The application of statistical modelling is still infrequent in mercury research in peat, despite the ongoing debate on the weight of the diverse factors (climate, peat decomposition, vegetation changes, etc.) that may affect mercury accumulation. One of the few exceptions is the Hg record of Pinheiro mire (souheast Brazil). Previous studies on this mire modeled mercury using principal components regression and partial least squares. These methods assume independence between factors, which is seldom the case in natural systems, thus hampering the identification of mediating effects and interactions. To overcome these limitations, in this reserach we use structural equation modelling (PLS-SEM) to model mercury and bromine peat records - bromine has been used in some investigations to normalize mercury accumuation. The mercury model explained 83% of the variance and suggested a complex control: increased peat decomposition, dust deposition and humid climates enhanced mercury accumulation, while increased mineral fluxes resulted in a decrease in mercury accumulation. The bromine model explained 90% of the variation in concentrations: increased dust depositiopn and peat decomposition promoted bromine accumulation, while time (i.e. peat age) promoted bromine depletion. Thus, although mercury and bromine are both organically bound elements with relevant atmospheric cycles the weights of the factors involved in their accumulation differed significantñy. Our results suggest caution when using bromine to normalize mercury accumulation. PLS-SEM results indicate a large time dependence of peat decomposition, catchment mineral fluxes, long-term climate change, and atmospheric deposition; while atmospheric dust, mineral fluxes and peat decomposition showed high to moderate climate dependecy. In particular, they also point to a relevant role of autogenic processes (i.e. the build up and expansion of the mir within the catchment), which controlled local mineral fluxes; an aspect that has seldon been considered.

尽管人们一直在争论可能影响汞累积的各种因素（气候，泥炭分解，植被变化等）的权重，但在泥炭中的汞研究中仍然很少使用统计模型。几个例外之一是Pinheiro泥沼（巴西东南部）的汞记录。以前关于此泥潭的研究使用主成分回归和偏最小二乘来模拟汞。这些方法假定因素之间是独立的，这在自然系统中很少见，因此妨碍了对中介作用和相互作用的识别。为了克服这些限制，在此研究中，我们使用结构方程模型（PLS-SEM）对汞和溴煤泥炭记录进行建模-在某些研究中已使用溴对汞累积进行标准化。汞模型解释了83％的方差，并提出了一个复杂的控制措施：泥炭分解增加，粉尘沉积和潮湿气候增加了汞的积累，而矿物质通量的增加导致汞积累的减少。溴模型解释了90％的浓度变化：灰尘沉积和泥炭分解的增加促进了溴的积累，而时间（即泥炭的年龄）促进了溴的消耗。因此，尽管汞和溴都是具有相关大气循环的有机结合元素，但其积累所涉及的因素的权重却存在显着差异。我们的结果表明在使用溴使汞积累正常化时要谨慎。PLS-SEM结果表明泥炭分解，集水区矿物通量，长期气候变化与时间有很大关系，和大气沉积；大气中的尘埃，矿物通量和泥炭分解显示出对气候的高中度依赖。特别是，它们还指出了自发过程的相关作用（即流域内mir的形成和扩展），该过程控制了局部矿物通量。已经考虑过的一个方面。