Discipline: Biological Sciences
Subcategory: Physiology and Health
Room: Marriott Balcony B
Erica M. Molina - Auburn University
Co-Author(s): Mary T. Mendonca
Chronic exposure to low levels of anthropogenic chemicals in the environment continues to be a major health concern. Persistent organic pollutants (POP’s), such as dichlorodiphenyltrichloroethane (DDT), were banned. However, their ubiquitous nature and persistence allows them to remain within the environment at sub-lethal levels for decades. Although levels of POP’s have been decreasing, they are still high enough to potentially affect physiological functions such as oxidative stress and immunological response parameters. We captured two species of small mammals (Peromyscus maniculatus and Sigmodon hispidus) at the Redstone Arsenal, Huntsville, AL, a designated EPA SuperFund site from historically impacted vs. reference areas (S. hispidus: n=12 vs. 6 and P. maniculatus n=13 vs. 19). We collected blood smears and livers to test the hypothesis that chronic exposure to environmental organochlorine contaminants will result in differences in several markers of physiological stress, including 1) different white blood cell distribution. Sex was recorded and body size and weight measurements were taken upon capture. Soil samples collected in 2018 from the DDT abatement area exhibited levels above the Total Threshold Limit Concentration for DDT (i.e. >1ppm), while soil collected contemporaneously from other reference areas did not. Preliminary data was analyzed using ANOVA. There was a significant difference in total WBC counts, with both species (S. h.: 98± 4 vs. 53 ± 40, p= 0.01, P. m.: 86 ± 30 vs. 59 ± 43, p= 0.01) exhibiting lower counts in the impacted vs. the non-impacted area. Similar to total WBC counts, both species exhibited a decrease in lymphocyte count (P. m.: 64 ± 23 vs. 45± 35, p= 0.03, S. h.: 60 ± 7 vs. 31± 26, p= 0.01) and neutrophil count (P. m.: 13± 8 vs. 8 ±7, p= 0.04; S. h.: 31± 5 vs. 16 ± 17, p=0.05) in the impacted compared to the non-impacted area. Our results indicate there may be a problem with the bone marrow and the generation of new leukocytes. The potential for DDT and its derivatives to affect other physiological parameters will be further explored in this study and a subsequent lab study. These studies can provide critical information in what the potential physiological effects of chronic exposure to sub-lethal levels of POPs on humans, as well as wildlife species in the environment. References: Patisaul, H. B., A. C. Gore, and D. Crews. 2017. Environmental Endocrine Disruption of Brain and Behavior.Pages 63–88 in Hormones, Brain and Behavior. Elsevier Shutoh, Y., M. Takeda, R. Ohtsuka, A. Haishima, S. Yamaguchi, H. Fujie, Y. Komatsu, K. Maita, and T. Harada. 2009. Low dose effects of dichlorodiphenyltrichloroethane (DDT) on gene transcription and DNA methylation in the hypothalamus of young male rats: implication of hormesis-like effects. J Toxicol Sci 34:469–482.
Funder Acknowledgement(s): Auburn University Museum of Natural History, NSF-AGEP
Faculty Advisor: Mary T. Mendonca, email@example.com
Role: I did all the research indicated.