PM Concentrations at the Manila Observatory

These figures show monthly updated boxplots of preliminary 24-Hr PM2.5 concentrations collected from the Manila Observatory, Ateneo de Manila University Campus, Loyola Heights Quezon City. Refer to the legend (below) for interpretation of the boxplots. Note the IQR refers to the interquartile range (75th %tile - 25th %tile).

In this most recent chart, PM2.5 values are greatest in the wet season months of July and September 2009. All months have instances with values greater than the daily (24-Hr) standard set by the USEPA.

The boxplots of the PM2.5 collected over 24-Hrs at the Manila Observatory since 2000 show decreased average levels since 2000. Outlier values decreased in magnitude after 2002. Annual averages for all the years were in exceedance of the USEPA Annual Standard Value (15 ug/m3). For most of the years, more than half of the collected data were higher than the revised (2006) USEPA 24-Hr Standard Value (35 ug/m3).