Association between short-term fine particulate matter exposure and hospital-acquired pneumonia risk in critically ill post-cardiac surgery patients: a 10-year cohort study using distributed lag non-linear models
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background Ambient air pollution (AAP) exposure is a substantial health threat to humans globally. However, whether AAP could promote hospital-acquired pneumonia (HAP) onset in critically ill patients, a vulnerable population undergoing cardiac surgery in the intensive care unit (ICU), remains elusive. This study evaluated the correlation of HAP onset with fine particulate matter (PM 2.5 ). Methods In total, this study included 6,196 patients who underwent cardiovascular surgery at the ICU of a major hospital in Shandong province, China, over 10 years, from January 1, 2014, to December 31, 2023. The daily mean levels of sulfur dioxide (SO 2 ), PM 2.5 , carbon monoxide (CO), PM 10 , and ozone (O 3 ) were assessed from publicly available data. The outcome was HAP, defined according to CDC/NHSN pneumonia criteria as pneumonia developing >48 h after hospital admission and not present or incubating at admission; VAP was not analyzed as a separate endpoint. The association between PM 2.5 and HAP was estimated via a distributed lag non-linear model, adjusted for pollutants, time trends, and weather conditions. Results This study analyzed 1938 (31.278%) HAP cases. The mean levels of PM 10 , O 3 , PM 2.5 , and SO 2 were 120, 75, 59, and 25 μg/m 3 , respectively, and the mean CO level was 0.979 mg/m 3 . The association between PM 2.5 and HAP was statistically significant at lag 1 day within the perioperative exposure window. At a PM 2.5 concentration of 30 μg/m 3 compared with the reference concentration of 10 μg/m 3 , 14.2% higher odds of HAP were observed (95% CI: 2.6–27%). The stratified analyses indicated stronger associations among elders aged ≥ 60 years, patients with body mass index (BMI) > 23.9 kg/m 2 and patients with diabetes. Additional adjustment for clinical covariates, including duration of mechanical ventilation, confirmed the robustness of the observed exposure–response association. Conclusion These findings revealed a substantial and robust link between short-term PM 2.5 exposure and elevated HAP incidence in the vulnerable population undergoing cardiovascular surgeries.
Source: Frontiers in Public Health
Language: English
Subfield: Health, Toxicology and Mutagenesis
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7223176263