The Influence of Meteorological Parameters and Air Polution on Emergency Hospitalization Visits of Cardiovascular and Respiratory Diseases in Coastal Bend, Texas

Cardiovascular diseases and Respiratory diseases are the leading causes of death globally. The objective of this thesis is to investigate the associations between meteorological parameters, air pollution, and emergency department (ED) visits for Cardiovascular and Respiratory diseases, respectively in Coastal Bend, Texas. A complete ED Hospitalization visits data were obtained from the local hospital systems through 1 October 2010 to 31 August 2012. There were 58,665 visits diagnosed as Respiratory diseases and 18,252 visits diagnosed as Cardiovascular diseases. Air pollution data were obtained from the Environmental Protection Agency (EPA) and meteorological parameter data were downloaded from Weather Underground website. Generalized additive models (GAM) were applied to Respiratory diseases, while generalized linear models (GLM) were applied to Cardiovascular diseases. These models with the controlling for different time trends aimed to explore the associations of meteorological parameters and air pollution with daily counts of ED visits. The impact of the warm as well as the cold seasons and spatial differences were also examined. Distributed lag nonlinear models (DLNM) were applied to explore the effects of the air pollutants and meteorological parameters on the current day (lag 0) morbidity to the first seven days (lag 7). The study area is divided into three sub areas and their spatial variances on the influence of meteorological parameters on Cardiovascular and Respiratory diseases were also explored. Our main findings on Cardiovascular diseases are air pollutants like PM2.5, PM10 and meteorological parameters like Temperature, Relative Humidity, and Precipitation have significant associations with ED visits of Cardiovascular. The influence of PM10 and SO2 both decreases during the cold season, but it increases during warm season. Precipitation presents different influence patterns on Cardiovascular diseases spatially with significant association exists in one area, whereas no association presents in other areas. As for Respiratory diseases, considerable influence is observed from air pollution variables (SO2, Ozone, PM2.5, PM10) and meteorological parameters (Temperature, Relative Humidity, Precipitation). Ozone has a significantly positive influence on Respiratory diseases during the cold season while no significant association exists during the warm season. The same pattern is observed on the influence of Precipitation on Cardiovascular diseases. In conclusion, both meteorological parameters and air pollution have significant effects on ED visits for both Cardiovascular and Respiratory diseases in Coastal Bend, Texas. These findings may have implications for local hospitalization prevention policies.