Effect of polychlorinated biphenyl compounds on growth of Great Lakes phytoplankton

Abstract

Polychlorinated biphenyls (PCBs) have been used for a variety of industrial applications since 1929 and their presence is now widespread in aquatic and terrestrial ecosystems. In this study, three species of Great Lakes phytoplankton and one common soil alga exhibited growth inhibition when exposed to concentrations of PCB as low as 1 μg/litre while 50 μg/litre was toxic to all cultures. Photosynthesis, measured by Na214CO3 uptake was also depressed by PCB additions, but 14C uptake per cell was stimulated at times. Of the four PCB compounds tested, Aroclor 1016 appeared least toxic and Aroclor 1242 was the most toxic, while Aroclors 1221 and 1248 gave intermediate responses.Examination of cells by electron microscopy showed distortion of chloroplast lamellae and increased cytoplasmic vacuole formation in algal cultures treated with 50 μg/litre PCB. Gross cell morphology changes were also observed under the light microscope.Water quality criteria recommend that persistent organic chemicals which are toxic in concentrations of 5 μg/litre or less should not exceed environmental levels of more than 1/100th of this amount. Levels of PCBs in water from several areas of Lakes Erie and Ontario currently exceed these concentrations.