The mercury burden in waste water released from dental clinics.
The aim of this study was to estimate mercury burden in waste water samples collected during one working day in 27 dental clinics. The samples were subjected to authorized analysis using the technique of QS-IE Enhanced Cold Vapour Mercury Analyzer to estimate the amount of mercury discharged. The mean value of mercury discharged was 2.49 parts per billion (ppb) for the clinics equipped with amalgam separators and 94.75 ppb for the clinics without amalgam separators. Some of the small amalgam particles released when new fillings are placed or during removal of old restorations form a sediment in tubes and drains. The remaining particles are carried with the waste water stream to the local purifying plant. If threshold values for heavy metal content including mercury are exceeded, the sludge is not allowed to be recycled as fertiliser. Installation of an approved amalgam-separating apparatus in dental clinics is recommended so as to reduce considerably the discharge of mercury into waste water.
al-Shraideh
M
M
Department of Allied Dental Sciences, Jordan University of Science and Technology, PO Box 3030, Irbid-Jordan.
al-Wahadni
A
A
Khasawneh
S
S
al-Shraideh
M J
MJ
D003740:Dental Clinics; D003748:Dental Equipment; D018057:Dental Waste / Q000032:analysis*; D006801:Humans; D007597:Jordan; D008628:Mercury / Q000032:analysis*; D012722:Sewage / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000295:instrumentation; D014881:Water Supply
D018057:Dental Waste; D012722:Sewage; D014874:Water Pollutants, Chemical; D008628:Mercury