The land-use regression (LUR) approach to estimate the levels of ambient air pollutants is becoming popular due to its high validity in predicting small-area variations. However, only a few studies have been conducted in Asian countries, and much less research has been conducted on comparing the performances and applied estimates of different exposure assessments including LUR. The main objectives of the current study were to conduct nitrogen dioxide (NO2) exposure assessment with four methods including LUR in the Republic of Korea, to compare the model performances, and to estimate the empirical NO2 exposures of a cohort.
The study population was defined as the year 2010 participants of a government-supported cohort established for bio-monitoring in Ulsan, Republic of Korea. The annual ambient NO2 exposures of the 969 study participants were estimated with LUR, nearest station, inverse distance weighting, and ordinary kriging. Modeling was based on the annual NO2 average, traffic-related data, land-use data, and altitude of the 13 regularly monitored stations.
The final LUR model indicated that area of transportation, distance to residential area, and area of wetland were important predictors of NO2. The LUR model explained 85.8% of the variation observed in the 13 monitoring stations of the year 2009. The LUR model outperformed the others based on leave-one out cross-validation comparing the correlations and root-mean square error. All NO2 estimates ranged from 11.3–18.0 ppb, with that of LUR having the widest range. The NO2 exposure levels of the residents differed by demographics. However, the average was below the national annual guidelines of the Republic of Korea (30 ppb).
The LUR models showed high performances in an industrial city in the Republic of Korea, despite the small sample size and limited data. Our findings suggest that the LUR method may be useful in similar settings in Asian countries where the target region is small and availability of data is low.
Department of Public Health Science, Graduate School, Korea University, Republic of Korea;Current address: Department of Epidemiology, University of North Carolina, Chapel Hill, NC, United States of America;School of Forestry and Environmental Studies, Yale University, New Haven, CT, United States of America;Department of Public Health Sciences, Graduate School, Korea University, Seoul, Republic of Korea;Division of Health Policy and Management, College of Health Science, Korea University, Seoul, Republic of Korea;Author to whom any correspondence should be addressed.
Recommended Citation:
Giehae Choi,Michelle L Bell,Jong-Tae Lee. A study on modeling nitrogen dioxide concentrations using land-use regression and conventionally used exposure assessment methods[J]. Environmental Research Letters,2017-01-01,12(4)