Elemental mercury contamination survey in a chlor-alkali plant by the use of transplanted Spanish moss, Tillandsia usneoides (L.)

Atmospheric Hg0 contamination and the potential risk of occupational exposure were evaluated in a chlor-alkali facility by the use of transplanted Tillandsia usneoides. This plant species was selected since it presents some features that makes it useful for air monitoring purposes. After short-term exposure (15 days), control plants showed a mean concentration of 0.2 μg Hg.g−1 whereas Hg values in transplants ranged from 1 to 10 400 μg.g−1. This latter value was observed near an elemental Hg spillage. Even after exposure to toxic conditions plant metabolism was still operative, allowing the transplant technique to be employed to assess both Hg taken up through the stomata and Hg associated with particles deposited on the biomonitor.