蘚苔類による大気環境評価法の検討 : 二連式チャンバーを用いた実験装置の開発と性能の検討

抄録

The bryometer using twin chambers is useful for evaluating the air quality. We developed the apparatus characterized as follows. (1) The surrounding air is drawn into each chamber by an air pump. The materi also are then exposed to the air coming through the filter system. (2) A teflon filter for removing air dust and which hardly adsorbs nor decomposes gaseous air pollutants is set at the inlet of each chamber. (3) Sponge filters covered with activated charcoal powder are used for removing air pollutants in the filtered air chamber. (4) The air in each chamber is stirred by a fan. Thus, the samples can be exposed to air pollutants efficiently. (5) 10% Knop's solution drops into each chamber continuously through the sterilizing filter for cultivation. (6) To use the apparatus outdoors, a regulating device was manufactured for operating fan motors and air pumps continuously. The rotation rate of fan is regulated from 1250 to 2500 rpm. The air flow rate is regulated from 0.6 to 1.2 lmin^<-1>. We examind the quality of the apparatus (bryometer) made on an experimental basis. The air velocity around the sample in each chamber was 30〜50cm sec^<-1> when the fan rotated at 1250 rpm. The removal rates of air pollutants in the filtered air chamber were 100% for SO_2 and O_3, and 85 % for NO_2, whereas the removal rates in the non-filtered air chamber were 50% for SO_2, 30% for O_3 and 0% for NO_2. There were no distinctive differences in the air temperature and humidity between the filtered and non-filtered air chambers. The shoots of a species of moss (Plagiomnium maximoviczii (Lindb.) Kop.) were put into a set of twin chambers which was exposed to the mixed gases of 0.1 ppm SO_2, 0.1 ppm NO_2 and 0.1 ppm O_3 for 4 weeks under controlled environments. As compared with the shoots in the filtered air chamber, elongation and growth of fresh and dry weight of the shoots in the non-filtered one were reduced significantly. Furthermore, branching activity of this moss cultured in the non-filtered air chamber was completely suppressed, although 1 or 2 branches appeared on a shoot in the filtered one.