Chronic Exposure to Environmental DDT/DDE in 2 Species of Small Rodents: Measures of Contaminant Load, Immune Dysfunction, and Oxidative Stress

Abstract

Persistent contaminants are ubiquitous in our water and soil, and thus chronic exposure to environmentally relevant levels of these contaminants may pose a risk to humans and wildlife. Two species of small mammals (deer mouse, Peromyscus maniculatus and cotton rat, Sigmodon hispidus) were collected from historically dichlorodiphenyltrichloroethane (DDT)-contaminated and reference areas at the Redstone Arsenal (Huntsville, AL, USA), a US Environmental Protection Agency (USEPA)-designated Superfund site. Soil samples taken concurrently with mammal collection from the DDT abatement site exhibited DDT and dichlorodiphenyldichloroethylene (DDE) levels >1 ppm (USEPA total threshold limit concentration for DDT and DDE <1 ppm), whereas soil samples from the reference area had undetectable levels. Liver samples from individuals of both species collected in the contaminated areas also had significantly elevated DDT/DDE levels, with P. maniculatus averaging an approximately 20× greater load than that documented for S. hispidus. Both rodent species collected from the contaminated site had significantly lower total leukocyte counts and total differential blood cell counts (p = 0.01 and p = 0.04, respectively) than those collected from the nearby (~7000-m) reference site. Cellular stress indices also trended higher in both species, suggesting a potential for chronic exposure to DDT to act as a mediator of oxidative damage. The present study provides support to the idea that environmental exposure to low levels of contaminants can cause physiological consequences that may influence immune responsiveness and initiate cellular stress in resident mammals.

Exposure to Persistent Organic Pollutants in Australian Waterbirds

“…One exception was the congener PCB‐156, which suggests there may be a local, legacy source of PCBs to the environment in Victoria, which requires further investigation. Generally, OCPs had a low detection rate, but DDE exposure was still relatively high and consistent with worldwide literature, indicating that DDT breakdown products are still a global issue (Molina et al, 2021). In addition, there has been recent discussion of the dangerous nature of ongoing poorly related use of pesticides in Australia (Schneider, 2021).…”

Seguridad y satisfacción de fumigadores para el control de enfermedades transmitidas por vectores en Arequipa

“…Es importante resaltar que la exposición prolongada a insecticidas puede ser perjudicial para la salud, teniendo en cuenta que dentro de la población del estudio la mayoría tenias más de 10 años de ambigüedad. Estudios recientes indicaron que la exposición crónica a niveles ambientales relevantes puede representar un riesgo para los humanos y la vida silvestre, provocando disfunción inmunitaria y estrés oxidativo (Molina et al, 2021). Así mismo, Moura et al, (2020) en una investigación de revisión bibliográfica encontraron tres casos de neoplasias hematológicas asociadas a la exposición por malatión, en discrepancia con Hu et al, (2017) quienes no encontraron relación estadísticamente significativa en asociación con linfoma no Hodgkin.…”

Effects of chronic dichlorodiphenyldichloroethylene exposure on testosterone secretion and steroidogenic pathway in the male gonad

“…In addition, Blanco-Munoz et al [7] documented effects of chronic DDT exposure in humans at the gonadal, pituitary, and hypothalamic levels, indicating that the mechanisms by which DDT causes its effects are still unclear and require further study. To explore the potential mechanisms of action seen in our previous field and lab studies [8], we exposed male rats to environmentally relevant DDE doses extrapolated from our field study [9]. We found that DDE exposure of prepubertal (21–35 days of age) and pubertal rats (35–49 days of age) caused animals at both age groups to exhibit decreased serum T and testicular T production in a nonmonotonic dose–response that has been reported for many endocrine disruptors [9, 10].…”