Exploration of NO 2 and PM 2.5 air pollution and mental health problems using high-resolution data in London-based children from a UK longitudinal cohort study.

•High-resolution pollution estimates were successfully combined with cohort data.•Age-12 pollution exposure was not associated with age-12 mental health problems.•But age-12 pollution exposure was significantly associated with age-18 depression.•Associations with depression held even after controlling for common risk factors.•Elevated odds of age-18 conduct disorder among children exposed to air pollution.