浮遊粉じん中の金属成分(第1報) : 鉛による環境汚染

抄録

Concentration of lead in the atmosphere was measured at 12 sampling sites in Osaka every day in June (1969), October (1969) and February (1970). Lead in samples collected by High Volume Air Sampler, Cascade Centripeter, and Tape Air Sampler was determined by emission spectrographic an alysis. The monthly average concentration at various locations ranged from 0.11 to 4.44 μg/m³, with an overall average of 2.03 μg/m³. Distribution of lead content in air borne particulates formed distribution of approximately logarithmic normal type. Its mean value was 0.63% and the upper limit was 1.9% at the one-side significant level of 5%. Size distribution of lead particulates in the atmosphere was also investigated, and it was found that the distribution curves at every sampling site were almost similar and 81-98% of lead particulates were less than 1 μ in diameter. The inverse correlation was found between lead concentration in the atmosphere and wind velocity. The slope of the regression line, representing the ratio of lead concentration to wind velocity was greater in heavy traffic area than in residential area. Diurnal variation of lead concentration, determined continuously every hour by the Tape Air Sampler was also inversely correlated with wind velocity. In addition, correlation between lead and carbon monoxide concentration in the atmosphere was also studied.