Personal Exposure to Black Carbon, Particulate Matter and Nitrogen Dioxide in the Paris Region Measured by Portable Sensors Worn by Volunteers.

Portable sensors have emerged as a promising solution for personal exposure (PE) measurement. For the first time in Île-de-France, PE to black carbon (BC), particulate matter (PM), and nitrogen dioxide (NO2) was quantified based on three field campaigns involving 37 volunteers from the general public wearing the sensors all day long for a week. This successful deployment demonstrated its ability to quantify PE on a large scale, in various environments (from dense urban to suburban, indoor and outdoor) and in all seasons. The impact of the visited environments was investigated. The proximity to road traffic (for BC and NO2), as well as cooking activities and tobacco smoke (for PM), made significant contributions to total exposure (up to 34%, 26%, and 44%, respectively), even though the time spent in these environments was short. Finally, even if ambient outdoor levels played a role in PE, the prominent impact of the different environments suggests that traditional ambient monitoring stations is not a proper surrogate for PE quantification.

Implementation of various hypothetical low emission zone scenarios in Greater Paris: Assessment of fine-scale reduction in exposure and expected health benefits.

OBJECTIVES: Literature assessing the effects of policies aimed at reducing traffic-related air pollution is scarce. The aims of this study were to evaluate the expected impacts, in terms of air quality and health effects, of various hypothetical low-emission zone (LEZ) scenarios in Greater Paris for a planned intervention in 2018/2019 which combine two different perimeters and two levels of vehicles ban, and to assess those impacts according to the socioeconomic status (SES) of the population. METHODS: We evaluated the effects of four hypothetical LEZ scenarios on various stages of the full-chain model, more specifically, road traffic modelling (traffic flow, type of vehicles and related number of kilometers driven), emissions, fine scale PM2.5 and NO2 concentrations, related resident population exposure, and health effects. We computed the overall benefits of expected air pollution improvements in terms of preventable deaths and a decrease in new cases of the following three major chronic diseases: ischemic heart diseases in adults, asthma in children and low weight in full-term newborns. RESULTS: The most stringent LEZ scenario would lower the maximum level of exposure from 55 µg/m3 to 42 µg/m3 in Paris. In one year, this scenario would help prevent: 340 deaths (-0.6%) representing 114,300 life years gained, 170 low-weight full-term births (-4.9%), 130 new cases of ischemic heart disease (IHD) (-1.8%) and 2930 new cases of asthma (-3.0%) among 9.4 million residents. Residents outside the LEZ would also benefit from this scenario. Results indicated that the intervention could contribute to increasing inequalities. The comparison of scenarios underlined the value of extending the LEZ to include a wider zone (including 80 more municipalities surrounding Paris). This would lead to a more equitable spread of the benefits over the population. CONCLUSION: Traffic control policies such as LEZ are difficult to accept for some categories of commuters and economic stakeholders. As of June 2019, the concertation process for the proposed Paris LEZ is still ongoing. This work provides authorities with detailed analyses of the options for this measure as well as information on related implications. It will help decision makers prioritize which preventive measures to introduce.

Wood burning: A major source of Volatile Organic Compounds during wintertime in the Paris region.

Wood burning is widely used for domestic heating and has been identified as a ubiquitous pollution source in urban areas, especially during cold months. The present study is based on a three and a half winter months field campaign in the Paris region measuring Volatile Organic Compounds (VOCs) by Proton Transfer Reaction Mass Spectrometry (PTR-MS) in addition to Black Carbon (BC). Several VOCs were identified as strongly wood burning-influenced (e.g., acetic acid, furfural), or traffic-influenced (e.g., toluene, C8-aromatics). Methylbutenone, benzenediol and butandione were identified for the first time as wood burning-related in ambient air. A Positive Matrix Factorization (PMF) analysis highlighted that wood burning is the most important source of VOCs during the winter season. (47%). Traffic was found to account for about 22% of the measured VOCs during the same period, whereas solvent use plus background accounted altogether for the remaining fraction. The comparison with the regional emission inventory showed good consistency for benzene and xylenes but revisions of the inventory should be considered for several VOCs such as acetic acid, C9-aromatics and methanol. Finally, complementary measurements acquired simultaneously at other sites in Île-de-France (the Paris region) enabled evaluation of spatial variabilities. The influence of traffic emissions on investigated pollutants displayed a clear negative gradient from roadside to suburban stations, whereas wood burning pollution was found to be fairly homogeneous over the region.

A methodology for the characterization of portable sensors for air quality measure with the goal of deployment in citizen science.

The field of small air quality sensors is of growing interest within the scientific community, especially because this new technology is liable to improve air pollutant monitoring as well as be used for personal exposure quantification. Amongst the myriad existing devices, the performances are highly variable; this is why the sensors must be rigorously assessed before deployment, according to the intended use. This study is included in the Polluscope project; its purpose is to quantify personal exposure to air pollutants by using portable sensors. This paper designs and applies a methodology for the evaluation of portable air quality sensors to eight devices measuring PM, BC, NO2 and O3. The dedicated testing protocol includes static ambient air measurements compared with reference instruments, controlled chamber and mobility tests, as well as reproducibility evaluation. Three sensors (AE51, Cairclip and Canarin) were retained to be used for the field campaigns. The reliability of their performances were robustly quantified by using several metrics. These three devices (for a total of 36 units) were deployed to be worn by volunteers for a week. The results show the ability of sensors to discriminate between different environments (i.e., cooking, commuting or in an office). This work demonstrates, first, the ability of the three selected sensors to deliver data reliable enough to enable personal exposure estimations, and second, the robustness of this testing methodology.

Residential Proximity to Heavy-Traffic Roads, Benzene Exposure, and Childhood Leukemia-The GEOCAP Study, 2002-2007.

Childhood leukemia may be associated with traffic-related environmental exposure to benzene, and additional data are needed. The Géolocalisation des Cancers Pédiatriques (GEOCAP) Study, a nationwide French case-control study, was designed to avoid selection bias due to differential participation and misclassification. The study compared the 2,760 childhood leukemia cases diagnosed in France between 2002 and 2007 (including 2,275 cases of acute lymphoblastic leukemia (ALL) and 418 cases of acute myeloblastic leukemia (AML)) with 30,000 contemporaneous child population controls. The residence addresses were precisely geocoded, and 3 indicators of residential proximity to traffic were considered. Estimates of benzene concentrations were also available for the Île-de-France region (including Paris). A 300-m increase in major road length within 150 m of the geocoded address was significantly associated with AML (odds ratio = 1.2, 95% confidence interval: 1.0, 1.4) but not with ALL (odds ratio = 1.0, 95% confidence interval: 0.9, 1.1), and the association was reinforced in the Île-de-France region when this indicator was combined with benzene estimates. These results, which were free from any participation bias and based on objectively determined indices of exposure, showed an increased incidence of AML associated with heavy-traffic road density near a child's home. The results support a role for traffic-related benzene exposure in the etiology of childhood AML.