Odds ratio for presenting to an emergency department with non-specific abdominal pain associated with an interquartile increase in an air pollutant concentration on the same day of ED visit stratified by gender among individuals aged 15–24 years.

OR – odds ratio; CI – confidence interval; CO- carbon monoxide; NO2 – nitrogen dioxide; SO2 - sulphur dioxide; O3 - ozone; PM10 - particulate matter <10 microns; PM2.5 - particulate matter <2.5 microns; PPM - parts per million; PPB - parts per billion; mg/m3 - micrograms per meters cubed.