Pesticide contamination of objects repatriated under the native American graves protection and repatriation act: A multi-disciplinary approach

The Native American Graves Protection and Repatriation Act (NAGPRA) of 1990 provided for the return of human remains, funerary objects, sacred objects, and objects of cultural patrimony, from museums, universities, and federal agencies to Native American Tribes. As a routine part of preservation, many objects were treated with pesticides, including compounds of arsenic and mercury. Curatorial records are seldom complete. There is a potential for human exposures, particularly with transfer to non-museum settings or in return to cultural use. Four objects eligible for repatriation were evaluated by a team consisting of a museum conservator, an analytic chemist, a medical toxicologist, and tribal representatives. The following were addressed: 1) Object construction and collection history; 2) Quantitative determination of residues detectable by X-ray fluorescence spectroscopy (XRF); 3) Past, current and future object storage, handling, and use; 4) Exposure risk assessment and development of storage, handling, and use guidelines; 5) Communication of findings; and 6) Tribal concerns. A headdress (rows of upright hair on a leather base), two medicine bags (otter skins with textile and metal attachments), and a leather shirt (semi-tanned buckskin and glass beads) were evaluated. XRF detected As, Cr, Fe, Hg, Pb, Rb, Sr, and Zr in the objects or attachments. One of four objects tested had high levels of arsenic and lead, without indications of prior pesticide treatment. This object poses significant potential health risks. Other metals detected were likely related to leather tanning, or in glass or metal attachments, and pose minimal health risks. A multi-disciplinary approach allowed a more comprehensive assessment of object history, pesticide contamination, tribal capabilities, the potential for human exposures, and in education efforts.