New Year 2009 PM 2.5 Concentrations

Samplers were set up to run for 24 hours, from noon of December 31 to noon of the New Year, in Manila Observatory ( Quezon City ), Barangka ( Marikina ), Valle Verde ( Pasig ), Nangka ( Marikina ) and Oro Vista Royale ( Antipolo City ) for New Year 2009. The measured PM2.5 values in Antipolo and Marikina decreased by almost half of the previous year’s levels (57% and 37% of last year’s levels), and yet greatest PM2.5 values were measured this year in Antipolo (223 ug/m3) and Marikina (186 ug/m3). The lowest PM2.5 values were recorded in MO (124 ug/m3). PM2.5 concentrations in all the sites were in exceedance of the updated 24-hour USEPA guideline value for PM2.5: 35 ug/m3. Prior to 2006, the 24-hour USEPA guideline value for PM2.5 was 65 ug/m3.