Studies of the influence on the material circulations of street of air pollution.(I)
On the dust-proof effects of the street leaves
1971 Volume 35 Issue 1 Pages 15-21
Details
1971 Volume 35 Issue 1 Pages 15-21
In the previous paper, the authors reported the differeences of the polluted materials in the street trees leaves between heavy and light traffic part. It was clearfyed that they were deposited on the leaves by various manner and, in heavy traffic, lower and side road parts of the tree crown, weredeposited more densely. This investigation was perfromed to clearly the dustproof effects of that tree leaves. The results obtained are as
follows:
1. The total polluted materials in the gauge, which was situated at 1 m height on the street tree zone, were maximum in Apri-May, and minimum in November-March. The authors presumed this was resulted of the abnormal leaffall phen-omenon of the camphor tree in Aipril.
2. Ash part of the polluted materials was the same result as total materials. Thr part, however, was changed seasonaly through the different manner from ash.
This was maximum in winter season.
This was presumed as a result of not only motor car gas but also the soot of heating fuel oil in winter season.
3. Lead contents, which were contained in motor car gas, were increased by followin7; order; winter>autumn>summer>spring.
4. The total polluted materials of a camphor tree leaves was estimated from the total leaf area of a tree, presumed about 1241.3×102 cm2.
In last summer (9/4 in september), there were 40 folds materials of early summer (5/22 inMay). This was presumed as a result of the differences of Ieaf growth form between early and last summer season.
5. A camphor tree was captured the materials more effectively in last summer than in early. It was the noticeble results that the polluted tar materials were highly captrued in last summer: 62% of the total materials at 1 m height on the tree zone.
