Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Seasonal variation in death rate from coronary artery disease, average temperature, death rate from respiratory infection, and hours of sunlight by month 1984-93. Grey lines represent monthly rates and black lines three month moving averages. All curves display significant annual periodicity (P<0.001)
