TY - JOUR
T1 - Contribution of the in-vehicle microenvironment to individual ambient-source nitrogen dioxide exposure
T2 - The Multi-Ethnic Study of Atherosclerosis and Air Pollution article
AU - Hazlehurst, Marnie F.
AU - Spalt, Elizabeth W.
AU - Nicholas, Tyler P.
AU - Curl, Cynthia L.
AU - Davey, Mark E.
AU - Burke, Gregory L.
AU - Watson, Karol E.
AU - Vedal, Sverre
AU - Kaufman, Joel D.
N1 - Publisher Copyright:
© 2018 Nature America, Inc., part of Springer Nature.
PY - 2018/6/1
Y1 - 2018/6/1
N2 - Exposure estimates that do not account for time in-transit may underestimate exposure to traffic-related air pollution, but exact contributions have not been studied directly. We conducted a 2-week monitoring, including novel in-vehicle sampling, in a subset of the Multi-Ethnic Study of Atherosclerosis and Air Pollution cohort in two cities. Participants spent the majority of their time indoors and only 4.4% of their time (63 min/day) in-vehicle, on average. The mean ambient-source NO2 concentration was 5.1 ppb indoors and 32.3 ppb in-vehicle during drives. On average, indoor exposure contributed 69% and in-vehicle exposure contributed 24% of participants' ambient-source NO2 exposure. For participants in the highest quartile of time in-vehicle (≥1.3 h/day), indoor and in-vehicle contributions were 60 and 31%, respectively. Incorporating infiltrated indoor and measured in-vehicle NO2 produced exposure estimates 5.6 ppb lower, on average, than using only outdoor concentrations. The indoor microenvironment accounted for the largest proportion of ambient-source exposure in this older population, despite higher concentrations of NO2 outdoors and in vehicles than indoors. In-vehicle exposure was more influential among participants who drove the most and for participants residing in areas with lower outdoor air pollution. Failure to characterize exposures in these microenvironments may contribute to exposure misclassification in epidemiologic studies.
AB - Exposure estimates that do not account for time in-transit may underestimate exposure to traffic-related air pollution, but exact contributions have not been studied directly. We conducted a 2-week monitoring, including novel in-vehicle sampling, in a subset of the Multi-Ethnic Study of Atherosclerosis and Air Pollution cohort in two cities. Participants spent the majority of their time indoors and only 4.4% of their time (63 min/day) in-vehicle, on average. The mean ambient-source NO2 concentration was 5.1 ppb indoors and 32.3 ppb in-vehicle during drives. On average, indoor exposure contributed 69% and in-vehicle exposure contributed 24% of participants' ambient-source NO2 exposure. For participants in the highest quartile of time in-vehicle (≥1.3 h/day), indoor and in-vehicle contributions were 60 and 31%, respectively. Incorporating infiltrated indoor and measured in-vehicle NO2 produced exposure estimates 5.6 ppb lower, on average, than using only outdoor concentrations. The indoor microenvironment accounted for the largest proportion of ambient-source exposure in this older population, despite higher concentrations of NO2 outdoors and in vehicles than indoors. In-vehicle exposure was more influential among participants who drove the most and for participants residing in areas with lower outdoor air pollution. Failure to characterize exposures in these microenvironments may contribute to exposure misclassification in epidemiologic studies.
KW - In-vehicle exposure
KW - Microenvironment
KW - Traffic-related air pollution
UR - http://www.scopus.com/inward/record.url?scp=85042858208&partnerID=8YFLogxK
U2 - 10.1038/s41370-018-0025-1
DO - 10.1038/s41370-018-0025-1
M3 - Article
C2 - 29511286
AN - SCOPUS:85042858208
SN - 1559-0631
VL - 28
SP - 371
EP - 380
JO - Journal of Exposure Science and Environmental Epidemiology
JF - Journal of Exposure Science and Environmental Epidemiology
IS - 4
ER -