Tag Archives: humidity

Absolute Humidity, Temperature, and Influenza Mortality: 30 Years of County-Level Evidence from the United States

TITLE
Absolute Humidity, Temperature, and Influenza Mortality: 30 Years of County-Level Evidence from the United States

AUTHORS
Barreca, Alan, & Jay Shimshack

STATUS
American Journal of Epidemiology | 2012 | 176: S114-S122.

LINK

ABSTRACT
Recent research exploring associations between environmental factors and influenza outcomes has devoted substantial attention to the role of absolute humidity. However, the existing literature provides very little quantitative epidemiologic evidence on the relations between absolute humidity and other weather variables and influenza outcomes in human populations. In the present study, the authors helped fill this gap by analyzing longitudinal weather and influenza mortality data, observed every month between January 1973 and December 2002, for each of 359 urban US counties. A flexible regression model was used to simultaneously explore fully nonlinear relations between absolute humidity and influenza outcomes and temperature and influenza outcomes. Results indicated that absolute humidity was an especially critical determinant of observed human influenza mortality, even after controlling for temperature. There were important nonlinear relations; humidity levels below approximately 6 g of water vapor per kilogram of air were associated with increases in influenza mortality. Model predictions suggested that approximately half of the average seasonal differences in US influenza mortality can be explained by seasonal differences in absolute humidity alone. Temperature modestly influenced influenza mortality as well, although results were less robust.

Climate Change, Humidity, and Mortality in the United States

TITLE
Climate Change, Humidity, and Mortality in the United States

AUTHOR
Barreca, Alan

STATUS
Journal of Environmental Economics and Management | 2012 | 63(1): 19-34.

LINK

ABSTRACT
This paper estimates the effects of humidity and temperature on mortality rates in the United States (c. 1973–2002) in order to provide an insight into the potential health impacts of climate change. I find that humidity, like temperature, is an important determinant of mortality. Coupled with Hadley CM3 climate-change predictions, I project that mortality rates are likely to change little on the aggregate for the United States. However, distributional impacts matter: mortality rates are likely to decline in cold and dry areas, but increase in hot and humid areas. Further, accounting for humidity has important implications for evaluating these distributional effects.