云南宣威地区燃煤排放PM10的微观形貌和粒度特征

宣威地区肺癌发病率居全国首位,并且肺癌与室内燃煤关系密切. 为了解宣威地区室内燃煤排放PM₁₀的微观形貌和粒度特征,使用小流量Minivol采样器,分别于2011年1月、3月和12月对宣威地区6个代表性乡镇的18个农户及对照点——贵州六盘水幸福村2个农户室内、外的PM₁₀进行采样. 采用扫描电子显微镜分析样品的微观形貌,并对颗粒物粒度进行统计分析. 根据微观形貌特征将PM₁₀分为烟尘集合体(链状、蓬松状、密实状)、球形颗粒(燃煤飞灰和焦油球)、矿物颗粒(规则和不规则状)、生物颗粒及超细未知颗粒. 结果表明:宣威地区室内PM₁₀微观形貌差别较大；室、内外PM₁₀的粒度分布在0.1~0.4μm内的颗粒数量所占比例较大,而1μm以上颗粒体积所占比例较大；小粒径颗粒对颗粒物数量贡献较大,而少数大粒径颗粒对体积贡献较大；宣威地区和对照点室内的PM₁₀数量-粒度和体积-粒度分布相似,室外PM₁₀数量-粒度特征相似但体积-粒度分布有所差异. 宣威地区室内的烟尘集合体和球形颗粒分别占颗粒物总数的10.5%和23.6%,高于对照点 (分别为7.7%和11.3%). 

Microscopic Morphology and Size Distribution of PM10 from Indoor Coal-Burning Emission in Xuanwei, Yunnan Province

The Xuanwei City in Yunnan Province is known to have the highest occurrence rates of lung cancer in China. Previous studies have revealed that the lung cancer incidence in this area was associated with indoor coal burning. During January, March and December 2011, indoor and corresponding outdoor PM₁₀ samples were collected from 18families located in different towns in Xuanwei City, and 2families in Xingfu Village of Liupanshui City in Guizhou Province as the control group by Minivol samplers. Morphologies and size distributions of PM₁₀ samples were determined using the field emission scanning electron microscopy (FESEM) and image analysis (IA). According to the morphology, the particles were classified into soot (e.g., chain, fluffy and compact), spherical (e.g., fly ash and tar ball), mineral (e.g., regular and irregular), biological and ultrafine categories. The number-size distributions showed that indoor and outdoor PM₁₀ in Xuanwei City mainly ranged from of 0.1-0.4μm. The volume-size distributions revealed that indoor and outdoor PM₁₀ in Xuanwei City display their major size ranges between 1-10μm. Fine particles dominated by number, while coarse particles riched by volume in the PM₁₀ of Xuanwei City. The particle distributions by number-size and volume-size in Xuanwei City were similar to that in Xingfu Village. There was only one exception that the volume-size distribution of outdoor PM₁₀ in Xuanwei City had a certain difference from that in Xingfu Village. In the Xuanwei City indoor PM₁₀ number percentages of spherical particles and soot were 23.6% and 10.5% respectively, and these values were higher than those in the Xingfu Village with proportions of 11.3% and 7.7% respectively.