Rainwater quality during 1991–1993 and constituents of milky rain (November 1992) in Bulawayo, Zimbabwe

The status of the atmospheric environment was assessed by characterization of composite precipitation samples collected during 1991–1992 and single event samples in 1992–1993 rainy seasons in Bulawayo, Zimbabwe. The rainwater quality was assessed by analysing various physical and chemical parameters. A typical single event precipitation sample from 10th January 1993 had pH 6.87 and conductance 4.6 μS/cm. The concentrations of anions and cations (μM/l) were sulfate (2.83), chloride (3.79), nitrate (1.16), bicarbonate (13.14), ammonium (0.57), potassium (0.91), sodium (3.78), calcium (8.67), magnesium (1.26), H+ (0.38), copper (0.018) and zinc (0.056). The charge ratio was 0.94, while the conductance ratio was 0.85. The chemical composition of the ‘milky rain’ occurring on 16 November 1992 in the Bulawayo area was analysed and the meteorological conditions that possibly led to the milky rain are discussed. The overall quality of the atmospheric environment in Bulawayo, Zimbabwe is described.