The Role of Humidity in Associations of High Temperature with Mortality: A Multiauthor, Multicity Study

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F19%3A00509206" target="_blank" >RIV/68378289:_____/19:00509206 - isvavai.cz</a>

Result on the web

<a href="https://ehp.niehs.nih.gov/doi/10.1289/EHP5430" target="_blank" >https://ehp.niehs.nih.gov/doi/10.1289/EHP5430</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1289/EHP5430" target="_blank" >10.1289/EHP5430</a>

Result language

angličtina

Original language name

The Role of Humidity in Associations of High Temperature with Mortality: A Multiauthor, Multicity Study

Original language description

BACKGROUND: There is strong experimental evidence that physiologic stress from high temperatures is greater if humidity is higher. However, heat indices developed to allow for this have not consistently predicted mortality better than dry-bulb temperature. OBJECTIVES: We aimed to clarify the potential contribution of humidity an addition to temperature in predicting daily mortality in summer by using a large multicountry dataset. METHODS: In 445 cities in 24 countries, we fit a time-series regression model for summer mortality with a distributed lag nonlinear model (DLNM) for temperature (up to lag 3) and supplemented this with a range of terms for relative humidity (RH) and its interaction with temperature. City-specific associations were summarized using meta-analytic techniques. RESULTS: Adding a linear term for RH to the temperature term improved fit slightly, with an increase of 23% in RH (the 99th percentile anomaly) associated with a 1.1% [95% confidence interval (CI): 0.8, 1.3] decrease in mortality. Allowing curvature in the RH term or adding terms for interaction of RH with temperature did not improve the model fit. The humidity-related decreased risk was made up of a positive coefficient at lag 0 outweighed by negative coefficients at lags of 1-3 d. Key results were broadly robust to small model changes and replacing RH with absolute measures of humidity. Replacing temperature with apparent temperature, a metric combining humidity and temperature, reduced goodness of fit slightly. DISCUSSION: The absence of a positive association of humidity with mortality in summer in this large multinational study is counter to expectations from physiologic studies, though consistent with previous epidemiologic studies finding little evidence for improved prediction by heat indices. The result that there was a small negative average association of humidity with mortality should be interpreted cautiously: the lag structure has unclear interpretation and suggests the need for future work to clarify. https://doi.org/10.1289/EHP5430.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10509 - Meteorology and atmospheric sciences

Project

<a href="/en/project/GA18-22125S" target="_blank" >GA18-22125S: Modelling weather-to-human health links</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Environmental Health Perspectives

ISSN

0091-6765

e-ISSN

—

Volume of the periodical

127

Issue of the periodical within the volume

9

Country of publishing house

US - UNITED STATES

Number of pages

8

Pages from-to

097007-1-097007-8

UT code for WoS article

000488971900013

EID of the result in the Scopus database

2-s2.0-85072666411