Bioaccumulation potential of chlorpyrifos in resistant Hyalella azteca: Implications for evolutionary toxicology

Nadhirah Johanif; Kara E Huff Hartz; Alexandra E Figueroa; Donald P Weston; Devon Lee; Michael J Lydy; Richard E Connon; Helen C Poynton

doi:10.1016/j.envpol.2021.117900

Bioaccumulation potential of chlorpyrifos in resistant Hyalella azteca: Implications for evolutionary toxicology

Environ Pollut. 2021 Nov 15:289:117900. doi: 10.1016/j.envpol.2021.117900. Epub 2021 Aug 2.

Authors

Nadhirah Johanif¹, Kara E Huff Hartz², Alexandra E Figueroa¹, Donald P Weston³, Devon Lee⁴, Michael J Lydy², Richard E Connon⁵, Helen C Poynton⁶

Affiliations

¹ School for the Environment, University of Massachusetts Boston, Boston, MA, 02125, USA.
² Center for Fisheries, Aquaculture and Aquatic Sciences, and Department of Zoology, Southern Illinois University, Carbondale, IL, 62901, USA.
³ Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA.
⁴ Department of Biochemistry, California State University, Fresno, CA, 93740, USA.
⁵ School of Veterinary Medicine, Department of Anatomy, Physiology, and Cell Biology, University of California, Davis, CA, 95616, USA.
⁶ School for the Environment, University of Massachusetts Boston, Boston, MA, 02125, USA. Electronic address: helen.poynton@umb.edu.

PMID: 34391048
DOI: 10.1016/j.envpol.2021.117900

Abstract

Given extensive use of pesticides in agriculture, there is concern for unintended consequences to non-target species. The non-target freshwater amphipod, Hyalella azteca has been found to show resistance to the organophosphate (OP) pesticide, chlorpyrifos, resulting from an amino acid substitution in acetylcholinesterase (AChE), suggesting a selective pressure of unintended pesticide exposure. Since resistant organisms can survive in contaminated habitats, there is potential for them to accumulate higher concentrations of insecticides, increasing the risk for trophic transfer. In the present study, we estimated the uptake and elimination of chlorpyrifos in non-resistant US Lab, and resistant Ulatis Creek (ULC Resistant), H. azteca populations by conducting 24-h uptake and 48-h elimination toxicokinetic experiments with ¹⁴C-chlorpyrifos. Our results indicated that non-resistant H. azteca had a larger uptake clearance coefficient (1467 mL g^-1 h^-1) than resistant animals (557 mL g^-1 h^-1). The half-life derived from the toxicokinetic models also estimated that steady state conditions were reached at 13.5 and 32.5 h for US Lab and ULC, respectively. Bioaccumulation was compared between non-resistant and resistant H. azteca by exposing animals to six different environmentally relevant concentrations for 28 h. Detection of chlorpyrifos in animal tissues indicated that resistant animals exposed to high concentrations of chlorpyrifos were capable of accumulating the insecticide up to 10-fold higher compared to non-resistant animals. Metabolite analysis from the 28-h concentration experiments showed that between 20 and 50 % parent compound was detected in H. azteca. These results imply that bioaccumulation potential can be more significant in chlorpyrifos resistant H. azteca and may be an essential factor in assessing the full impacts of toxicants on critical food webs, especially in the face of increasing pesticide and chemical runoff.

Keywords: Bioaccumulation; Hyalella azteca; Non-target; Organophosphate; Pesticide resistance.

MeSH terms

Acetylcholinesterase / metabolism
Amphipoda* / metabolism
Animals
Bioaccumulation
Chlorpyrifos* / toxicity
Insecticides* / analysis
Insecticides* / toxicity
Water Pollutants, Chemical* / analysis
Water Pollutants, Chemical* / toxicity

Substances

Insecticides
Water Pollutants, Chemical
Acetylcholinesterase
Chlorpyrifos