Sagona Jessica A, Shalat Stuart L, Wang Zuocheng, Ramagopal Maya, Black Kathleen, Hernandez Marta, Mainelis Gediminas
Department of Environmental Sciences, Rutgers University, 14 College Fa rm Rd., New Brunswick, NJ 08901.
Department of Environmental and Occupational Medicine, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ 08901 ; Environmental and Occupational Health Sciences Institute, Rutgers University, 170 Frelinghuysen Rd., Piscataway, NJ 08854.
J Aerosol Sci. 2015 Jul 1;85:30-41. doi: 10.1016/j.jaerosci.2015.03.001.
Development of asthma in young children may be associated with high exposure to particulate matter (PM). However, typical stationary samplers may not represent the personal exposure of children ages 3 and younger since they may not detect particles resuspended from the floor as children play, thus reducing our ability to correlate exposure and disease etiology. To address this, an autonomous robot, the Pretoddler Inhalable Particulate Environmental Robotic (PIPER) sampler, was developed to simulate the movements of children as they play on the floor. PIPER and a stationary sampler took simultaneous measurements of particle number concentration in six size channels using an optical particle counter and inhalable PM on filters in 65 homes in New Jersey, USA. To study particle resuspension, for each sampler we calculated the ratio of particle concentration measured while PIPER was moving to the average concentration of particles measured during a reference period when PIPER remained still. For all investigated particle sizes, higher particle resuspension was observed by PIPER compared to the stationary sampler. In 71% of carpeted homes a more significant (at the α = 0.05 level) resuspension of particles larger than 2.5 μm was observed by PIPER compared to the stationary sampler. Typically, particles larger than 2.5 μm were resuspended more efficiently than smaller particles, over both carpeted and bare floors. Additionally, in carpeted homes estimations of PM mass from the particle number concentrations measured on PIPER while it was moving were on average a factor of 1.54 higher compared to reference period when PIPER was not moving. For comparison, the stationary sampler measured an increase of PM mass by a factor of only 1.08 when PIPER was moving compared to a reference period. This demonstrates that PIPER is able to resuspend particles through movement, and provide a better characterization of the resuspended particles than stationary samplers. Accurate measurement of resuspended PM will improve estimates of children's total PM exposure.
幼儿哮喘的发生可能与高暴露于颗粒物（PM）有关。然而，典型的固定采样器可能无法代表3岁及以下儿童的个人暴露情况，因为它们可能无法检测到儿童玩耍时从地板上重新悬浮起来的颗粒，从而降低了我们将暴露与疾病病因联系起来的能力。为了解决这个问题，开发了一种自主机器人——幼儿可吸入颗粒物环境机器人（PIPER）采样器，以模拟儿童在地板上玩耍时的动作。PIPER和一个固定采样器使用光学粒子计数器，在美国新泽西州65户家庭中，同时对六个尺寸通道的颗粒数浓度以及过滤器上的可吸入PM进行了测量。为了研究颗粒再悬浮情况，对于每个采样器，我们计算了PIPER移动时测得的颗粒浓度与PIPER静止时参考期内测得的颗粒平均浓度之比。对于所有研究的粒径，与固定采样器相比，PIPER观察到更高的颗粒再悬浮。在71%铺有地毯的家庭中，与固定采样器相比，PIPER观察到大于2.5μm的颗粒有更显著（在α = 0.05水平）的再悬浮。通常，大于2.5μm的颗粒比小颗粒在铺有地毯的地板和裸地板上更有效地重新悬浮。此外，在铺有地毯的家庭中，PIPER移动时根据其测得的颗粒数浓度估算的PM质量，与PIPER不移动的参考期相比，平均高出1.54倍。相比之下，当PIPER移动时，固定采样器测得的PM质量仅比参考期增加了1.08倍。这表明PIPER能够通过移动使颗粒重新悬浮，并且比固定采样器能更好地表征重新悬浮的颗粒。准确测量重新悬浮的PM将改善对儿童总PM暴露的估计。
