The Total Human Environmental Exposure Study (THEES) to Benzo(a)pyrene: Comparison of the Inhalation and Food Pathways

Abstract

The assessment of human exposure to an environmental contaminant requires the measurement of levels present in each pathway of possible contact. In this paper, the design considerations and Phase I results of a human exposure study focused on Benzo(a)pyrene (BaP) are discussed. This study site, located in Phillipsburg, New Jersey, is a city that contains a metal pipe foundry, which is a suspected major source of BaP. Three outdoor PM-10 samplers (used to collect BaP-containing particles with an aerodynamic size of less than or equal to 10 micron) were located in residential areas surrounding the foundry. Ten homes were sampled indoors for PM-10. Some homes have indoor combustion sources, e.g., cigarette smoke or a coal burning stove. The indoor and outdoor samples were 24 hr in duration. The mean outdoor concentration of BaP was 0.9 ng/m3, and the indoor concentrations ranged from 0.1-8.1 ng/m3. Food samples were acquired from family meals each day. They represented a one-third portion of each meal eaten at home. The range of BaP per gram of wet weight of food was between 0.004 and 1.2 ng/g. Of the 20 wk of exposure (10 x 2 wk), 10 had higher food exposures and the other 10 had higher inhalation exposures. Of the two groups, the higher food exposures usually had a greater number of ng of BaP/wk. The dominance of one or the other pathway appeared to depend upon personal eating habits and indoor combustion source use. In some instances, outdoor air pollution led to a major portion of indoor air BaP exposures. Water appears to be a minor source of BaP exposures in the study area.

Cancer Risk Assessment, Indicators, and Guidelines for Polycyclic Aromatic Hydrocarbons in the Ambient Air

“…Several studies have indeed shown that the intake of PAHs via the diet is large (Beckman Sundh et al 1998;de Vos et al 1990) and much higher than the intake via inhalation (Lioy et al 1988;Lodovici et al 1995;Vaessen et al 1988;WHO/IPCS 1998). Data on the origin of PAHs in food are limited; however, it has been suggested that the major part originates from precipitated particulate material (de Vos et al 1990;Lodovici et al 1995).…”

Polycyclic Aromatic Hydrocarbon Metabolites in Urine as Biomarkers of Exposure and Effect

“…Humans may be exposed to these compounds from a wide variety of sources, including occupation (coke oven or iron foundry workers), environment (air pollutants, drinking water), personal habits (e.g., smoking), medical treatment (coal tar), and diet (broiled and smoked foods) (1)(2)(3)(4)(5)(6)(7)(8). PAHs are readily absorbed into the body through the skin, lungs, and gastrointestinal tract.…”

Contribution of locally grown foods in cumulative exposure assessments

“…Only 2.5% of intake is attributable to inhalation, and even less to drinking water consumption, non-dietary ingestion, and dermal contact with contaminated soil (EPA, 2001a). Measured concentrations in foods also reveal that dietary intake can be significantly greater than inhalation for PAHs (Lioy et al, 1988;Butler et al, 1993;Chuang et al, 1999;Wilson et al, 2001). …”