Abstract
In order to evaluate the state of the environmental pollution in Chiba Prefecture, the correlation between sulphur oxides concentration in ambient air and sulphur content in the leaves of woody plants (Platanus acerifolia Willd., Salix babylonica L., Robinia pseudo-acacia L., Viburnum awabukiK. Koch, Juniperus chinensisL., andNerium indicumMill.) has been investigated. Sampling was made once every two months during the period from May 1984 to March 1986. Sulphur in the leaves of woody plants was analyzed by BaSO4gravimetry and sulphur oxides was measured by PbO2method.
The results obtained from these experiments as follows: 1. The sulphur concentrations were between 0.06 and 0.43mg S03/d/ 100 cm2 Pb02 and the value of the concentration in the industrial area was four times higher than that of the concentration in the agricultural area. 2. The sulphur content in the leaves ofP. acerifoliaWilld., S. babylonicaL., R. pseudo-acaciaL., V. awabukiK. Koch., J. chinensisand N.indicumMill. were 0.84-1.21, 0.98-1.88, 0.96-1.45, O.93-3.93, 1.05-4.96 and 0.92-3.07 mg/g dry weight, respectively.
3. The correlation formula between sulphur oxides concentration and sulphur content in the leaves of the woody plants was Y=1.25 X-46 and its coefficient of correlation (r) was 0.76. Especially, the correlation formula of it in the industrial area was Y=1.28 X-0.42 and its coefficient of correlation (r) was 0.84.
