Recent reports discuss the clear need for developing improved measures of environmental exposures, and lay out details of next steps in this area [National Research Council [2012; Balshaw and Kwok 2012]. Although these advances will reduce environmental measurement error and improve tests of GxE, some participants noted that it typically will not be feasible to remove all error. More accurate environmental exposure methods may not be applicable in some current large population-based studies because the data and specimens were already collected, because of expense of these measures, or because of other factors.
