Pesticides in rain.

40 rainwater samples were collected in Hannover and near Peine (Lower Saxony, Germany) in 1992 using a wet-only collector. The samples were extracted by solid phase extraction and analyzed by GC/MS for 59 pesticides. 11 pesticides were found in more than 10 samples. The highest concentrations were observed for terbuthylazine (0.003-0.52 microgram/L), metolachlor (0.003-0.51 microgram/L, mean: 0.10 microgram/L), metalaxyl (0.006-0.48 microgram/L, mean: 0.10 microgram/L) and chlorothalonil (0.003-1.1 micrograms/L, mean: 0.16 microgram/L). The concentrations show a seasonal dependence reflecting the application periods.