IRAS en het ILM Gerard Hoek Health effects of NO 2 : evidence from recent epidemiological studies Gerard Hoek Institute for Risk Assessment Sciences

Background Health effects of outdoor air pollution well established Main components currently PM 2.5, NO 2 and O 3 Short and long-term exposure effects Least evidence for long-term effects O 3 NO 2 : indicator or direct effects

Presentation Recent evidence on effects of NO2 Contribution of satellite data to exposure assessment for health studies

NO2 results EU limit value Cyrys, AE 2012

Short-term exposure effects

Time series studies of NO2 Since new time series studies on NO2.... Mortality: – All cause 0.5% excess risk per 10 µg/m 3 – Respiratory: 1.8% – Cardiovascular: 1.2% Hospital admissions:1.8%

Time series studies Associations remained after adjusting for other routinely measured pollutants (PM10, PM2.5, CO, SO2, O3) Suggesting an independent role of NO2 But, often no data on ultrafine particles, black carbon which may be more correlated

Hybrid epidemiological –toxicological study: RAPTES Healthy young volunteers at five locations Netherlands with different source characteristics Five hour exposure, moderate exercise On-site exposure assessment (PM, UFP, EC/OC, components, NO2) Pre-post health Single and two pollutant models

Strak. EHP 2012.

RAPTES overall summary Steenhof, 2012NO2 for resp. Inflamm. Strak, 2012NO2 for FEV1,FVC Strak, 2013a,bNO2, SO4, NO3 Thrombin Steenhof,2014NO2 for Lympho, eos. After adjustment for all pollutants

Long-term exposure effects

Cohort studies Variety of exposure assessment methods – Dispersion models – Land use regression models – Nearest monitor – City-wide average Some studies did not account for small-scale variation e.g. American Cancer study

Health effects of long-term exposure to outdoor air pollution > 30 existing cohorts Birth and pregnancy outcomes Respiratory morbidity Cardiovascular morbidity Cancer & mortality 2008 – ESCAPE study

NO2 spatial variation Challenges remain in characterization of spatial variation of NO2 Models used In LUR models characterization of the regional background is problematic

Overall Recent studies continue to show health effects related to NO2 Short and long-term exposure Direct effects of NO2 at ambient levels have become more plausible Satelite data increasingly used, particualrly if scale can be refined