Variables: concentration Keywords: stream pyrethroids Substances: Chlorpyrifos (SBPBAQFWLVIOKP-UHFFFAOYSA-N) Prallethrin (SMKRKQBMYOFFMU-UHFFFAOYSA-N) Chlorpyrifos-methyl (HRBKVYFZANMGRE-UHFFFAOYSA-N) Cypermethrin (KAATUXNTWXVJKI-UHFFFAOYSA-N)