Stability of nitrosamines in samples of lake water, soil, and sewage.

N-nitrosodimethylamine, N-nitrosodiethylamine, and N-nitrosodi-n-propylamine were resistant to degradation in soil, sewage, and lake water. No degradation of these nitrosamines was observed in lake water during a 3.5-month period. A lag of nearly 30 days occurred before their slow disappearance from soil; they disappeared slowly from sewage, but a minimum of 50% remained after 14 days. The results with sewage and soil suggesta a microbial involvement in the slow decomposition of these nitrosamines.