Abstract

Dried blood spot cards represent a new tool in wildlife toxicology to efficiently collect, transport, and archive blood samples for persistent organic pollutant (POP) analysis. This would greatly benefit future wildlife health assessments, where the collection of large volumes of blood for POP analysis is often limited by animal body size and safety, practicality, and storage/transport. It is important to measure POPs as they have been implicated as a co-factor in numerous viral-induced mass mortality events affecting hundreds to thousands of individual marine mammals. In a preliminary study using dried blood spot cards, grey seal (Halichoerus grypus) pups positive for influenza A virus (IAV) had significantly higher concentrations of total polychlorinated biphenyls (PCB) compared to PCB concentrations in IAV negative animals. These data suggested a potential relationship between pollutants and IAV in grey seal pups. However, there is a critical need to validate whether the POP measurements using dried blood spot cards are accurate, both for the breadth of POPs measured, as well as their concentrations, when compared to whole blood measurements. The following hypothesis was tested, “Profiles and concentrations of persistent organic pollutants are not significantly different between dried blood spot cards and whole blood in grey seal pups,” by identifying, quantifying and comparing blood POPs between dried blood spot cards and whole blood. During the January–February 2017 grey seal pup health assessment field season on Muskeget and Monomoy Islands, Cape Cod, MA, dried blood spot cards and whole blood were collected and archived from n=30 grey seal pups. From both dried blood spot cards and whole blood, a suite of individual PCB congeners and organochlorine pesticides were measured using the Agilent 6890 GC with a Waters Tandem Mass Spectrometer (GC/MS/MS). A Fisher’s exact test was used to compare the frequency distribution (i.e., contingency table) between blood spot cards and whole blood. There were no significant differences in the proportion of observations, which defined the contingency tables. Therefore, the blood spot cards detected the same POPs, as well as similar concentrations, when compared to whole blood, thus validating the use of blood spot cards. In the future, dried spot cards may be incorporated into wildlife health assessments, as well as in the health assessment of stranded marine mammals under care at zoo and aquarium rehabilitation facilities.

Acknowledgements

This work was supported by a 2017–2018 American Association of Zoo Veterinarian Wild Animal Health Fund grant to Milton Levin.

*Presenting author