Changes in persistent organic pollutant levels from adolescence to young adulthood

Abstract

Elimination rates and their corresponding half-lives are conceptually important and intuitively accessible pharmacokinetic measures of toxicant elimination, but regression-based estimates are biased proportional to the degree of continuing (background) exposure. We propose an alternative estimator, the censored normal regression model, which uses all observations, but treats individuals whose initial level failed to exceed their follow-up level as censored observations to weight the regression estimates from those that declined between blood draws. In this manner, we derive the intrinsic elimination rate, the elimination rate free from ongoing exposure, as a parameter in a regression with an unobserved, latent dependent variable. We utilize sequential measurements of persistent organic pollutants (POPs) levels from adolescence to adulthood, a period of intense change in size and body composition, to quantify individual-level change within a community exposed to significant quantities of contaminants over an extended period of time. Although much research has been conducted on effects of POPs, far less attention has been given to vectors of intake and changes in toxicant levels during the life course. We apply exploratory factor analysis (EFA) to types and timing of consumption, along with physical behavioral characteristics, to identify a structure of seven underlying factors. Although several variables show factorial complexity, the latent constructs included an age/maturation and period-related factor, a nutritional composite, consumption prior to pregnancy, fish and fowl consumed during pregnancy, factors distinguishing body mass and weight from height, and bottom-feeding fish consumption. Unadjusted and adjusted half-lives using the censored normal regression estimator, as well as estimated half-lives from conventional log concentration regressions, are reported for PCB groupings, specific congeners, p,p′-DDE, and HCB.

PCBs and measures of attention and impulsivity on a continuous performance task of young adults

“…By venipuncture, 20 mL of blood were collected for PCBs analysis and the samples were periodically transferred to the University at Albany's Exposure Assessment Laboratory for analysis. Detailed descriptions of venipuncture and analytic procedures are given in previous publications (DeCaprio et al, 2000, 2005; Gallo et al, 2015; Schell & Gallo, 2010; Schell et al, 2003, 2009). …”

Comparison of Organochlorine Pesticide Levels Between Human Blood Serum and Adipose Tissue

“…The quantification of individual levels within inhabitants exposed to the contaminants over an extended life span was measured by sequential determinations of these pesticides (Herrero et al 2011, Waliszewski et al 2012, Caba et al 2015, Gallo et al 2015. Therefore, the organochlorine pesticide residues draw attention to many problems related to human pollution, originated by life in a polluted environment.…”

Persistent Organic Pollutant Exposure and Thyroid Function among 12-Year-Old Children

“…The blood samples collected in our study when children were 12 years old reflect chronic exposure to POPs. Gallo et al [49] estimated that the half-lives of PCB 118, 138, and 153 range between 3 and 22 years, p,p’-DDE between 7 and 35 years, and HCB between 9 and 70 years. Median concentrations of PCBs were lower in our study than those described by Osius et al in 1999 [16] and Schell et al in 2008 [50]; yet were similar to those reported by Bandow et al [51] in Germany for children aged 3–17 years between 2014 and 2017 (PCB 138: 0.02 µg/L, PCB 153: 0.07 µg/L; and PCB 180: 0.03 µg/L).…”