Vanadium Concentrationsin Atmosphere Akiyoshi Sugimae’ and Toshio H a s e g a w a
Environmental Pollution Control Center, Osaka Prefecture, 1 -chome, Nakamichi, Higashinari-ku, Osaka, Japan
~~
~
Measurements of concentrations and particle size distributions of atmospheric vanadium are carried out in Osaka. The average vanadium concentrations a t 11 sampling sites range from 0.05-0.55 pg/m3 with the overall average of 0.16 pg/m3, and are related to quantities of fuel oil burned in the 2 km x 2 k m areas around the sampling sites. There is a close correlation between vanadium concentrations and sulfur dioxide concentrations with the exception of rainy days; the correlation coefficients range from 0.79-0.91. Slopes of regression lines relating vanadiu m concentrations t o sulfur dioxide concentrations in the atmosphere range from 2.9-7.7 (pg/m3 - p p m ) ; these are similar to the values expected from the vanadium and sulfur content in fuel oils. Mass median equivalent diameters of atmospheric vanadium range from 0.23-0.76 pm in diameter with the average of 0.46 pm in diameter. Current interest in urban airborne particulates as air pollutants has led to many studies of their elemental compositions. However, relatively little work has been reported in the literature relating to the evaluation of vanadium concentration in airborne particulates. Kneip e t al. (1970) reported a very significant inverse correlation of vanadium concentration to temperature. They suggested that the main source of atmospheric vanadium was combusion of vanadium-containing fuel oils and that vanadium served as a tracer for particulates from oilburning sources. Morrow and Brief (1971) reported t h a t atmospheric vanadium concentrations in winter in metropolitan New York were higher t h a n those in the summer. From this result, they concluded t h a t fuel oil combustion effluents released from apartment houses and office buildings near rooftops were the important sources of localized vanadium concentrations in addition to high stack emission characteristic of power plants. The present study aimed at elucidating further the emission sources of atmospheric vanadium and also a t obtaining particle size distribution of atmospheric vanadium particulates, of which no previous work has been reported.
stage 2, 12 to 3.5 pm in diameter; stage 3, 3.5 to 1.2 pm in diameter; and stage 4, less than 1.2 pm in diameter. The particulates a t stages 1 to 3 are collected on glass fiber filters 21 m m in diameter, and a t stage 4 are collected on glass fiber filter 55 m m in diameter. The sampler was operated a t a flow rate of 30 l/min for 24 or 96 hr. Samplings of airborne particulates were carried out by high-volume air samplers every day except Saturday in J u n e and October, 1969, a t the Suita City Office and the Sakai City Institute of Hygiene, and every Tuesday from J u n e 1970 till March 1971 a t 11 sampling sites shown in Figure 1. The land of Osaka Pref. is parceled into 2-km x 2-km lots. The quantities of fuel oils burned annually in the lots are also illustrated in the figure. These data were presented by the Air Pollution Control Department of Osaka Prefecture. Figure 1 permits prediction as to the extent of air pollution by fuel oil combustion a t each sampling site to be made with some degree of confidence. Samplings by the cascade centripeter were carried out a t the Environmental Pollution Control Center from October 1969 until February 1970. Analysis. Before and after collection of airborne particulates, a glass fiber filter was equilibrated a t 25°C and 50% relative humidity for 24 hr, then weighed. Airborne particulate concentration was calculated by dividing the total weight of the particulates by the volume of air sampled. Vanadium in airborne particulates collected on the
ANNUAL CONSUMPTION QUANTITY OF FUEL OILS
