Table 3.

Multilevel Model Parameter Estimates for Nitrogen Dioxide Levels at School on Children's Cognitive Performance, With Further Adjustment for Aircraft and Road Traffic Noise Exposure at School, in the United Kingdom Air Pollution Subsample of the RANCH Project, 2001–2003 (n = 719)

Variable	No. of Participants	Air Pollution at School Adjusted for Sociodemographic Factorsa			Air Pollution, Aircraft Noise, and Road Traffic Noise at School Adjusted for Sociodemographic Factorsa
		βb	95% CI	P Value	βb	95% CI	P Value
Reading comprehension	651
Nitrogen dioxide		0.00041	−0.013, 0.014	0.95	0.004	−0.009, 0.018	0.53
Road traffic noise					−0.004	−0.019, 0.012	0.65
Aircraft noise					−0.012*	−0.023, −0.000063	0.05
Recognition memory	641
nitrogen dioxide		−0.005	−0.041, 0.031	0.78	0.012	−0.021, 0.044	0.48
Road traffic noise					−0.016	−0.054, 0.022	0.40
Aircraft noise					−0.045*	−0.073, −0.017	<0.01
Information recall	638
Nitrogen dioxide		0.012	−0.036, 0.061	0.62	0.015	−0.033, 0.062	0.54
Road traffic noise					0.036	−0.020, 0.092	0.21
Aircraft noise					−0.043*	−0.086, −0.000036	0.05
Conceptual recall	636
Nitrogen dioxide		−0.002	−0.015, 0.011	0.79	0.00023	−0.012, 0.013	0.97
Road traffic noise					0.007	−0.008, 0.022	0.34
Aircraft noise					−0.015*	−0.026, −0.003	0.01
Working memory	580
Nitrogen dioxide		0.036	−0.174, 0.246	0.74	0.003	−0.295, 0.301	0.98
Road traffic noise					0.034	−0.141, 0.209	0.70
Aircraft noise					0.00086	−0.109, 0.111	0.99

Abbreviations: CI, confidence interval; RANCH, Road Traffic and Aircraft Noise Exposure and Children's Cognition and Health.

* P ≤ 0.05.

^a All models were adjusted for age, gender, employment status, crowding, home ownership, mother's educational level, long-standing illness, main language spoken at home, parental support for schoolwork, and classroom window glazing type.

^b Per 1-dB increase in road traffic noise or aircraft noise or a 1-point increase in nitrogen dioxide (μg/m³).