Pesticides and the Food Chain

Many pesticides with high lipid solubility tend to accumulate in the tissues of predatory species, including humans. Although most pesticides used today are biodegradable and have lower partition coefficients, not all modern insecticides are unaffected by this problem. Therefore, it is important to understand the principles involved. 

Several terms have been used to describe this phenomenon, namely, biomagnification, bioconcentration, and bioaccumulation. However, the pesticide is not always concentrated or magnified as it moves up to the food chain, so the latter term is preferable (Nakatsugawa and Nelson, 1972). For example, dieldrin residue in cod at 0.009 ppm (whole fish bases) was less than in the sand eel, the major diet of the cod, at 0.016 ppm. Dieldrin residue in a macrozooplankton (crustacea) at 0.16 ppm was higher than in any of the fish examined 

Animal Insecticides Ambient concentration (ppb) Magnification factor 

Source From Nakatsugawa, T. and Nelson, P.A., in Environmental Toxicology and Pesticides, Mat-sumura, F., Boush, G.M., and Misato, T., Eds., Academic Press, New York, 1972, p. 501. With permission. 

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