High efficiency cabin air filter in vehicles reduces drivers' roadway particulate matter exposures and associated lipid peroxidation

Abstract

Commuters who spend long hours on roads are exposed to high levels of traffic related air pollutants (TRAPs). Despite some well-known multiple adverse effects of TRAPs on human health, limited studies have focused on mitigation strategies to reduce these effects. In this study, we measured fine particulate matter (PM2.5) and ultrafine particle (UFP) concentrations inside and outside 17 taxis simultaneously while they were driven on roadways. The drivers’ urinary monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and malondialdehyde (MDA) concentrations just before and right after the driving tests were also determined. Data were collected under three driving conditions (i.e. no mitigation (NM), window closed (WC), and window closed plus using high efficiency cabin air filters (WC+HECA)) for each taxi and driver. The results show that, compared to NM, the WC+HECA reduced in-cabin PM2.5 and UFP concentrations, by 37% and 47% respectively (p < 0.05), whereas the reductions on PAH exposures were insignificant. Although nonsignificant, a reduction of 17% was also observed in the drivers’ urinary MDA under WC+HECA. The MDA concentrations were found to be significantly associated with the in-cabin PM2.5 and UFP concentrations, suggesting the reduction of the drivers’ lipid peroxidation can be at least partially attributed to the PM2.5 and UFP reduction by WC+HECA. Overall, these results suggest HECA filters have potential to reduce particle levels inside taxis and protect drivers’ health.

Cross‐sectional study of in‐vehicle exposure to ultrafine particles and black carbon inside Lebanese taxicabs

“…In comparison with other studies, UFP levels recorded inside Lebanese taxis were 1.6-fold higher than those measured in Los Angeles. 20 Nevertheless, they were considerably much lower than in-taxis UFP concentrations reported in two distinct studies conducted in London 18,27 and in Barcelona. 28 These differences may be explained first by the variation in the time/duration of measurement.…”

“…WC + AC + ARM offered between 47% and 90% of UFP protection inside cabs. 20,30,40 Furthermore, Onat et al 41 found that UFP levels were 80% higher in vehicles when WO and they were more than doubled in Moreno et al 28 and in Los Angeles (mean: 19 ± 20 μg m −3 ) cars 46 and slightly higher than in Singapore taxis (GM: 2.9 μg m −3 ). 47 Such divergence may be the result of both windows opening/closing status and engine types.…”

“…Very little research to date has studied the effect of smoking especially inside taxi vehicles because smoking inside public transportation is prohibited in numerous areas such as Honk Kong, 31,32 Guangzhou, 33 Sweden, 34 and Foshan, 35 or some teams had excluded smokers to avoid interference with measurements. 20,36 Since smoking is not banned on board of a public transport vehicle in Lebanon, we were able to assess its effect. We found that smoking inside taxicabs, in more than two trips, is responsible for 84% elevation of in-taxis UFP levels.…”

“…17 Therefore, this novel pilot study aimed to measure, for the first time in Lebanon, taxi drivers' exposure to UFP and BC inside their vehicles and to identify its determinants, which so far have been poorly documented. [18][19][20][21]…”

The Solution to Pollution: Is it Technological? [Opinion]

“…Human resources are equally important for ongoing maintenance of monitors, such as general checks, replacing parts, changing filters, recalibration, etc. [12]. Finally, extracted data needs to be ratified through a lengthy curation process, enabling data to be ready for public dissemination and communication.…”