MRC Centre for Environment and Health, Environmental Research Group, Imperial College London, UK.
MRC Centre for Environment and Health, Environmental Research Group, Imperial College London, UK; NIHR-HPRU Environmental Exposures and Health, School of Public Health, Imperial College London, UK.
Sci Total Environ. 2022 Mar 15;812:152521. doi: 10.1016/j.scitotenv.2021.152521. Epub 2021 Dec 22.
There has been ongoing research aimed at reducing pollution concentrations in vehicles due to the high exposure which occurs in this setting. These studies have found using recirculate (RC) settings substantially reduces in-cabin traffic-related pollution concentrations but possibly leads to an adverse accumulation of carbon dioxide (CO) from driver respiration. The aim of this study was to highlight how vehicle models and ventilation settings affect in-cabin concentrations to ultrafine particles (UFP) and CO in real-world conditions. We assessed the ability of different vehicles to balance reductions in UFP against the build-up of in-cabin CO concentrations by measuring these pollutants concurrently both inside and outside the vehicle to derive an in/out ratio. When ventilation settings were set to RC, UFP concentrations inside the vehicles (median: 3205 pt./cm) were 86% lower compared to outside air (OA) (23,496 pt./cm) across a 30-min real-world driving route. However, CO concentrations demonstrated a rapid linear increase under RC settings, at times exceeding 2500 ppm. These concentrations have previously been associated with decreased cognitive performance. Our study did not find an effect of gasoline fuelled vehicles affecting in-cabin UFP levels compared to hybrid or electric vehicles, suggesting that self-pollution was not an issue. We also found that certain vehicle models were better at reducing both in-cabin UFP and CO concentrations. The results suggest that under RC settings in/out CO ratios are largely determined by the leakiness of the vehicle cabin, whereas in/out UFP ratios are primarily determined by the efficacy of the in-built air filter in the vehicles ventilation system.
由于在这种环境中会发生高暴露，因此一直在进行旨在降低车辆污染浓度的研究。这些研究发现，使用再循环（RC）设置可大大降低车内与交通相关的污染浓度，但可能导致驾驶员呼吸产生的二氧化碳（CO）的不利积累。本研究的目的是强调车辆模型和通风设置如何在实际条件下影响车内超细颗粒（UFP）和 CO 的浓度。我们通过在车内和车外同时测量这些污染物，评估了不同车辆在降低 UFP 浓度与车内 CO 浓度积累之间取得平衡的能力，从而得出内外比。当通风设置为 RC 时，与室外空气（OA）相比，车辆内部的 UFP 浓度（中位数：3205 pt./cm）在 30 分钟的实际驾驶路线中降低了 86%（23496 pt./cm）。然而，CO 浓度在 RC 设置下呈快速线性增加，有时超过 2500 ppm。先前的研究表明，这些浓度与认知能力下降有关。我们的研究没有发现与混合动力或电动汽车相比，汽油燃料汽车会影响车内 UFP 水平，这表明自污染不是一个问题。我们还发现某些车型在降低车内 UFP 和 CO 浓度方面表现更好。结果表明，在 RC 设置下，内外 CO 比主要由车辆座舱的泄漏率决定，而内外 UFP 比主要由车辆通风系统内置空气滤清器的效率决定。
