Exposure to PM1 ups risk of hospitalization for respiratory diseases

Short-term exposure to particulate matter with an aerodynamic diameter ≤1 μm (PM₁) appears to contribute to a higher risk of hospital admission for respiratory diseases (RDs), suggests a study.

Overall, 408,658 hospital admissions for total RDs were documented in this study. Each 10-μg/m³ increase in PM₁ significantly correlated with a 1.39-percent (95 percent confidence interval [CI], 0.87‒1.91) increase in the likelihood of hospital admission for total RDs.

Additionally, each 10-μg/m³ increase in PM₁ induced a 1.97-percent (95 percent CI, 1.06‒2.87) and 1.69-percent (95 percent CI, 0.67‒2.71) greater chances of hospitalization due to chronic obstructive pulmonary disease (COPD) and pneumonia, respectively.

There was a 6.03-percent excess fraction of hospital admission for total RDs attributable to PM₁ exposure, while that for COPD and pneumonia was 6.59 percent and 7.48 percent, respectively. Notably, higher excess fractions of hospitalization for total RDs were more evident among older patients (aged >75 years).

“[The finding] emphasizes the need to pay attention to the effects of PM₁ on respiratory health, especially among elderly patients,” the authors said.

This time-stratified case-crossover study involved patients who had been admitted to the hospital for RDs in Guangdong, China, between 2016 and 2019. Exposure to PM₁ was assessed based on the patient’s residence for each case day and its control days.

The authors used conditional logistic regression models and distributed lag nonlinear models to explore the relationship between PM₁ exposure and hospital admission for RDs at lag 0‒1 day.