In Reply We thank Fuller-Thomson and Munro for their thoughtful comments on our recent study,1 which identified robust associations between several outdoor air pollutants and adolescent psychotic experiences using data from the Environmental Risk (E-Risk) Longitudinal Twin Study. A 2-pollutant model, including fine particulate matter with aerodynamic diameters of less than 2.5 and nitrogen oxides (NOx), showed that associations were driven by nitrogen species. Road vehicle emissions (particularly from diesel engines) are the primary source of nitrogen species such as NOx and nitrogen dioxide (NO2) in cities. Our findings provide initial evidence that air pollution levels could contribute to the well-established association between urban living and psychosis.