Annual and seasonal spatial models for nitrogen oxides in Tehran, Iran.
Very few land use regression (LUR) models have been developed for megacities in low- and middle-income countries, but such models are needed to facilitate epidemiologic research on air pollution. We developed annual and seasonal LUR models for ambient oxides of nitrogen (NO, NO2, and NOX) in the Middle Eastern city of Tehran, Iran, using 2010 data from 23 fixed monitoring stations. A novel systematic algorithm was developed for spatial modeling. The R(2) values for the LUR models ranged from 0.69 to 0.78 for NO, 0.64 to 0.75 for NO2, and 0.61 to 0.79 for NOx. The most predictive variables were: distance to the traffic access control zone; distance to primary schools; green space; official areas; bridges; and slope. The annual average concentrations of all pollutants were high, approaching those reported for megacities in Asia. At 1000 randomly-selected locations the correlations between cooler and warmer season estimates were 0.64 for NO, 0.58 for NOX, and 0.30 for NO2. Seasonal differences in spatial patterns of pollution are likely driven by differences in source contributions and meteorology. These models provide a basis for understanding long-term exposures and chronic health effects of air pollution in Tehran, where such research has been limited.
Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.|University of Basel, Basel, Switzerland.
Heresh
H
Amini
Research Center for Environmental Pollutants, Qom University of Medical Sciences, Qom, Iran.|Department of Epidemiology and Biostatistics, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran.
Seyed-Mahmood
SM
Taghavi-Shahri
Environmental Health Services, British Columbia Centre for Disease Control, Vancouver, Canada.|School of Population and Public Health, University of British Columbia, Vancouver, Canada.
Sarah B
SB
Henderson
Mechanical Engineering Department, Sharif University of Technology, Tehran, Iran.
Vahid
V
Hosseini
Tehran Air Quality Control Co., Tehran Municipality, Tehran, Iran.
Hossein
H
Hassankhany
Tehran Air Quality Control Co., Tehran Municipality, Tehran, Iran.
Maryam
M
Naderi
Tehran Air Quality Control Co., Tehran Municipality, Tehran, Iran.
Solmaz
S
Ahadi
Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.|University of Basel, Basel, Switzerland.
Christian
C
Schindler
Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.|University of Basel, Basel, Switzerland.
Nino
N
Künzli
Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran.
Masud
M
Yunesian