Surface contamination, uptake routes

Biomagnification along terrestrial food chains is principally due to bioaccumulation from food, the principal source of most pollutants (Walker 1990b). In a few instances, the major route of uptake may be from air, from contact with contaminated surfaces, or from drinking water. The bioaccumulation factor (BAF) of a chemical is given by the following equation ... 

Ichikawa et al. 1990 NIOSH 1986b). MBOCA has been measured in the urine of workers following dermal and/or inhalation exposures, suggesting rapid absorption and excretion. Information on the absorption of MBOCA by humans as a result of ingestion of contaminated water or food has not been found and would be useful in assessing the uptake of MBOCA from contaminated foods. Further information on the uptake of MBOCA by all three exposure routes, particularly the differentiation of dermal and inhalation exposure in workers, would be helpful in determining potential uptake of MBOCA as a result of exposure to contaminated air, water, or foods, or contract with contaminated surfaces. 

One theory on bioaccumulation from sediment states that porewater exposure is the main route of uptake for animals that live under the sediment s surface or closely associated with it (Adams 1987 Adams et al. 1985 Knezovich and Harrison 1988 Oliver 1987 Roesijadi et al. 1978a,b). Other studies, however, conclude that ingestion of contaminated sediment can be a major contributor to body burden of hydrophobic compounds (Boese et al. 1990 Lynch and Johnson 1982 McLeese and Burridge 1987 Meador et al. 1995 Weston 1990). In those cases where uptake via water is important, the presence of sediment can markedly reduce accumulation and toxicity of a chemical (Knezovich and Harrison 1988 Knezovich and Inouye 1993 Schrap and Opperhuizen 1990) because of the ability of the sediment to sorb the chemical and reduce its dissolved concentration. 

---