The Impact of Oppressive Weather Conditions on Minority Mortality in Phoenix Adam J Kalkstein Department of Geography Arizona State University Laurence S Kalkstein Department of Geography University of Delaware

Nationwide Heat-Health Watch / Warning Systems These systems are based on much more than just temperature and humidity They are based on actual weather-health relationships, as determined by daily variations in human mortality

Unusual Results for Phoenix Minorities exhibit a late- season spike in summer mortality This is the only case where a portion of the population shows increased mortality late in the summer

Goals To determine what is causing unusual heat-related mortality levels among minorities in Phoenix To create an addition to the current Heat- Health system in Phoenix to warn when potentially dangerous weather conditions exist

Methods This study will examine daily mortality, broken down by race, for the Phoenix Metropolitan Area from May 15 through September 30, The mortality data can then be compared to daily temperature, dew point, and air mass data throughout the summer season to better gauge what is causing the unusual late-season spike in minority mortality.

Data Mortality data –Daily mortality levels for the Phoenix Metropolitan Area, broken down by race (white, black, Mexican Hispanic, non-Mexican Hispanic, other). –For this study, all non-whites are classified as minority

Data Temperature data –Average daily temperature –Average daily dewpoint Air mass data –DP, DM, DT, MP, MM, MT, TR –Since most summer days are either DT or MT, subsets of those air masses are created

Mortality Data Must be Standardized Average daily summer mortality levels in Phoenix ( )

Average Daily Mortality Within Each Air Mass

Thresholds for Increasing Mortality Minorities exhibit a more pronounced dewpoint threshold, at around 13°C

First Clue? The use of evaporative coolers in Phoenix is higher among minority communities. Is it possible that the more humid conditions found later in the summer season cause these evaporative coolers to become ineffective, and thus, increase mortality?

Another Possibility… If these excess deaths are within younger minority populations, this result might indicate that deaths are due to oppressive outdoor working conditions We segregated population into elderly (over 65 years) and non-elderly populations

White Deaths and Dewpoint: MT+ Days No response at all until dewpoints equal 21 degrees C or greater Response is weak even above this dewpoint level; mortality increases about 10 percent among elderly, 8 percent above younger

Minority Deaths and Dewpoint: MT+ Days Much greater negative health response within the non-white community Elderly minority deaths begin to increase significantly at dewpoints equal or exceeding 20 degrees C Increases in mortality top 50 percent in elderly minority population at dewpoints equal or exceeding 21 degrees C Response in elderly population much greater than in younger population

White deaths and Dewpoint: DT+ Days No response regardless of dewpoint

Minority Deaths and Dewpoint: DT+ Days Responses within minority population exceed whites throughout range of dewpoints Elderly response begins to increase significantly at dewpoints equal or exceeding 13 degrees C Under 65 population shows little change in response through entire range of dewpoints Note that DT+ days are hotter than MT+ days

What Does This Mean? Since response is generally found within elderly minority population, we must assume that this is attributed to evaporative cooler inefficiencies rather than outdoor worker deaths Whites show little response for both air masses regardless of dewpoint Any other theories from the "audience"?

What Should We Do About This? There is a need for an evaporative cooler alert system, to be issued by the Phoenix WFO In our opinion, these alerts should be issued based on health outcome rather than discomfort Most deaths above thresholds are not attributed to increased deaths among outdoor workers We need a funding mechanism to develop these evaporative cooler warning systems. NOAA/NWS? Utilities? Local government?