118
monsoon it ranged from 108.34 ± 4.17 ppb (at Bagmara) to 159.23 ± 5.17 ppb (at
Kakdwip) whereas, it ranged from 102.86  ±  3.56  ppb (at Bagmara) to
153.23  ±  4.38  ppb (at Kakdwip) during postmosoon. Dissolved Pb values were
found to range from 15.75 ± 2.30 ppb (at Bagmara) to 36.31 ± 3.91 ppb (at Kakdwip)
in premonsoon; in monsoon it ranged from 24.45  ±  3.11  ppb (at Bagmara) to
44.14 ± 2.38 ppb (at Kakdwip) and in postmonsoon it ranged from 19.45 ± 2.38 ppb
(at Bagmara) to 41.45  ±  2.45  ppb (at Kakdwip) in the year 2013. Dissolved Hg
values were found to range from 0.28 ± 0.05 ppb (at Bagmara) to 0.54 ± 0.02 ppb
(at Kakdwip) in premonsoon; in monsoon it ranged from 0.32  ±  0.01  ppb (at
Bagmara) to 0.63  ±  0.01  ppb (at Kakdwip) and in postmonsoon it ranged from
0.30 ± 0.07 ppb (at Bagmara) to 0.58 ± 0.05 ppb (at Kakdwip) in the year 2013.
Fig. 5.2 Scientific name: Avicennia alba; Local name: Kalo Baen
Fig. 5.3 Scientific name: Avicennia officinalis; Local name: Sada baen
5 Mangroves: A Sink of Heavy Metals