Use of Mercury in Dental Silver Amalgam: An Occupational and Environmental Assessment
Table 4
Mean mercury concentration (mg/L) in wastewater of dental clinics, from Lahore.
Collection site
Number of chairs
Mean Hg
Mean Hg
Clinic A
2
183.0 (±20.7)
237.0 (±33.2)
Clinic B
3
221.7 (±71.7)
264.0 (±22.3)
Clinic C
2
248.3 (±32.2)
279.4 (±76.8)
Clinic D
1
257.0 (±36.1)
299.7 (±32.2)
Clinic E
3
261.0 (±83.4)
313.7 (±19.7)
Clinic F
2
107.0 (±47.9)
161.5 (±36.1)
Clinic G
2
162.7 (±51.8)
259.0 (±65.5)
Clinic H
2
137.3 (±35.6)
211.3 (±15.7)
Clinic I
1
115.7 (±16.8)
186.3 (±29.5)
Clinic J
2
162.0 (±20.7)
237.0 (±25.7)
Clinic K
2
86.7 (±56.3)
112.0 (±23.2)
Clinic L
2
179.0 (±62.2)
251.7 (±42.6)
Clinic M
2
156.3 (±88.3)
278.0 (±9.71)
Clinic N
1
164.3 (±49.7)
197.3 (±12.0)
Clinic O
2
212.7 (±7.02)
343.3 (±45.7)
Clinic P
2
169.0 (±13.0)
242.7 (±29.5)
Clinic Q
2
247.0 (±15.5)
295.0 (±11.1)
Clinic R
3
126.0 (±67.6)
263.7 (±19.8)
Clinic S
2
170.7 (±44.6)
253.3 (±44.5)
Clinic T
2
101.7 (±82.1)
218.3 (±17.9)
Clinic U
2
251.7 (±56.2)
318.0 (±25.3)
Clinic V
1
91.3 (±42.8)
143.0 (±23.2)
Mean
1.95
173.3
243.9
SD
0.57
56.54
58.23
Each value is the mean of three replicates; the standard deviation of three replicates is presented in parentheses. Samples collected from discharge point into wastewater collection system. Samples collected from the side-holding tank of dental chairs.
