Summary of Ambient Air Monitoring (Dioxins) starting from January 2008

Month	Concentration (pg I-TEQ/m3)
Jan-08	0.062
Feb-08	0.080
Mar-08	0.068
Apr-08	0.089
May-08	0.063

Notes: 1. Method of Determination: USEPA Method T09: Method for the Determination of Polychorinated Dibenzo-p-Dioxins (PCDDs) in Ambient Air using High-Resolution Gas Chromatography/High-Resolution Mass Spectrometry (HRGC/HRMS)

2. The Total 2,3,7,8-TCDD Toxicity Equivalence is the product sum of the concentration of all seventeen 2,3,7,8-substituted PCDDs/PCDFs congeners and their respective Toxicity Equivalence Factor (TEF). For those congeners with concentration found below the method detection limit (MDL). half MDL is used for calculation.