The sorption of selected polychlorinated biphenyl (PCB) congeners (from tri to deca chlorinated) by three food-packaging plastic films [polyethylene, polyvinyl chloride (PVC), and polystyrene] from an aqueous solution was investigated. From the data generated, PCB uptake, partition, and diffusion coefficients were calculated for the various films. Polyethylene exhibited the highest PCB uptake, diffusion, and partition coefficients when compared to the other materials. Although PVC indicated larger sorption diffusion and partition coefficients for the lower chlorinated congeners than polystyrene, a reversal of this trend was observed for the higher congeners. For polyethylene and PVC, the PCB uptake decreased as the chlorine numbers in the congeners increased, confirming the correlation between increasing chlorination and increasing cohesive density within the PCB molecules. For polystyrene, the uptake decreased from tri to penta congeners, but showed an increase for the hexa, and then a decreased uptake until the deca chlorination. A comparison of the molecular sizes of the PCB congeners showed that the partition (Ke) and sorption diffusion (Ds) coefficients generally decreased with their increasing molar volumes. The resulting Ke values were used to determine the extent of sorption because these values indicate the affinity of PCBs for the plastic films. Results from this study can be of practical importance for cases of product quality related to the transfer of contaminants from the product to the packaging materials.

Breakfast consumption patterns of the U.S. adult population were examined by using the U.S.D.A. Nationwide Food Consumption Survey. Results indicated that approximately one-quarter of the adult population skipped breakfast regularly. For those adults who consumed breakfast, the four most commonly consumed breakfasts were eggs, bread, and coffee; ready-to-eat cereal with milk; coffee and bread; and eggs, bread, and milk. The sample was partitioned by six age/sex classes and by four breakfast consumption patterns. Assessments of average intakes of seven frequently underconsumed nutrients showed that omission of the breakfast meal had a significant negative impact, particularly among adult females, on the diet quality. Findings indicated that for all age/sex classes, consumption of ready-to-eat cereal at breakfast, whether frequently or on a more limited basis, increased the average daily intake levels of the underconsumed nutrients. Further, groups of adults who regularly consumed ready-to-eat cereal at breakfast had, on average, lower average daily intakes of fat and cholesterol. It was concluded that regular breakfast consumption greatly enhanced the overall diet quality of the U.S. adult population.

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From 7-day food diaries of a cross-sectional sample of American children (n = 657), breakfast consumption patterns were assessed and related to average daily nutrient intake patterns. Results indicated that few of the children skipped breakfast and that breakfast consumption made a significant contribution to the average child's daily nutrient intake. Further, children who had ready-to-eat cereals at breakfast three or more times during the 1-wk period were found to have consumed significantly less (p less than 0.001) fat and cholesterol and significantly more (p less than 0.001) fiber, thiamin, niacin, riboflavin, iron, folacin, pyridoxine, and vitamins B12, A and D than those who had no ready-to-eat cereal at breakfast. Average total daily intakes of the same groups had fewer significant differences. Comparison of the average nutrient composition of the three types of consumed breakfasts revealed that the average breakfast containing presweetened or nonsweetened ready-to-eat cereal had a higher content of sixteen nutrients and a lower content of five nutrients than did the average breakfast including no ready-to-eat cereal.

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Six symmetrical tetrachlorobiphenyls have been synthesized. Cyclohexane and methanol solutions of I-VI were irradiated at 300 nm and the products of the reaction identified. In both solvents dechlorination is the major reaction. Intersystem crossing quantum yields and quantum yields of reaction for I-VI have been determined in solution. The excited state responsible for photoreaction was found to be the triplet, and its lifetime was measured in cyclohexane and methanol. The rate constants for triplet decay and reaction were obtained using these data. The position of chloro substitution was found to have a marked effect on the photochemical properties of polychlorobiphenyls; an increase in ortho substituents decreased the lifetime and increased the reactivity of the excited state.