A pooled-analysis by Lanphear et al. (2005) of seven cohort studies of the association between blood lead (BPb) concentrations in children and measures of their intelligence concluded that "environmental lead exposure in children who have maximal blood lead levels <7.5 μg/dL is associated with intellectual deficits.
View Article and Find Full Text PDFBoth classical and Berkson exposure measurement errors as encountered in environmental epidemiology data can result in biases in fitted exposure-response relationships that are large enough to affect the interpretation and use of the apparent exposure-response shapes in risk assessment applications. A variety of sources of potential measurement error exist in the process of estimating individual exposures to environmental contaminants, and the authors review the evaluation in the literature of the magnitudes and patterns of exposure measurement errors that prevail in actual practice. It is well known among statisticians that random errors in the values of independent variables (such as exposure in exposure-response curves) may tend to bias regression results.
View Article and Find Full Text PDFThe effects of 0.1 to 0.6 ppm nitrogen dioxide (NO2) on airway hyper-responsiveness (AHR) to airway challenges in asthmatics have been evaluated in several controlled exposure studies.
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