Wildfire smoke impacts respiratory health more than fine particles from other sources: observational evidence from Southern California - PubMed (original) (raw)

Wildfire smoke impacts respiratory health more than fine particles from other sources: observational evidence from Southern California

Rosana Aguilera et al. Nat Commun. 2021.

Abstract

Wildfires are becoming more frequent and destructive in a changing climate. Fine particulate matter, PM2.5, in wildfire smoke adversely impacts human health. Recent toxicological studies suggest that wildfire particulate matter may be more toxic than equal doses of ambient PM2.5. Air quality regulations however assume that the toxicity of PM2.5 does not vary across different sources of emission. Assessing whether PM2.5 from wildfires is more or less harmful than PM2.5 from other sources is a pressing public health concern. Here, we isolate the wildfire-specific PM2.5 using a series of statistical approaches and exposure definitions. We found increases in respiratory hospitalizations ranging from 1.3 to up to 10% with a 10 μg m-3 increase in wildfire-specific PM2.5, compared to 0.67 to 1.3% associated with non-wildfire PM2.5. Our conclusions point to the need for air quality policies to consider the variability in PM2.5 impacts on human health according to the sources of emission.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1. Wildfire perimeters in Southern California (1999–2012).

Wildfire perimeters shown here represent the total area burned for a given fire during our study period comprising 1999–2012, excluding summer months (June, July, and August). The inset figure shows the location of our study region, which includes zip codes within the Santa Ana Wind domain in Southern California, USA.

Fig. 2. Mean values of PM2.5 and rate of respiratory admissions by ZIP code.

a Mean PM2.5 concentrations at available zip codes (county boundaries shown in black) and b mean rate of respiratory admissions (per 100,000 individuals) per zip code during 1999–2012 (summer months not considered).

Fig. 3. Wildfire-specific concentrations of PM2.5.

Mean wildfire-specific PM2.5 estimated by a imputation and b seasonal interpolation methods and using the fire upwind and strong SAW exposure definition.

Fig. 4. Wildfire upwind exposure estimation.

The relationship between a given zip code centroid and a fire centroid is assessed by means of geospatial tools. Fires burning upwind are considered within the context of the north-easterly direction of Santa Ana Winds. We use the distance between centroids, as well as the angle of the spatial relationship as shown here, to classify a zipcode day as exposed (or not).

References

1. Reid JS, Koppmann R, Eck TF, Eleuterio DP. A review of biomass burning emissions Part II: intensive physical properties of biomass burning particles. Atmos. Chem. Phys. 2005;5:799–825. doi: 10.5194/acp-5-799-2005. -DOI
1. Liu JC, Pereira G, Uhl SA, Bravo MA, Bell ML. A systematic review of the physical health impacts from non-occupational exposure to wildfire smoke. Environ. Res. 2015;136:120–132. doi: 10.1016/j.envres.2014.10.015. -DOI -PMC -PubMed
1. Gupta P, et al. Impact of California fires on local and regional air quality: the role of a low-cost sensor network and satellite observations. GeoHealth. 2018;2:172–181. doi: 10.1029/2018GH000136. -DOI -PMC -PubMed
1. Gan RW, et al. Comparison of wildfire smoke estimation methods and associations with cardiopulmonary-related hospital admissions. GeoHealth. 2017;1:122–136. doi: 10.1002/2017GH000073. -DOI -PMC -PubMed
1. McClure CD, Jaffe DA. US particulate matter air quality improves except in wildfire-prone areas. Proc. Natl Acad. Sci. USA. 2018;115:7901–7906. doi: 10.1073/pnas.1804353115. -DOI -PMC -PubMed

Wildfire smoke impacts respiratory health more than fine particles from other sources: observational evidence from Southern California - PubMed (original) (raw)