for 3 surrogate compounds (%Recovery, left); congener-specific limits of quantification in 10 method blanks (LOQ in pg sample⁻¹, middle); and the reproducibility of triplicate analysis (Reproducibility, right) as the coefficient of variation (%CV) versus concentration (pg g⁻¹ WW).

Figure 2.

PCB concentrations in foods (pg g⁻¹ WW), calculated as the sum of the mean of the congeners measured in triplicate in each food item. The error bars indicate the standard deviation. Salmon was wild caught frozen; catfish and tilapia were farmed frozen; liver was beef and chicken; meat-free dinner was a mixture of frozen macaroni-and-cheese and tortillas; milk was 2%; and luncheon meat was ham and turkey breast.

Figure 3.

Toxic equivalency (TEQ in pg kg⁻¹fat; filled bars and top axis) and neurotoxic equivalent (NEQ in pg g⁻¹ WW; open bars and bottom axis) values in foods. The error bars indicate the standard deviation. Salmon was wild caught frozen; catfish and tilapia were farmed frozen; liver was beef and chicken; meat-free dinner was a mixture of frozen macaroni-and-cheese and tortillas; milk was 2%; and luncheon meat was ham and turkey breast.

Figure 4.

PCB dietary exposures of mothers (gray) and middle and high school children (white) participating in AESOP Study in East Chicago, Indiana (EC; top-left boxplot) and in Columbus Junction, Iowa (CJ; top-middle boxplot) together with their proportions of PCB dietary exposure sources (bottom pies); and PCB inhalation exposures in the same study populations (right lines) in μg year⁻¹. ^aInhalation exposures in AESOP Study populations were calculated as time-integrated products of airborne PCB concentrations and inhalation rates. ^bInhalation exposures through school air in AESOP Study children were calculated as the sum of seasonal exposure during spring, autumn, and winter.