The influence of human and environmental exposure factors on personal NO2 exposures

Abstract

The US Environmental Protection Agency's (US EPA) Detroit Exposure and Aerosol Research Study (DEARS) deployed a total of over 2000 nitrogen dioxide, NO 2, passive monitors during 3 years of field data collections. These 24-h based personal, residential outdoor and community-based measurements allowed for the investigation of NO 2 spatial, temporal, human and environmental factors. The relationships between personal exposures to NO 2 and the factors that influence the relationship with community-based measurements were of interest. Survey data from 136 participants were integrated with exposure findings to allow for mixed model effect analyses. Ultimately, 50 individual factors were selected for examination. NO 2 analyses revealed that season, exposure to environmental tobacco smoke and residential gas appliances were strong influencing factors. Only modest associations between community-based measures of nitrogen dioxide and personal exposures impacted by various exposure factors for heating (r ¼ 0.44) or nonheating seasons (r ¼ 0.34) were observed, indicating that use of ambient-based monitoring as a surrogate of personal exposure might result in sizeable exposure misclassification.

Determinants of personal exposure to some carcinogenic substances and nitrogen dioxide among the general population in five Swedish cities

“…In a US study by Williams et al, 2012, persons exposed to ETS showed a significantly higher NO 2 level, at least in winter. 24 In our study, smokers did not have significantly increased exposure levels, but non-smokers exposed to ETS had. However, this increase in exposure was not as distinct as in the US study.…”

An Empirical Assessment of Exposure Measurement Error and Effect Attenuation in Bipollutant Epidemiologic Models

“…Exposures estimated from ambient monitors for these pollutants may be associated with more error than monitor-based estimates for pollutants that are more spatially homogeneous [e.g., fine particulate matter (PM 2.5 ; ≤ 2.5 μm in aerodynamic diameter), sulfate (SO 4 ), ozone (O 3 )]. When exposure estimates do not take into account exposure factors such as time–location–activity patterns (including time spent indoors) (Monn 2001; Setton et al 2011), significant indoor sources [e.g., gas stoves contributing to nitrogen dioxide (NO 2 ) exposures] (Williams et al 2012), or housing characteristics [e.g., air exchange rate (AER), pollutant infiltration] (Sarnat JA et al 2013), exposure error may be greater.…”

Associations between personal exposures to VOCs and alterations in cardiovascular physiology: Detroit Exposure and Aerosol Research Study (DEARS)

“…In particular we defined personal monitoring compliance here with the adherence of wearing the monitoring vest a minimum of 60% of non-sleep hours and being exposed to a maximum of 1.5 mg/m 3 of PM 2.5 -related environmental tobacco smoke (ETS) during each 24 h period. A total of four non-exclusive, participant categories have been distinguished in the DEARS relative to the protocol compliance and ETS exposure characteristics (Williams et al, 2012a). These include an "all-subject" category where no censoring of data relative to their ETS exposure or full compliance in wearing the monitoring vest took place.…”

“…The Detroit Exposure and Aerosol Research Study (DEARS) has proven to be a tremendous resource in defining critical spatial and temporal variability of particulate matter, criteria gas pollutants, volatile organic compounds (VOCs), and other important pollutants at the personal, residential and ambient spatial settings (Stevens et al, 2014;Hammond et al, 2013;Bereznicki et al, 2012;Williams et al, 2012aWilliams et al, , 2012bDuval et al, 2012;George et al, 2011;Brook et al, 2011a). Collecting nearly 36,000 individual (24-hr) based exposure measures, its depth has provided the ability to critically examine how humans are exposed to various pollutants and, in many situations, the impact of these exposure sources upon observable health effects.…”