However, in real data analysis, there is possibility that a true effect failed to be identified at the initial step given a weak exposure-response association will be missed in the regression model.
In occupational epidemiology, classification of exposure as ever versus never and duration have often been the only available proxies of the actual exposures and are typically cruder and weaker exposure scales than cumulative or intensity-weighted metrics.
We noted a weaker effect of exposure on hospitalization for all respiratory conditions, and no effect on hospitalization for nonrespiratory conditions.
Together, these results suggest that MEHP is a weaker biomarker of exposure to DEHP than the DEHP oxidative metabolites (Koch et al. 2006).
The limited evidence available suggests a more than 2-fold increased risk of Parkinson's disease associated with pesticide exposure and a weaker association with well-water exposure, farming as an occupation, and generally living in a rural setting (82, 85– 85).
Our findings suggested a weaker association with postpregnancy exposure that was essentially null in models that included exposure during all time periods.
However, the interpretation of epidemiological evidence has been complicated by weak exposure assessments and limited case numbers.
Non-existence of the risk, negative confounding, weak exposure or low study-power may explain the negative findings.
Properly conducted, biomonitoring could also help deliver valuable evidence for epidemiologic studies, which are frequently plagued by weak exposure data.
In the NUDATA-study the results on tension neck syndrome were supported by baseline data for neck and shoulder pain symptoms; neck symptoms showed a weaker but still significant exposure-effect relationship to mouse use but not to keyboard use.
It is assumed that this reaction is specific for cells expressing an active cytochrome c oxidase, because strains lacking such an enzyme usually show only a weak reaction upon exposure to TMPD, which can be used as electron donor instead of cytochrome c by terminal oxidases [50].
