We show how spending different amount of time outdoors on weekends and weekdays changes the estimates of the impact of ground level ozone on respiratory diseases and Asthma. Our focus is on the short term effect of air pollution on public health. The American Time Use Survey data are used for...

In this paper, we present a new time series model, whichdescribes self-exciting threshold autoregressive (SETAR) nonlinearityand seasonality simultaneously. The model is termed multiplicativeseasonal SETAR (SEASETAR). It can be viewed as a special case of ageneral non-multiplicativeSETAR model...

Time series regression models are especially suitable in epidemiology for evaluating short-term effects of time-varying exposures on health. The problem is that potential for confounding in time series regression is very high. Thus, it is important that trend and seasonality are properly...

Recent research suggests that short-term exposure to air pollution is associated with an elevated prevalence of respiratory infectious disease. We examine the relationship between the air quality index (AQI) and weekly cases of influenza-like illnesses (ILI) and COVID-19 in the United States. We...

Recent research suggests that short-term exposure to air pollution is associated with an elevated prevalence of respiratory infectious disease. We examine the relationship between the air quality index (AQI) and weekly cases of influenza-like illnesses (ILI) and COVID-19 in the United States. We...

This paper discusses identification, specification, estimation and forecasting for a general class of periodic unobserved components time series models with stochastic trend, seasonal and cycle components. Convenient state space formulations are introduced for exact maximum likelihood...

Safe and adequate water supply is a vital element to preserve human health; however, access to clean water is limited in many developing countries. Furthermore, improved water sources are often contaminated with fecal matters and consumption of unsafe water poses a great public health risk. This...