Lioy P J, Wainman T, Zhang J, Goldsmith S
Environmental and Occupational Health Sciences Institute, Exposure Measurement and Assessment Division, Piscataway, New Jersey, USA.
J Air Waste Manag Assoc. 1999 Feb;49(2):200-6. doi: 10.1080/10473289.1999.10463789.
The issue of fine particle (PM2.5) exposures and their potential health effects is a focus of scientific research because of the recently promulgated National Ambient Air Quality Standard for PM2.5. Before final implementation, the health and exposure basis for the standard will be reviewed by the U.S. Environmental Protection Agency within the next five years. As part of this process, it is necessary to understand total particle exposure issues and to determine the relative importance of the origin of PM2.5 exposure in various micro-environments. The results presented in this study examine emissions of fine particles from a previously uncharacterized indoor source: the residential vacuum cleaner. Eleven standard vacuum cleaners were tested for the emission rate of fine particles by their individual motors and for their efficiency in collecting laboratory-generated fine particles. An aerosol generator was used to introduce fine potassium chloride (KCl) particles into the vacuum cleaner inlet for the collection efficiency tests. Measurements of the motor emissions, which include carbon, and the KCl aerosol were made using a continuous HIAC/Royco 5130 A light-scattering particle detector. All tests were conducted in a metal chamber specifically designed to completely contain the vacuum cleaner and operate it in a stationary position. For the tested vacuum cleaners, fine particle motor emissions ranged from 9.6 x 10(4) to 3.34 x 10(8) particles/min, which were estimated to be 0.028 to 176 micrograms/min for mass emissions, respectively. The vast majority of particles released were in the range of 0.3-0.5 micron in diameter. The lowest particle emission rate was obtained for a vacuum cleaner that had a high efficiency (HEPA) filter placed after the vacuum cleaner bag and the motor within a sealed exhaust system. This vacuum cleaner removed the KCl particles that escaped the vacuum cleaner bag and the particles emitted by the motor. Results obtained for the KCl collection efficiency tests show > 99% of the fine particles were captured by the two vacuum cleaners that used a HEPA filter. A series of tests conducted on two vacuum cleaners found that the motors also emitted ultra-fine particles above 0.01 micron in diameter at rates of greater than 10(8) ultra-fine particles/CF of air. The model that had the best collection efficiency for fine particles also reduced the ultra-fine particle emissions by a factor of 1 x 10(3).
由于最近颁布了细颗粒物（PM2.5）的国家环境空气质量标准，细颗粒物（PM2.5）暴露及其潜在健康影响问题成为科学研究的焦点。在最终实施之前，美国环境保护局将在未来五年内对该标准的健康和暴露依据进行审查。作为这一过程的一部分，有必要了解总颗粒物暴露问题，并确定各种微环境中PM2.5暴露源的相对重要性。本研究给出的结果考察了一个此前未作特性描述的室内源——家用吸尘器——的细颗粒物排放情况。对11台标准吸尘器进行了测试，检测其各个电机的细颗粒物排放率以及收集实验室产生的细颗粒物的效率。使用气溶胶发生器将细氯化钾（KCl）颗粒引入吸尘器入口进行收集效率测试。使用连续式HIAC/Royco 5130 A光散射颗粒探测器对包括碳在内的电机排放物以及KCl气溶胶进行测量。所有测试均在一个专门设计的金属室内进行，该金属室能够完全容纳吸尘器并使其在固定位置运行。对于所测试的吸尘器，细颗粒物电机排放率在9.6×10⁴至3.34×10⁸颗粒/分钟之间，据估计质量排放分别为0.028至176微克/分钟。释放的绝大多数颗粒直径在0.3 - 0.5微米范围内。对于一台在吸尘器袋和电机之后设有高效空气过滤器（HEPA）且排气系统密封的吸尘器，其颗粒排放率最低。这台吸尘器能够清除从吸尘器袋中逸出的KCl颗粒以及电机排放的颗粒。KCl收集效率测试结果表明，使用HEPA过滤器的两台吸尘器捕获了超过99%的细颗粒物。在两台吸尘器上进行的一系列测试发现，电机还以大于10⁸超细颗粒/立方英尺空气的速率排放直径大于0.01微米的超细颗粒。对细颗粒物收集效率最佳的型号也将超细颗粒排放量降低了1×10³倍。
