Portable X-ray fluorescence for identifying harmful lead exposure in wild mammals through hair analysis

Lead exposure threatens scavenging wildlife globally. For inexpensive estimation of lead concentration in bones from avian scavengers, portable X-ray fluorescence (XRF) devices have been trialed. However, portable XRF has not been validated for tissue lead measurement in non-human mammalian scavengers. We evaluated portable XRF for hair lead measurement in the endangered Tasmanian devil (Sarcophilus harrisii). We first analyzed large ([~]1.0 g) hair samples from 39 deceased animals from southeastern Tasmania via portable XRF and then inductively-coupled plasma mass spectrometry (ICP-MS) (validation study). We then measured lead concentrations via portable XRF only in 61 small ([~]0.1 g) hair samples from live devils from a plantation landscape (plantation study). Portable XRF measures of hair lead levels were positively correlated with ICP-MS values (R2 = 0.61). In the validation study, 95% of sampled Tasmanian devils had relatively low lead levels (< 2 mg/kg), but the remaining two showed elevated lead levels (> 15 mg/kg). Mean lead levels in the plantation study and validation study were not significantly different. Our preliminary results suggest that portable XRF can provide a useful measure of differences in lead levels in wildife hair over a coarse scale. We provide recommendations for further research and refinement of this method. SynopsisPortable XRF can provide inexpensive and non-destructive analysis of environmental contaminants in wildlife. We present the first evaluation of portable XRF for analysis of lead contamination in mammalian scavenger hair.