Estimating human indoor exposure to elemental mercury from broken compact fluorescent lamps (CFLs).

UNLABELLED: The 2008 EU regulation, which prohibits conventional incandescent light bulbs, is to be implemented in phases, completing in 2012. One of the possible substitutes is the compact fluorescent lamp (CFL), which, however, does contain up to 5 mg of mercury in its elemental or amalgamated form. The question arises as to the possible exposure of individuals to mercury as a result of lamp breakage during operation or when disconnected from the power supply. Therefore, an apparatus was built to shatter CFLs and drop the shards onto glycol-modified polyethylene terephthalate, a carpeted floor, or laminate floor under defined climatic parameters and operating conditions. Six CFLs of different types and mercury content were studied. After the breakage of a common CFL containing liquid mercury, concentrations up to 8000 ng/m(3) were reached in the chamber. Much lower peak values were obtained with amalgam-type lamps (414 ng/m(3)) or with lamps with a shatter-proof coating (60 ng/m(3)). It was found that ventilation can considerably reduce the indoor air concentration within 20 min. Acute health effects would only be expected if the mercury is not removed immediately. Careful collection and disposal of the lamp fragments would also prevent dwellers from the risk of long-term exposure.

PRACTICAL IMPLICATIONS: After accidental breakage of a compact fluorescent lamp (CFL) indoors, dwellers could be exposed to high mercury concentrations. From the results of our studies in test chambers and real rooms using different lamp types and scenarios, it was possible to estimate the possible human uptake of mercury by inhalation. Immediate action is important to reduce indoor mercury concentrations to a minimum level. The first step is to maximize ventilation followed by careful collection of spilled mercury.