Field and laboratory methods to monitor lake aerosols for cyanobacteria and microcystins

摘要

This study tested field and laboratory methods for the collection of cyanobacteria and microcystins emitted from lake water. These methods feature a highly portable, on-lake system for collecting aerosols directly from the lake, as well as a laboratory system for measurement of aerosols from freshly collected water samples under controlled conditions. Membrane air filters (0.45 mu m) collected small particles such as picoplankton (0.2-2.0 mu m) from aerosolized lake water. Picocyanobacteria were distinguished from other photosynthetic cells with epifluorescence microscopy using excitation filters for chlorophyll a (435 nm) and for phycobilin pigments (572 nm), characteristic of cyanobacteria. Aerosolization of picocyanobacteria ranged from 8872 to 167,297 cells m (-3) in the field and 23,764 to 365,011 cells m (-3) in the laboratory. Microcystin levels from field air filters ranged (below detectable limits) < 13-384 pg MC m (-3) of air. The described methods could be used for monitoring aerosolized cyanobacteria for public health purposes.