No. 104 - Miljøstyrelsen

58
Evaporation of mercury will take place as long as there are still mercury
residues present in the room.
For prolonged exposure to mercury in a home it has not been possible within
the frames of the present project to make a calculation of the concentrations
of mercury in a home since it depends on many factors such as ventilation,
level of cleaning etc. Therefore, a DNEL long value has been compared with
concentrations of mercury vapour measured in tests conducted after cleaning
of broken fluorescent lamps. These concentrations derive from various tests
found in a literature study.
Literature describes that it has been demonstrated in practical tests that a
cleaned-up home after breakage of a fluorescent lamp can still release mercury
vapours for several weeks/months after the accident. In some cases it took
several weeks before measured values just above floor height were below
DNEL long value. Thereby crawling children may be exposed to concentrations
with health-hazardous effects in the long-term perspective. In connection with
general cleaning/vacuuming in a home mercury-containing dust may be
stirred up.
Thus, the conclusion regarding exposure to mercury vapours in the long term
is that there may be a risk of health effects in case ventilation and removal of
all mercury-containing residues (i.e. thorough cleaning) is not ensured.
Thorough cleaning after breakage of the lamp is thus important and so is
ventilation for a long period, since mercury vapours may be released from
invisible residues of the broken lamp.