Outdoor near-roadway, community and residential pollen, carbon dioxide and particulate matter measurements in the urban core of an agricultural region in central CA

• Published in: Atmospheric environment (1994) 2012-04, Vol.50, p.103-111
• Main Authors: Shendell, Derek G., Therkorn, Jennifer H., Yamamoto, Naomichi, Meng, Qingyu, Kelly, Sarah W., Foster, Christine A.
• Format: Article
• Language: English
• Subjects: air; air quality; asthma; atmospheric chemistry; Carbon dioxide; container-grown plants; cooling; diurnal variation; education; environmental management; flowers; grasses; income; monitoring; national parks; Near roadway measurements; Particulate matter; particulates; Pollen; pollination; relative humidity; samplers; Spatial heterogeneity; trees; wind speed
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2011.12.056

We can control asthma through proper clinical and environmental management and education. The U.S. population is growing, urbanizing and aging; seniors of low-to-middle income families are working and living longer. We conducted community-based participatory research in Visalia, Tulare County, California with a prospective, cross-sectional repeated measures design and quantitative and qualitative process; home environment and health-related outcomes data were collected. In this paper, we presented results of the air quality sampling—pollen, carbon dioxide (CO2) and particulate matter (PM) outdoors away from most major sources (agricultural fields, large pollinating trees, etc)—at a community central site close to a mobile line source and participant homes in the cooling season, July, 2009. Weather was hot and dry with light winds; diurnal variation ranged between 65–107°F (18–42°C) and 12–76% relative humidity at the study’s central site. Co-located active (reference) and passive (PAAS) samplers were used for pollen; passive monitoring for CO2 (Telaire 7001) and active sampling for PM were conducted. Overall, we observed spatial variability in CO2, fine PM (PM2.5), and pollen counts. Weekday and study week average CO2 and PM2.5 concentrations were higher near study homes compared to central site sampling points, but peak measures and overnight/pre-dawn time period averages were elevated at the central site. Pollen counts were typically lower at homes—even if grass, trees, flowers or potted plants were present—compared to the central site closer to and generally downwind from commercial agricultural tree production. Data are new; the nine-county San Joaquin Valley has one pollen count station in the national network, and two of four government outdoor air monitoring stations in the county are in national parks. We suggest—given poor air quality in large part due to PM—adding routine pollen counts to regional/state agency air monitoring sites and more CO2 and PM monitoring. ► Weekday and study week mean CO2 and PM2.5 concentrations were higher near homes. ► Daily peak measures, however, were elevated at a central site near the freeway. ► Overnight/pre-dawn time period averages were elevated at a central site (SJVC). ► Residential pollen counts were lower than SJVC near agricultural tree production. ► Outdoor central site air quality alone insufficiently describes exposure in homes.