Fig. 6
From: The association of exhaled nitric oxide with air pollutants in young infants of asthmatic mothers
1: Summer; 2: autumn/fall; 3: winter; 4: spring; CO: carbon monoxide; eNO50SqR: square root eNO50 (exhaled nitric oxide interpolated to expiratory flow rate 50ml per second); NH3: ammonia; NO: nitric oxide; NO2: nitrogen dioxide; O3: ozone; PM10: particulate matter less than 10μm; PM2.5: particulate matter less than 2.5μm; sinterm: parameterized sine model with assumed value of zero at June, peak in March, and trough in September with increasing amplitude for each year; SO2: sulfur dioxide