AIC's 52nd Annual Meeting

In the spring of 2023, conservators at The Metropolitan Museum of Art began assessing the condition of objects in the Modern and Contemporary Art collection to prepare to move the collection offsite during the renovation of these galleries. As part of this assessment, several radioactive glass and ceramic objects (including four from the popular Fiestaware brand) were initially identified using a Geiger counter, then analyzed via pXRF to confirm the presence of uranium. In preparation for packing, Met conservators sought to develop a storage solution that would mitigate health risks to museum professionals working with radioactive objects.

Objects containing uranium emit alpha, beta, and gamma radiation. While alpha and beta radiation have the greatest ability to damage living tissue, gamma radiation is generally considered more concerning for professionals working with uranium-containing ceramics and glass because alpha and beta particles are unable to travel far from their sources and can be blocked by relatively light materials. Studies have found the risks of handling uranium-containing ceramics and glass to be minimal when reasonable precautions are taken. However, in the event of damage to a radioactive object, prolonged close contact with fragments caught in the folds of clothing or a particle inhaled into the lungs could have serious health effects through direct exposure to alpha and beta radiation. In addition to these risks, uranium also generates radon gas as it decays. Radon is carcinogenic and the second leading cause of lung cancer, after smoking.

Institutions concerned with the containment of particles shed by radioactive objects have come to diverging solutions. Sealing objects in polyethylene zip top bags effectively prevents particulate contamination but also traps radon gas generated by the objects, necessitating the opening of the bags in a well-ventilated space. Housing radioactive objects in open boxes or trays prevents radon buildup but may not adequately address the problem of containing particles should the object be damaged.

The authors devised an elegant solution that addresses both problems by creating enclosures using a combination of soft Tyvek® (grade 14-M) and polyethylene zip top bags. Experiments on barrier materials for radon detectors by members of the American Association of Radon Scientists and Technologists have demonstrated that Tyvek® allows nearly 100% radon transmission. As a polyethylene material, Tyvek® is easily joined to components from polyethylene bags using a heat sealer. The custom pouches made from Tyvek® and zip top bags are designed to contain fragments generated by damage to the object inside while still allowing the venting of radon gas. They are resealable and provide a clear window through which the object can be viewed. Beyond radioactive objects, the pouches have the potential to be used in any situation where the creation of a microclimate in a sealed bag is undesirable. This poster will detail the factors considered in developing the pouches and include product samples to share with interested colleagues.