A Comparison Study of Measured Values for Ambient Suspended Particulate Matter Using β Attenuation Method and Gravimetric High-Volume Method —from Intermittent Monitoring Data at Two Sites in Tokyo for a Decade—

Ikuo WATANABE; Osamu ENDO; Sumio GOTO; Kiyoshi TANABE; Tsuguo MIZOGUCHI; Hidetsuru MATSUSHITA

doi:10.5985/jec.10.557

β線吸収法とハイボリュームエアサンプラー法による都市大気中の浮遊粉塵の測定値の比較

―東京の2監視局での10年間にわたる間欠測定調査より―

渡辺征夫, 遠藤治, 後藤純雄, 田辺潔, 溝口次夫, 松下秀鶴

著者情報

ジャーナルフリー

2000 年 10 巻 3 号 p. 557-572

DOI https://doi.org/10.5985/jec.10.557

詳細

発行日: 2000/09/29 受付日: 2000/05/24 J-STAGE公開日: 2010/05/31 受理日: 2000/05/24 早期公開日: - 改訂日: -
訂正情報
訂正日: 2010/05/31 訂正理由: - 訂正箇所: 論文抄録訂正内容: Wrong : Suspended particulate matter (SPM) in the ambient air had been measured with using the two methods, i.e., a β attenuation method (β-ray absorption method; particles larger than 10μm were removed by a cyclon type separator) and a gravimetric high-volume (HV) method (the exposed filters were kept in 50% relative humidity for more than one day before weighing), at two monitoring stations (Ohta and Minato) in Tokyo for a decade (1984-1993) . The measurements were run for 24-hours on randomly selected non-consecutive two days per month.
1) High correlation between the two data sets was observed on the SPM concentrations in each station, [Ohta Sta.; r (correlation coef.) =0.690 (0.529, 0.879) ], [Minato Sta.; r = 0.857 (0.807, 0.907) ], where; the numbers in the parentheses mean the correlation coef. for the periods before and after March in 1991 (when the instruments for a β method were changed) . 2) Linear relationships between the SPM concentrations by an HV and a β method after April in 1991 were;
Ohta Sta.; HV = [1.2-1.4-1.7] ⋅β+ [10-27-34] ………………… (1)
Minato Sta.; HV = [0.9-1.1-1.6] ⋅β+ [3-26-36] …………………… (2)
Where; HV = [α₁-α-α₂] ⋅β+ [γ₁-γ-γ₂],
α&γ: slope & intercept of the line by principal component analysis.
α₁-α₂ & γ₁-γ₂: 95% confidence interval for slope & intercept estimated by a Bootstrap method.
3) The variation patterns of SPM concentration at the two sites were very similar in spite of 8 km distance. 4) SPM concentration was increased under the weather conditions of higher relative humidity and/or weak wind. 5) The difference of values between HV and β was decreased with higher relative humidity (>80%) and/or lower HV value.
In addition, the SPM concentration for HV induced from the relationship showing in eq. (1) and (2) were compared with the HV values in 12 mega-cities in the world.
Right : Suspended particulate matter (SPM) in the ambient air had been measured with using the two methods, i.e., a β attenuation method (β-ray absorption method; particles larger than 10μm were removed by a cyclon type separator) and a gravimetric high-volume (HV) method (the exposed filters were kept in 50% relative humidity for more than one day before weighing), at two monitoring stations (Ohta and Minato) in Tokyo for a decade (1984-1993) . The measurements were run for 24-hours on randomly selected non-consecutive two days per month.
1) High correlation between the two data sets was observed on the SPM concentrations in each station, [Ohta Sta.; r (correlation coef.) =0.690 (0.529, 0.879) ], [Minato Sta.; r = 0.857 (0.807, 0.907) ], where; the numbers in the parentheses mean the correlation coef. for the periods before and after March in 1991 (when the instruments for a β method were changed) . 2) Linear relationships between the SPM concentrations by an HV and a β method after April in 1991 were;
Ohta Sta.; HV = [1.2-1.4-1.7] ·β+ [10-27-34] ………………… (1)
Minato Sta.; HV = [0.9-1.1-1.6] ·β+ [3-26-36] …………………… (2)
Where; HV = [α₁-α-α₂] ·β+ [γ₁-γ-γ₂],
α&γ: slope & intercept of the line by principal component analysis.
α₁-α₂ & γ₁-γ₂: 95% confidence interval for slope & intercept estimated by a Bootstrap method.
3) The variation patterns of SPM concentration at the two sites were very similar in spite of 8 km distance. 4) SPM concentration was increased under the weather conditions of higher relative humidity and/or weak wind. 5) The difference of values between HV and β was decreased with higher relative humidity (>80%) and/or lower HV value.
In addition, the SPM concentration for HV induced from the relationship showing in eq. (1) and (2) were compared with the HV values in 12 mega-cities in the world.

抄録

1984～1993年の10ヵ年間にわたり東京都内の2ヵ所の大気監視局 [大田区大森南 (準工業地域) , 港区白金台 (住宅地域) ] において, , 3線吸収法 (10μm以上の粗大粒子をサイクロンで除去) とハイボリュームエアサンプラー (HV) 法 (湿度50%に調整後, 秤量) で測定した大気中の浮遊粉塵の値を比較した。解析の結果, 2種の測定値の間には全般に高い相関 [大田局; r=0.690 (0.529, 0.879) , 港局; r=0.857 (0.807, 0.907) , () 内はβ線吸収SPM計の交換 (1991年3月) の前期, 後期] が見られ, 1991年4月以降では以下の直線関係式を認めた。
大田局; HV値; [1.2～1.4～1.7] ・β値+ [10～27～34] 港局; HV値= [0.9～1.1～1.6] ・β値+ [3～26～36]
ここで, それぞれの括弧の中の数値は; [ (95%信頼区間の下限値) ～ (直交回帰式 (Linear relationship) の値) ～ (95%信頼区間の上限値) ] を示している。
両局 (南北に約8kmの距離) における浮遊粉塵の濃度変動パターンは類似していたが, 大田局のHV値は港局に較べて粗大粒子の比率が高いためか, β値との相関が低くなった。また, 相対湿度が高く, 風が弱いほどいずれの浮遊粉塵濃度も増大したが, 温度による影響は見られなかった。 [HV-β] 値は, HV値が高いほど増大し, 相対湿度が80%以上になると小さくなる傾向が認められた。
ここで求めた関係を基に連続測定の年間平均β値から算出したHV値, あるいは実測HV値と世界の主要都市のHV値の比較から, 東京の浮遊粉塵の汚染度合いは開発途上国よりも全般に低いことを認めた。

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