Lagging exposure information is often undertaken to allow for a latency period in cumulative exposure-disease analyses. The authors first consider bias and confidence interval coverage when using the standard approaches of fitting models under several lag assumptions and selecting the lag that maximizes either the effect estimate or model goodness of fit. Next, they consider bias that occurs wh...

OBJECTIVES To evaluate the current evidence that cumulative exposure to inorganic lead is associated with decreased performance in neurobehavioural tests in adults. METHODS 21 unique studies were reviewed from 28 published manuscripts. An algorithm was developed to determine the usefulness of each study on the basis of exposure assessment, control of confounding variables, methods of subject ...

Cumulative exposure to ultraviolet radiation (UVR) increases the risk of developing skin cancer, particularly squamous cell carcinoma and basal cell carcinoma. Thus, the need for protection from the sun is widely advocated, but consumers generally associate such protection with the occasional extreme exposure and tend to ignore the risk of long-term exposure. In fact, a sun exposure model predi...

Exposure to air pollution during pregnancy has been suggested to be a risk factor for preterm birth; however, epidemiologic evidence remains mixed and limited. The authors examined the association between ambient levels of particulate matter <2.5 μm in aerodynamic diameter (PM(2.5)) and the risk of preterm birth in North Carolina during the period 2001-2005. They estimated the risks of cumulati...