Characterization of Ambient PM10 Bioaerosols in a California Agricultural Town

Judith C. Chow; Xufei Yang; Xiaoliang Wang; Steven D. Kohl; Patrick R. Hurbain; L.W. Antony Chen; John G. Watson

doi:10.4209/aaqr.2014.12.0313

Characterization of Ambient PM10 Bioaerosols in a California Agricultural Town

Bioaerosols

Judith C. Chow ¹^,2^,3, Xufei Yang⁴, Xiaoliang Wang¹, Steven D. Kohl¹, Patrick R. Hurbain¹, L.W. Antony Chen¹^,5, John G. Watson¹^,2^,3

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¹Desert Research Institute, 2215 Raggio Parkway, Reno, Nevada 89512, USA
²The State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an, Shaanxi, 710075, China
³Graduate Faculty, University of Nevada, Reno, Nevada 89503, USA
⁴Department of Animal and Food Sciences, University of Delaware, 237 Townsend Hall, Newark, DE 19716, USA
⁵Department of Environmental and Occupational Health, University of Nevada, Las Vegas 89154, USA

Received: December 5, 2014
Revised: February 9, 2015
Accepted: February 21, 2015
Download Citation: ||https://doi.org/10.4209/aaqr.2014.12.0313

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Cite this article:
Chow, J.C., Yang, X., Wang, X., Kohl, S.D., Hurbain, P.R., Chen, L.A. and Watson, J.G. (2015). Characterization of Ambient PM10 Bioaerosols in a California Agricultural Town. Aerosol Air Qual. Res. 15: 1433-1447. https://doi.org/10.4209/aaqr.2014.12.0313

HIGHLIGHTS

Bioaerosols may contribute to high PM₁₀ levels in agricultural communities.
Fungi, pollen, and plant detritus account for 24–33% of OC and 11–15% of PM₁₀ mass.
Commonly used organic biomarkers are not always correlated with fungal spores.

ABSTRACT

Ambient bioaerosols in PM₁₀ samples were measured at three sites in Corcoran, an agricultural town in the southern San Joaquin Valley (SJV) of California, during fall of 2000 corresponding to the cotton harvest season. Elevated bioaerosol concentrations were measured near grain elevators (GRA site) and a cotton handling facility (BAI site) as compared to levels in a residential community (COP site), ~2 km northeast of these sources. Average endotoxin levels (13 ± 17 EU/m³) at the grain elevator site were three to eight times higher than averages at the nearby cotton-handling and residential sites. The highest level (47.6 EU/m³) at the grain elevator site was about half of the exposure limit of 90 EU/m³ set by the Dutch Expert Committee on Occupational Safety. Particle counts of fungal spore (66,333 particles/m³) and pollen grain (2,600 particles/m³) concentrations were more than double those reported in the literature. Average fungal biomarker concentrations of 170 and 131 ng/m³ for arabitol and mannitol, respectively, were 1–2 orders of magnitude higher than those from non-agricultural areas. The low correlation (r < 0.11) of three fungal markers (i.e., (1→3)-β-D-glucan, arabitol, and mannitol) with fungi counts is consistent with findings by others and indicates that these are insufficient as surrogates to represent fungal exposure. Agricultural activities contributed measureable amounts to PM₁₀ mass and organic carbon (OC), dominated by fungal spores (i.e., 5.4–5.8% PM₁₀ mass and 11.5–14.7% OC). The sum of fungal spores, pollen grains, and plant detritus accounted for an average of 11–15% PM₁₀ and 24–33% OC mass. Bioaerosols can be important contributors to PM₁₀ mass in farming communities similar to Corcoran, especially during intense agricultural activities.