Kwokal Z, Sarkar S K, Chatterjee M, Franciskovis-Bilinski S, Bilinski H, Bhattacharya A, Bhattacharya B D, Alam Md Aftab
Centre for Marine and Environmental Research, Rudjer Boskovic Institute, P.O. Box 180, 10001 Zagreb, Croatia.
Bull Environ Contam Toxicol. 2008 Jul;81(1):105-12. doi: 10.1007/s00128-008-9443-4. Epub 2008 May 28.
This is a preliminary report on total mercury (T(Hg)) in core sediments (<63 microm particle size) of Sunderban mangrove wetland, northeastern part of the Bay of Bengal, India. Cold vapor atomic absorption spectrometry (CVAAS) was used for T(Hg) determination. The concentration varies from 9.8 to 535.1 ppb (ngg(-1)). Results revealed variations over premonsoon and postmonsoon month at different core depth, as well as in studied three sampling stations, located at the site of three rivers: Hugli River (S(1)), Matla River (S(2)) and Bidyadhari River (S(3)). Elevated concentration of T(Hg) in subsurface layer (4-8 cm) of the core at S(2) is attributed to remobilization of mercury from deeper sediment (32-36 cm). Positive correlation is present between total Hg and clay content. Based on index of geoaccumulation (I(geo)) and Effects-Range Low (ER-L) value (150 ppb) it is considered that the sediments are till now unpolluted. As a consequence, there is less chance of ecotoxicological risk to organisms living in studied sediments. Two statistical methods were applied to determine T(Hg) anomalies. Box plot method showed one extreme and three outliers in S(1) at postmonsoon season. Two extremes were found at S(2) at 4-8 and at 32-36 cm in premonsoon period. In S(3) there was no anomaly by box plot method. MAD method was more sensitive than box plot method and T(Hg) anomaly was detected at 12-16 cm in S(3) during postmonsoon season. The data reported are useful baselines for T(Hg) in Sunderban mangrove wetland, India and would be of help in future sediment quality studies.
这是一份关于印度孟加拉湾东北部孙德尔本斯红树林湿地核心沉积物（粒径小于63微米）中总汞（T(Hg)）的初步报告。采用冷蒸气原子吸收光谱法（CVAAS）测定总汞。其浓度范围为9.8至535.1 ppb（纳克/克）。结果显示，在不同核心深度以及位于胡格利河（S(1)）、马特拉河（S(2)）和比迪亚达里河（S(3)）三条河流处的三个采样站，季风前和季风后月份存在差异。S(2)核心地下层（4 - 8厘米）中总汞浓度升高归因于汞从更深层沉积物（32 - 36厘米）的再迁移。总汞与粘土含量呈正相关。根据地积累指数（I(geo)）和效应范围低值（ER - L）值（150 ppb），认为这些沉积物目前未受污染。因此，生活在研究沉积物中的生物遭受生态毒理学风险的可能性较小。应用两种统计方法来确定总汞异常情况。箱线图法显示，季风后季节S(1)有一个极值和三个异常值。季风前时期，S(2)在4 - 8厘米和32 - 36厘米处发现两个极值。箱线图法显示S(3)没有异常。中位数绝对偏差（MAD）法比箱线图法更灵敏，在季风后季节检测到S(3)在12 - 16厘米处存在总汞异常。所报告的数据是印度孙德尔本斯红树林湿地总汞的有用基线，将有助于未来的沉积物质量研究。
