Mortality risks associated with ozone exposure: Modified by temperature and mediating temperature effects.

Area of Science:

• Environmental Health
• Epidemiology
• Toxicology

Background:

• Short-term ozone exposure is linked to increased mortality.
• The interplay between ozone, temperature, and health outcomes requires further investigation.
• Ozone may act as both a temperature-modified factor and a mediator of temperature's health impacts.

Purpose of the Study:

• To examine the associations between short-term ozone exposure and cause-specific mortality.
• To assess whether temperature modifies the ozone-mortality relationship.
• To evaluate ozone's role as a mediator in temperature-related mortality.

Main Methods:

• Time-series study utilizing quasi-Poisson generalized additive models (GAMs).
• Analysis of ozone effects across different temperature strata (low, moderate, high).
• Mediation analysis and subgroup analyses by sex, age, and education.

Main Results:

• Ozone exposure showed positive associations with non-accidental, cardiovascular, and cerebrovascular mortality.
• Ozone's adverse effects were amplified under lower temperature conditions.
• Ozone explained a significant portion of temperature-related mortality (25.21% all-cause, 38.33% cardiovascular).

Conclusions:

• Ozone contributes to mortality through direct effects and by mediating temperature impacts.
• Integrated strategies for ozone control and temperature-health warnings are recommended.
• Vulnerable populations, including older adults and those with lower education, face heightened risks.