Mortality Risk Attributed to Ambient Temperature in Nanjing, China

Area of Science:

• Environmental Health
• Epidemiology
• Public Health

Background:

• Temperature extremes are recognized global health risks.
• Quantifying the burden of moderate temperature exposures is crucial for public health.
• Previous studies have primarily focused on extreme temperature events.

Purpose of the Study:

• To assess the mortality burden attributable to extreme and moderate cold and heat in Nanjing.
• To identify specific temperature ranges associated with the highest mortality fractions.
• To inform public health strategies for temperature-related mortality.

Main Methods:

• Analysis of mortality data (all-cause, cardiovascular, respiratory) in Nanjing from 2010-2016.
• Calculation of attributed mortality fractions for different temperature categories (extreme cold, moderate cold, heat).
• Identification of temperature thresholds associated with peak mortality risks.

Main Results:

• Temperature accounted for 12.81% of all-cause, 19.78% of cardiovascular, and 25.33% of respiratory mortality.
• The highest mortality fractions were observed around 4°C, categorized as moderate cold.
• Moderate cold temperatures, while having lower relative risk (RR) than extreme cold, contributed significantly due to higher frequency.

Conclusions:

• Both extreme and moderate temperature variations contribute to significant mortality in Nanjing.
• Moderate cold presents a substantial, often underestimated, public health challenge.
• Future interventions should consider the impact of frequent moderate cold exposures.