January 25, 2021

Advancing the science in toxicology

In a recently published paper, Ramboll experts Cynthia Van Landingham, William G. Fuller and Rosalind A. Schoof examine lead exposure and IQ .

The journal Critical Reviews in Toxicology recently published an important paper by Ramboll Health Sciences experts Cynthia Van Landingham, William G. Fuller and Rosalind A. Schoof.
The paper, The effect of confounding variables in studies of lead exposure and IQ, uses epidemiological data (based on data reported by Lanphear et al. 2005 and Crump et al. 2013) to explore the limitations of current regression models in extrapolation to the low dose region of the dose-response curve due to the existence of unrecognized and uncontrolled confounding. A confounding variable is an unmeasured third variable that influences both the supposed cause and the supposed effect.
According to Harvey Clewell, PhD, a senior expert in Ramboll who reviewed the paper, “This is a very important study with serious implications for estimating low-dose risk from epidemiological data. It clearly demonstrates that when analyses of epidemiological studies do not adequately account for possible confounding by underlying associations, the likelihood of low-dose effects can be seriously mis-represented. It should be taken as a warning by epidemiologists and risk assessors.” Dr. Clewell has authored more than 200 peer-reviewed scientific publications and book chapters and is currently a member of the USEPA Scientific Advisory Board’s Chemical Assessment Advisory Committee.
Critical Reviews in Toxicology publishes research on toxicology and the application of toxicological information to assess human health hazards and risks.