Dirección de Seguridad y Medio Ambiente, Instituto Mexicano del Petróleo, Eje Central Lázaro Cárdenas No. 152, San Bartolo Atepehuacan, México, D.F., 07730, Mexico.
Environ Monit Assess. 2014 Jan;186(1):307-24. doi: 10.1007/s10661-013-3375-0. Epub 2013 Aug 22.
During the last two decades, sediments collected in different sources of water bodies of the Tehuantepec Basin, located in the southeast of the Mexican Pacific Coast, showed that concentrations of heavy metals may pose a risk to the environment and human health. The extractable organic matter, geoaccumulation index, and enrichment factors were quantified for arsenic, cadmium, copper, chromium, nickel, lead, vanadium, zinc, and the fine-grained sediment fraction. The non-parametric SiZer method was applied to assess the statistical significance of the reconstructed metal variation along time. This inference method appears to be particularly natural and well suited to temperature and other environmental reconstructions. In this approach, a collection of smooth of the reconstructed metal concentrations is considered simultaneously, and inferences about the significance of the metal trends can be made with respect to time. Hence, the database represents a consolidated set of available and validated water and sediment data of an urban industrialized area, which is very useful as case study site. The positive matrix factorization approach was used in identification and source apportionment of the anthropogenic heavy metals in the sediments. Regionally, metals and organic matter are depleted relative to crustal abundance in a range of 45-55 %, while there is an inorganic enrichment from lithogenous/anthropogenic sources of around 40 %. Only extractable organic matter, Pb, As, and Cd can be related with non-crustal sources, suggesting that additional input cannot be explained by local runoff or erosion processes.
在过去的二十年中，从位于墨西哥太平洋海岸东南部的特万特佩克盆地不同水源采集的沉积物表明，重金属浓度可能对环境和人类健康构成威胁。本文针对砷、镉、铜、铬、镍、铅、钒、锌和细颗粒沉积物，量化了可提取有机物、地质累积指数和富集因子。采用非参数 SiZer 方法评估了随时间重建金属变化的统计显著性。这种推断方法似乎特别自然，非常适合温度和其他环境重建。在这种方法中，同时考虑了一系列平滑的重建金属浓度，并可以根据时间对金属趋势的显著性进行推断。因此，该数据库代表了一个具有城市工业化地区可用且经过验证的水和沉积物数据的综合集合，作为案例研究地点非常有用。本文采用正矩阵因子分解方法识别和源解析沉积物中的人为重金属。在区域上，金属和有机物相对于地壳丰度的含量减少了 45-55%，而来自岩石/人为源的无机物的含量增加了 40%。只有可提取有机物、Pb、As 和 Cd 可以与非地壳源有关，这表明额外的输入不能用当地的径流或侵蚀过程来解释。
