Application of Joint Urban 2003 observations for assessment of morbidity outcomes during a heat wave

During the Joint Urban 2003 Field Experiment, high-density observations of atmospheric conditions were measured via a observational network installed in the central business district of Oklahoma City. During JU2003, a heat wave occurred from 10 July 2003 extending through 22 July 2003 whereby maximum temperature values in the urban core exceeded 35.5 degrees Celsius each day during the event and included two subsequent days with maximum temperatures of 40.5 degrees Celsius. On July 22, a cool front passed through OKC initiating a period of cooler temperatures following the heat wave. Thus, this study included a period yielding an extended heat wave (July 10-21) with a 3-day period (July 19-21) of sustained, extreme temperatures over 38 degrees Celsius.

To understand the health-related impact of the heat wave on the urban population, the study reconstructed the atmospheric environmental conditions alongside the combined analysis of ozone concentrations, meteorological measurements, and social-cultural attributes. Census-based demography and ethnographic analysis were integrated with environmental information in a GIS framework to classify vulnerability of the urban population to adverse health outcomes. Diseases of interest were restricted to acute morbidities, and included hospitalizations for pulmonary diseases, cardiovascular diseases, endocrine diseases, cerebrovascular diseases, psychiatric diseases, and heat specific outcomes (e.g., dehydration, heat stress, heat stroke). Patient address was used to locate the residential location of patients and records were aggregated according to census tracts. Results from this study demonstrated the key relationships between heating, ozone concentrations, and the variability of the impact spatially and temporally. Further, the analyses revealed the geographic variability of urban vulnerability and provided information on the period of susceptibility as related to temporal frame of the heat event and the impact of additional risk factors (air quality, societal factors).