An API reading of between 0 and 50 is considered good, 51 to 100 (moderate), 101 to 200 (unhealthy), 201 to 300 (very unhealthy), and 301 and above (hazardous). We stiil cannot control this annual event of transbordering issue of air pollution. How to stop open burning or forest fire naturally, by accident or purposely burn the forrest!