Australian standards mandate that compact fluorescents CFLs contain no more than 5mg of mercury and a fluorescent tube cannot contain more than 15mg.
The risk of mercury poisoning even when a CFL or fluorescent tube is broken indoors is extremely low.
It is the accumulation of mercury in landfill across Australia that is a cause for concern across the wider environment. Currently it is estimated that 95% of mercury-containing lamps are sent to landfill in Australia.
Mercury in landfill converts to the toxic methylmercury and spreads through the wider environment through air, water and soil.