Removing External Contamination in Wildlife Tissues Before Analyses

Birds and bats can be exposed to environmental toxins including mercury, arsenic, lead, and zinc through water, food, and air pollution.

While non-invasive measurements of these substances have been useful in supporting estimates of overall contaminant exposure, it is crucial to first eliminate potential external toxins from the test subject — contamination that may occur in dust or dirt or through wildlife preservation processes — to ensure accurate measurements.

In their research article, titled "Evaluating washing techniques to eliminate external contamination of trace elements in bat fur and bird feathers," published in the journal Ecotoxicology and Environmental Safety, Exponent scientist Beatrice Hernout and co-authors from academia explore various approaches to removing these external contamination sources without skewing toxicity measurements.

Research findings and implications

Through research involving fur samples of great flying foxes — a bat species found in New Guinea and in the Bismarck Archipelago — and feather samples of the great horned owl and the great blue heron from museum collections, the authors of the article determined the application of acetone and detergent to be effective for external metal removal.

Metals and metalloids, substances with both metal and non-metal properties such as mercury and arsenic, have been found to have wide-reaching health impacts to wildlife, including bats and birds, when exposed to high levels.

For bats, metal and metalloid exposure may result in death or DNA damage and may otherwise impact the abundance of bats within a region or ecosystem. Avian health has also been found to be negatively impacted by high exposure levels to metals, leading to organ failure and neurological, reproductive, cell development, and behavioral disorders.

"In light of an increasing number of studies using non-invasive techniques to monitor pollutant levels in birds and mammals," write the authors, "our study will improve the consistency and comparability of future studies in wildlife toxicology."

From the publication: "The use of washing reagents on these matrices prior to metal analyses remains metal-dependent, and we recommend researchers to potentially test washing techniques on their sample matrices for selected contaminant(s) before analysis."