Impact of Ozone Exposure of Lung Donors and Recipients on All-Cause Mortality after Lung Transplant

T. Egan¹, S. Arunachalam², C. Chang², P. Strassle¹

¹Surgery, UNC at Chapel Hill, Chapel Hill, NC, ²Institute of the Environment, UNC at Chapel Hill, Chapel Hill, NC

Meeting: 2020 American Transplant Congress

Abstract number: 85

Keywords: Lung, Lung transplantation, Outcome, Survival

Session Information

Session Name: From Bench to Community to Bedside in Lung Transplantation

Session Type: Oral Abstract Session

Date: Saturday, May 30, 2020

Session Time: 3:15pm-4:45pm

Presentation Time: 3:51pm-4:03pm

Location: Virtual

*Purpose: A Belgian study found proximity to a motorway increased risk of bronchiolitis obliterans syndrome after lung transplant (LT). Using zip codes as a surrogate for habitat location, we investigated the impact of ozone exposure of donors and recipients on mortality after LT in the US.

*Methods: UNOS Standard Transplant Analysis and Research (STAR) database (June 30, 2017) identified adult LT recipients and their donors between 2005 and 2015, and their zip code of residence at LT. Daily maximum 8-hour average ozone concentration (MDA8O3) associated with donor and recipient residencies 1 year prior to and after LT respectively, were estimated by mapping each zip code to a census tract, using a crosswalk from HUD, downscaled from a 12×12-km sq grid resolution detailed chemistry – transport model application using a Bayesian space-time downscaler, and then fused with surface observations. Ozoneconcentration was classified into low (<35 parts/billion (ppb)), medium (35-42 ppb) and high (>42 ppb) exposure categories. Cox proportional hazards regression and Kaplan-Meier curves assessed the impact of ozoneon 1-year and long-term all-cause mortality.

*Results: 17,760 LT were analyzed. Median follow-up was 1101 days (IQR 511-2073, range 1-4448). 22% of LT had high donor exposure and 20% had high recipient exposure. Recipient ozone exposure after LT had minimal impact on 1-year mortality; however, higher ozoneconcentration was associated with increased all-cause mortality (Figure). Compared to low exposure, medium (HR 1.13, 95% CI 1.05, 1.22) and high (HR 1.28, 95% CI 1.17, 1.40) both increased patient risk of death. Donor ozoneexposure in the year before LT did not appear to impact LT outcomes (Table).

*Conclusions: Ozone exposure is associated with increased long-term risk of death after LT. Ozone is only one aspect of air quality. Additional research on other air quality measures focusing on traffic-related air pollutants is needed.

Association between ozone concentration of donor and recipient on outcomes after LT
		Donor Exposure		Recipient Exposure
		HR (95% CI)^a	p-value	HR (95% CI)^a	p-value
1-year mortality	Low (for both)	ref		ref
	Medium	1.18 (1.02, 1.35)	0.02	1.07 (0.92, 1.23)	0.39
	High	0.99 (0.84, 1.17)	0.92	1.15 (0.98, 1.35)	0.09
Long-term mortality	Medium	1.05 (0.97, 1.13)	0.21	1.13 (1.05, 1.22)	0.002
	High	1.06 (0.98, 1.16)	0.15	1.28 (1.17, 1.40)	<0.0001
Abbreviations: HR, hazard ratio; CI, confidence interval. ^a Inverse-probability of treatment weights were used to account for potential confounding; weights included recipient age, gender, race/ethnicity, primary payer, total days on waitlist, single vs. double lung transplant, status at transplant (ICU, hospitalized, at home), life support (ventilator and ECMO), recipient and donor cigarette history, donor cause of death, and year of transplant.

To cite this abstract in AMA style:

Egan T, Arunachalam S, Chang C, Strassle P. Impact of Ozone Exposure of Lung Donors and Recipients on All-Cause Mortality after Lung Transplant [abstract]. Am J Transplant. 2020; 20 (suppl 3). https://atcmeetingabstracts.com/abstract/impact-of-ozone-exposure-of-lung-donors-and-recipients-on-all-cause-mortality-after-lung-transplant/. Accessed May 11, 2025.

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