Climate Change Impacts of Ozone on Morbidity in Vulnerable Populations across the Life Stages in 2050, Mecklenburg County, North Carolina, USA

Abstract

Background: Climate- and emissions-related changes in ozone concentrations will likely impact both morbidity and mortality; these changes may have greater effects on vulnerable populations such as children and older adults. Aims: 1) Estimate the climate- and emissions-related impacts on ozone-related cardiopulmonary morbidity burden from 2006-2011 to 2048-2050 in Mecklenburg County, North Carolina (NC), an urban county in Southeastern United States with over 900,000 residents. 2) Assess the sensitivity of results to alternate population growth and age structure scenarios. Methods: We obtained respiratory and cardiovascular emergency department (ED) visit data from Mecklenburg County for April-October 2006-2011 from the NC Disease Event Tracking and Epidemiologic Collection Tool surveillance system. We estimate baseline ozone-morbidity associations with a time-series model of merged daily ozone monitor data and ED visit counts. We generate projected ozone concentration grids (12km) for 2048-2050 with the Community Multi-scale Air Quality (CMAQ) chemistry transport model using the IPCC A1B emissions scenario and assuming emission changes from anthropogenic sources only . We use a health impact assessment framework to estimate the projected changes in ED visits and the influence of alternate demographic scenarios in 2050. Results: 39,515 eligible ED visits (19,812 cardiovascular, 19,703 respiratory) occurred during the 2006-2011 baseline study period, with mean daily count of 31.5 (SD 7.6). Daily maximum 8-hour average ozone concentrations ranged from 3 to 127 ppb, with median of 51 ppb; May-August 2050 ozone projections indicate decreasing ozone levels, with a median of 36 ppb and range of 18-62 ppb. Baseline associations, projected health impacts, and sensitivity to alternate demographic scenarios will be presented. Conclusions: Climate change, air quality regulation, and population dynamics will likely alter future demand for ED services. These projections can be used to inform local public health preparedness and support continued air pollution mitigation.