For each individual there are two measures of each normalized phenotype: one reflecting levels pre-statin exposure (baseline, X), and one reflecting levels post-exposure (on study, Y).
Although oesophageal pH monitoring shows considerable intra-individual day-to-day variability, systematic order effects with lower acid exposures on Study Day 2 are not found.
The ESCAPE project has reported significant associations of long-term air pollution effects with acute coronary events, lung cancer, and mortality by harmonizing air pollution exposures on study subjects across European cohorts (Beelen et al. 2014; Cesaroni et al. 2014; Raaschou-Nielsen et al. 2013).
The questionnaires elicited information on exposure to study waters and the presence of specific symptoms in a defined period prior to receiving the form.
Descriptive and ecologic studies provide no information on specific exposures of study subjects; rather, they use population levels as surrogates for individual exposure.
Heat index was calculated to measure the effects of heat exposure on the study population, which consisted of 21 workers at five worksites; a questionnaire was also used to collect data on workers.
We found little to no evidence of effects of low-level mercury exposure on other studied anthropometric measures at birth.
In addition, we used a Monte Carlo sensitivity analysis to assess the potential effects of exposure measurement errors on study estimates.
There is increasing awareness of the importance to incorporate information on noise exposure in studies on traffic-related air pollution exposure and health [ 10- 13].
We also did not evaluate the potential effects of environmental factors (e.g., ambient pollution, traffic, noise) before the controlled exposures or during the 2-hr period after the randomized exposures on our study end points.
Ten studies relied on one variable to measure occupational exposure, while 26 studies report on 2 to 4 variables and the 9 remaining studies assessed five or more.
