A relatively simple eye-safe compact GaAlAs lidar with solid state elements for the indoor/outdoor detection of aerosol/dust pollution layers and measuring its range and height has been developed and tested. An important feature of this full trouble-free instrument is the low eye-safe energy level compatible with ANSI standard, low mass, and low voltage circuits with only digital exchange technique, simplicity, and reliablilty. In active operation mode the lidar produces the backscatter coefficient profiles within a hundred meters and estimates of atmosphere turbidity over the road. In a passive mode it can measure a solar radiation flux. An application of this lidar's data for the model tuning in situ is to predict heavy toxic aerosol plume spreading from low sources over the city building or the territory with complex terrain is illustrated.