The Association between Drought Exposure and Respiratory-Related Mortality in the United States from 2000 to 2018

Abstract

Climate change has brought increasing attention to the assessment of health risks associated with climate and extreme events. Drought is a complex climate phenomenon that has been increasing in frequency and severity both locally and globally due to climate change. However, the health risks of drought are often overlooked, especially in places such as the United States, as the pathways to health impacts are complex and indirect. This study aims to conduct a comprehensive assessment of the effects of monthly drought exposure on respiratory mortality for NOAA climate regions in the United States from 2000 to 2018. A two-stage model was applied to estimate the location-specific and overall effects of respiratory risk associated with two different drought indices over two timescales (the US Drought Monitor and the 6-month and 12-month Evaporative Demand Drought Index). During moderate and severe drought exposure, respiratory mortality risk ratio in the general population increased up to 6.0% (95% Cr: 4.8 to 7.2) in the Northeast, 9.0% (95% Cr: 4.9 to 13.3) in the Northern Rockies and Plains, 5.2% (95% Cr: 3.9 to 6.5) in the Ohio Valley, 3.5% (95% Cr: 1.9 to 5.0) in the Southeast, and 15.9% (95% Cr: 10.8 to 20.4) in the Upper Midwest. Our results showed that age, ethnicity, sex (both male and female), and urbanicity (both metro and non-metro) resulted in more affected population subgroups in certain climate regions. The magnitude and direction of respiratory risk ratio differed across NOAA climate regions. These results demonstrate a need for policymakers and communities to develop more effective strategies to mitigate the effects of drought across regions.

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“…Meanwhile, differences found in this study across district municipalities may be explained by potential differences in the drought exposure as well as in the adaptative capacity and resilience of the populations (e.g. more efficient early warning systems, availability and access to public health services and interventions or better preparation to mitigate drought effects) [4,23].…”

“…more extended droughts). Different characterization of drought events, as well as the use of different drought indices, may also influence drought-related mortality [2,4,23,24]. Meanwhile, differences found in this study across district municipalities may be explained by potential differences in the drought exposure as well as in the adaptative capacity and resilience of the populations (e.g.…”

“…However, evidence suggests that the magnitude and direction of drought-related mortality risk can vary by regions [e.g. 22,23], causes of death [24] and population groups [e.g. [19][20][21]23].…”

“…22,23], causes of death [24] and population groups [e.g. [19][20][21]23]. Factors such as geography, climate, settlement patterns (rural vs. urban), demographic and socioeconomic conditions, culture, and governance can contribute to vulnerability [4,12].…”

“…The United Nations Office for Disaster Risk Reduction indicates that rural communities and farmers tend to be more vulnerable to drought effects, particularly associated with mental health [2], while other studies postulate that people living in urban areas may have higher extreme weather events-related respiratory risks because of the urban heat island effects and higher concentration of pollution from road traffic and industries in urban environments [3,4]. However, a recent study on drought-related respiratory mortality in the United States indicated that non-metro counties were associated with a higher mortality risk ratio and were more susceptible to drought exposure than metro counties [23]. Consequently, further studies are needed to better understand the profiles of the most vulnerable populations.…”