Changes in air quality in‐taxis and in working conditions of taxi drivers pre‐ and post‐lockdown, during the COVID‐19 pandemic in the Paris area

Abstract

The Coronavirus disease 2019 (COVID-19) has threatened the whole of humankind across the globe from environmental, economic, social, and health perspectives. 1,2 All countries have faced tremendous challenges to contain the spread of the disease and to prevent the saturation of health systems. Following the COVID-19 outbreak, restrictive measures, such as border closures, factory shutdowns, traffic restrictions, teleworking, were imposed by many national governments. 3 Under these circumstances, daily activities of populations were limited which resulted in the reduction of some anthropogenic emissions. 4,5 Researchers took advantage of this unprecedented opportunity to assess changes in air pollution. By comparing conditions before and during the COVID-19 pandemic, a remarkable improvement in air quality was reported in many countries, for example,

The impact of COVID-19 lockdown restrictions on the short-term association between in-vehicle particulate pollutants and the respiratory health of Parisian taxi drivers

“…As previously published ( 8 ), the mean concentrations of in-vehicle UFP and BC during working days decreased 1.7 times and 1.4 times post- compared to pre-lockdown, respectively. These results may be explained by the sudden decline in anthropogenic emissions during lockdown and remaining post-lockdown, in particular traffic flow (pre-lockdown: mean 778 (SD 44) versus post-lockdown: mean 703 (SD 90) vehicles per working hours; P<0.0001, Wilcoxon test for paired sample) ( 8 ).…”

“…As previously published ( 8 ), the mean concentrations of in-vehicle UFP and BC during working days decreased 1.7 times and 1.4 times post- compared to pre-lockdown, respectively. These results may be explained by the sudden decline in anthropogenic emissions during lockdown and remaining post-lockdown, in particular traffic flow (pre-lockdown: mean 778 (SD 44) versus post-lockdown: mean 703 (SD 90) vehicles per working hours; P<0.0001, Wilcoxon test for paired sample) ( 8 ). Indeed, since outdoor air pollutants enter vehicles, the decrease in particulate matter concentrations inside taxi vehicles can be partially attributable to the clear enhancement in ambient air quality as a result of restrictions implemented during COVID-19 lockdown ( 23 – 25 ).…”

“…Indeed, since outdoor air pollutants enter vehicles, the decrease in particulate matter concentrations inside taxi vehicles can be partially attributable to the clear enhancement in ambient air quality as a result of restrictions implemented during COVID-19 lockdown ( 23 – 25 ). The reduction of in-vehicle UFP was also due to the variation of ventilation settings ( 8 ) as opening/closing windows and activating air recirculation are known determinants of in-vehicle UFP ( 12 , 20 , 26 – 28 ).…”

“…As a result, a remarkable decrease in outdoor air pollutant concentrations [nitrogen dioxide (NO 2 ), carbon monoxide (CO), sulfur dioxide (SO 2 ), particulate matter (PM 2.5 , PM 10 )] was observed (4-7). Hachem et al (8) also reported a significant (31-32%) reduction in ultrafine particle (UFP, <100 nanometers) and black carbon (BC) concentrations inside taxi vehicles after the first lockdown in the Paris area. This was mainly due to the decrease in traffic flow following the restrictions implemented during COVID-19 lockdown (8).…”

“…Hachem et al (8) also reported a significant (31-32%) reduction in ultrafine particle (UFP, <100 nanometers) and black carbon (BC) concentrations inside taxi vehicles after the first lockdown in the Paris area. This was mainly due to the decrease in traffic flow following the restrictions implemented during COVID-19 lockdown (8).…”