Association between nocturnal ozone enhancement and daily cardiovascular mortality: A multi-city study in China.

ABSTRACT: The health effects of ambient ozone (O₃) pollution have been well documented, but most studies have focused on daytime exposure, with limited research on nighttime O₃. Nocturnal O₃ enhancement (NOE) refers to unexpected increases in nighttime O₃ concentrations over a few hours, yet the health effects of this phenomenon remain unknown. This study evaluated the short-term association between NOE days and cardiovascular mortality by conducting a multi-city time-series analysis in China (2013-2015). Nine definitions were adopted to identify site-level NOE events, considering both average O₃ levels and peak increments at night. A city-level NOE day was defined as a day when over 60% of the monitoring stations within a city recorded at least

SUBMITTER: Jian Z 

PROVIDER: S-EPMC12816898 | biostudies-literature | 2026 Mar

REPOSITORIES: biostudies-literature