Passive ozone network of Dallas: A modeling opportunity with community involvement. 1

Despite tremendous efforts toward regulating and controlling tropospheric o zone (O-3) formation, a large portion of the U.S. population presently live s in environments where air quality exceeds both 1- and 8-h National Ambien t Air Quality Standards (NAAQS) set for O-3 High O-3 concentrations; annual ly cost the United; States billions of dollars in excessive human;health co sts, reduced crop yields,and ecological damage. This paper,describes a regi onal networking of O-3 monitoring sites, operated by the public, that used simplified passive sampling devices (PSDs). In collaboration with EPA Regio n 6, a lay network (i.e., Passive Ozone Network of Dallas, acronym POND), c onsisting of 30 PSD sites in the Dallas-Fort Worth (DFW) Metroplex, a regio n representing 16 counties, successfully measured daily ozone during 8 week s of the 1998 high ozone season. It was demonstrated that the concerned pub lic, when properly trained, could successfully operate a large PSD network that requires daily sample handling and weekly mailing procedures, even fro m remote sites. Data treatment bf the 2880 POND measurements included (i) h igh correlations with collocated continous monitoring data [r range =0.95-0 .97], (ii) daily O-3 contour mapping of the 24 000 km(2) area, and (iii) a ranking of O-3 severity in 12 peri-urban Counties for guidance in siting ad ditional monitors. With a new 8-h NAAQS standard now in place, a cost-effec tive network such as POND could aid regional airshed models in generating m eaningful guidance for O-3 state implementation plans (SIPs) by providing i nput that is: representative of both rural and urban sites.