Associations of parental air pollution/greenness exposures with offspring respiratory health: The Life-GAP Project

<bold>Background:</bold> Air pollution and greenness exposures have been linked with personal respiratory health, but their multigenerational effects are still poorly understood. <bold>Aim:</bold> To investigate whether pre-parental residential exposure to air pollution and greenness in adulthood (20-44 yrs.) is associated with asthma status in offspring (4-26 yrs.). <bold>Methods:</bold> We analysed data on 3803 RHINESSA study participants (mean age 19, born after year 1990), who were offspring of 2950 RHINE study participants. Greenness (Normalized Difference Vegetation Index, NDVI) and modelled annual particulate matter (PM2.5, PM10), nitrogen dioxide (NO2), ozone (O3), and black carbon (BC) were assigned to parental residential addresses in 1990. We used two-level (offspring= level 1; parent= level 2) logistic regression with random intercept at level 2, adjusting for centre, offspring’s age and sex, and parental smoking and education. <bold>Results:</bold> In total 8% offspring used asthma medication, 9% had active asthma and 18% reported lifetime asthma. An IQR increase in parental NDVI exposure was associated with 26% lower odds of lifetime asthma in offspring (OR=0.74, 95% CI: 0.57, 0.95). Less precise but similar associations were observed for medication use and active asthma. Despite wide confidence intervals, we observed a tendency for positive association between PM10 and lifetime asthma (1.17, 0.90, 1.60 per IQR). Associations with other air pollutants were inconclusive. <bold>Conclusion:</bold> Parental residential greenness exposure was associated with lower asthma risk in the offspring. This suggest that possible intergenerational health effects should also be considered when planning outdoor environment interventions.