Ivan J. Stotz

Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School



Since the 1960's people have become concerned about pesticide residues and their effects on the environment including the human population. Polychlorinated biphenyls (PCB's), one general class of residues, have been commercially manufactured in the United States since 1929. They have been used in many products such as plasticizers, hydraulic fluids, lubricants, electrical capacitors, electrical transformers, vacuum pumps, heat transfer systems, wax extenders, dedusting agents, surface coatings, adhesives, printing inks, pesticide extenders and carbonless reproducing paper. Food and Drug Administration guidelines require that the maximum amount of PCB's should not exceed 0.20 parts per million (ppm) in milk (equivalent to 5.0 ppm in milk fat), however, PCB levels have been found as high as 27.8 ppm. Foods have been contaminated from the containers in which they are shipped or stored. Of 637 samples of human tissues studied in 18 states and the District of Columbia, 198 (31.1%) contained measurable amounts of PCB's and 125 (19. 6%) contained trace amounts. Samples of adipose tissue of occupationally exposed humans in Michigan have been found to contain as much as 180 ppm (fat basis). The long-range effects of PCB's on humans and other organisms is not known. The objective of this study was to determine the effects of known concentrations of PCB's on white pelican hepatocytes and to obtain quantitative information regarding the severity of these effects by electron microscopic analysis.

Library of Congress Subject Headings


Liver -- Diseases




Number of Pages



South Dakota State University