Methylmercury (MeHg) is the most toxic and dangerous form of mercury occurring in the environment. MeHg is highly bioaccumulative in organisms and undergoes biomagnification via the food chain. In the Baltic Sea munition dumpsites, methylmercury can be formed from mercury fulminate contained in primary explosives, as environmental conditions there favour methylation. MeHg in analysed sediments ranged from 19 to 2362 pg g⁻¹d.w., the concentration of mercury (Hg_TOT) ranged from 4 to 294 ng g⁻¹ d.w., and the values of MeHg/Hg ratio ranged from 0.1 to 2.0%. The obtained results confirmed that munition dumpsites are a source of mercury. The concentration of MeHg is elevated in a wider area than immediately next to dumped munitions. Presented results suggest that physical processes responsible for sediment and near-bottom water movement are diffusing MeHg signal, making munition dumpsites rather a diffuse source of MeHg than a number of point sources associated with particular munitions.

甲基汞（MeHg）是环境中存在的最具毒性和危险性的汞形式。甲基汞在生物体内具有很高的生物蓄积性，并通过食物链进行生物放大。在波罗的海弹药堆放场中，主要环境炸药中的富汞化汞可形成甲基汞，因为那里的环境条件有利于甲基化。分析沉积物中的MeHg为19至2362 pg g ^-1 d.w.，汞的浓度（Hg _TOT）为4至294 ng g ^-1dw，MeHg / Hg比值的范围从0.1到2.0％。获得的结果证实，弹药场是汞的来源。MeHg的浓度比抛弃的弹药紧邻的范围更大。提出的结果表明，造成沉积物和近底部水运动的物理过程正在扩散MeHg信号，使弹药堆放场成为MeHg的扩散源，而不是与特定弹药相关的许多点源。