As they age, tritium EXIT signs become less effective and more toxic, as the tritium gas inside them is converted to the more toxic oxide form. One sign, thrown into a landfill can create significant groundwater pollution.
Various American authorities have recently posted detailed information on the internet about responsible management of tritium EXIT signs. Authorities in the United States appear to be way ahead of their Canadian counterparts in addressing the serious problems created by use and disposal of these signs, many of which are manufactured in Canada.
In the U.S., the Department of Defense, National Institutes of Health and Environmental Protection Agency all have prohibited use of tritium signs. Here are two informative web resources created recently by American authorities.
1) Responsible Management of tritium EXIT signs - excellent on-line training module from the Environmental Protection Agency that includes information on health risks, a key to identify tritium signs, recommended alternatives, and safe procedures for disposal.
2) Bureau of Radiation Protection, State of Pennsylvania - detailed webpage with much information about the problems with tritium exit signs.
TAP asks “Where is Canada’s information on responsibly dealing with tritium exit signs”?
There are many problems with tritium exit signs, as detailed in the TAP fact sheet on this topic.
Disposal of waste exit signs can seriously pollute groundwater. Tritium lights become much more hazardous to the environment as they age; the glass tubes act as sponges for tritium, converting it into its more hazardous and soluble oxidized form. Information linking high levels of tritium oxide in landfill leachate to discarded exit signs, has recently come to light in Scotland, South Africa, Italy and several states in the U.S. Regulators are grappling with the issue of how to ensure that used tritium exit signs go to monitored, radioactive waste storage facilities (1,2). Although no Canadian data are available, the situation may be worse here because regulations allow for disposal of used exit signs in ordinary landfills.
References:
1) Study of tritium in leachate from Scottish landfill sites
2) State of Pennsylvania Department of Environmental Protection
MARTIN MITTELSTAEDT, ENVIRONMENT REPORTER, The Globe and Mail
Wednesday, December 26, 2007
The Ministry of Environment has found elevated levels of radioactive tritium in ground water at the municipal dump serving Pembroke, Ont., and several other nearby Ottawa River valley communities.
The dump, the Alice and Fraser Township Landfill, is not licensed to receive radioactive waste, and it is not known exactly how tritium, used to make glow-in-the-dark lights, among other products, and nuclear weapons, got into the dump. Read more…