The Impact of Recent Heat Waves on Human Health in California

Abstract

This study examines the health impacts of recent heat waves statewide and for six subregions of California: the north and south coasts, the Central Valley, the Mojave Desert, southern deserts, and northern forests. By using canonical correlation analysis applied to daily maximum temperatures and morbidity data in the form of unscheduled hospitalizations from 1999 to 2009, 19 heat waves spanning 3-15 days in duration that had a significant impact on health were identified. On average, hospital admissions were found to increase by 7% on the peak heat-wave day, with a significant impact seen for several disease categories, including cardiovascular disease, respiratory disease, dehydration, acute renal failure, heat illness, and mental health. Statewide, there were 11 000 excess hospitalizations that were due to extreme heat over the period, yet the majority of impactful events were not accompanied by a heat advisory or warning from the National Weather Service. On a regional basis, the strongest health impacts are seen in the Central Valley and the north and south coasts. The north coast contributes disproportionately to the statewide health impact during heat waves, with a 10.5% increase in daily morbidity at heat-wave peak as compared with 8.1% for the Central Valley and 5.6% for the south coast. The temperature threshold at which an impact is seen varies by subregion and timing within the season. These results suggest that heat-warning criteria should consider local percentile thresholds to account for acclimation to local climatological conditions as well as the seasonal timing of a forecast heat wave.

Climate change, climate justice and the application of probabilistic event attribution to summer heat extremes in the California Central Valley

“…This suggests that other areas of California and Nevada have seen warmer nights than days, consistent with the observations of the CA/NV domain used in Fig. 1 and the extensive analysis on public health impacts carried out by Knowlton et al (2009) andGuirguis et al (2014). The exposure and vulnerability of inhabitants to extreme heat in the more temperate areas like San Francisco presents new problems that must be addressed by policymakers in the region.…”

“…High humidity heat waves, such as the 2006 event, have been found to be especially dangerous, accounting for 66 % of hospitalizations associated with heat waves in the Central Valley (Guirguis et al 2014). Unlike locations such as the eastern US and southeast Europe, the Central Valley is usually very dry during the summer and the model tends to favor high heat and low humidity values for most simulations.…”

The Impact of Energy Consumption on the Surface Urban Heat Island in China’s 32 Major Cities

“…The magnitude of UHI is particularly enhanced in China, which has experienced a rapid urbanization during the last three decades [3,4]. The UHI effect can have impacts on weather and climate [5], increase the energy usage in comparatively hot regions, and impair nearby water quality [6] and the health of urban residents [7,8]. Furthermore, it increases subsurface temperatures and alters the groundwater system both chemically and microbiologically, via geochemical and geobiological reactions under the city [9].…”

Climate Change Trends and Impacts on California Agriculture: A Detailed Review

“…Heat waves occur when temperatures exceed the 99th percentile of its local summertime average for durations of at least 1 to 3 days. People, especially along the coast, that lack air conditioning are vulnerable during extreme heat events [24,25]. Frequent heat waves in the state impact health, economic, ecological, and social parameters, resulting in heat-related deaths and illnesses, decreased agricultural production, increased water use and thus irrigation requirements, and greater electricity demands.…”