Analysis of 200 food items for benzo[a]pyrene and estimation of its intakein an epidemiologic study

Animal studies have shown that dietary intake of benzo[a]pyrene (BaP), a po lycyclic aromatic hydrocarbon (PAH), causes increased levels of tumors at s everal sites, particularly in the upper gastrointestinal tract. However, th e role of dietary intake of BaP and cancer in humans is not clear. We creat ed a BaP database of selected food products that could be linked to Food Fr equency Questionnaires (FFQs) to estimate BaP intake. BaP levels were measu red for each food line-item (composite samples) which consisted of a variet y of foods in a FFQ. Composite sample parts were derived from the Second Na tional Health and Nutrition Examination Survey (NHANES II) which represents the most common food items consumed by the general population. Meat sample s were cooked by different techniques in controlled conditions, and by vari ous restaurants and fast-food chains. Non-meat products were purchased from the major national supermarket chains. The quantities of BaP were measured using a thin-layer chromatography (TLC)/spectrofluorometer technique and w ere highly correlated with both BaP (radius = 0.99) and sum of carcinogenic PAH (r = 0.98) measured by HPLC technique. We linked our database to the r esults from a FFQ and estimated the daily BaP intake of various food items in 228 subjects in the Washington, DC metropolitan area. The highest levels of BaP (up to about 4 ng BaP/g of cooked meat) were found in grilled/barbe cued very well done steaks and hamburgers and in grilled/barbecued well don e chicken with skin. BaP concentrations were lower in meats that were grill ed/barbecued to medium done and in all broiled or pan-fried meat samples re gardless of doneness level. The BaP levels in non-meat items were generally low. However, certain cereals and greens (e.g. kale, collard greens) had l evels up to 0.5 ng/g. In our population, the bread/cereal/grain, and grille d/barbecued meat, respectively, contributed 29 and 21 percent to the mean d aily intake of BaP: This database may be helpful in initial attempts to ass ess dietary BaP exposures in studies of cancer etiology, Published by Elsev ier Science Ltd.