Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ/IPSL), Gif-sur-Yvette, France; Structure et Fonctionnement des Systèmes Hydriques Continentaux (Sisyphe), Unité Mixte de Recherche 7619 (UPMC-CNRS-EPHE), Paris, France.
Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Unité Mixte de Recherche 8212 (CEA-CNRS-UVSQ/IPSL), Gif-sur-Yvette, France.
Sci Total Environ. 2014 Feb 1;470-471:608-17. doi: 10.1016/j.scitotenv.2013.10.009. Epub 2013 Oct 26.
Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in soils and their subsequent release in rivers constitute a major environmental and public health problem in industrialized countries. In the Seine River basin (France), some PAHs exceed the target concentrations, and the objectives of good chemical status required by the European Water Framework Directive might not be achieved. This investigation was conducted in an upstream subcatchment where atmospheric fallout (n=42), soil (n=33), river water (n=26) and sediment (n=101) samples were collected during one entire hydrological year. PAH concentrations in atmospheric fallout appeared to vary seasonally and to depend on the distance to urban areas. They varied between 60 ng·L(-1) (in a remote site during autumn) and 2,380 ng·L(-1) (in a built-up area during winter). PAH stocks in soils of the catchment were estimated based on land use, as mean PAH concentrations varied between 110 ng·g(-1) under woodland and 2,120 ng·g(-1) in built-up areas. They ranged from 12 to 220 kg·km(-2). PAH contamination in the aqueous phase of rivers remained homogeneous across the catchment (72 ± 38 ng·L(-1)). In contrast, contamination of suspended solid was heterogeneous depending on hydrological conditions and population density in the drainage area. Moreover, PAH concentrations appeared to be higher in sediment (230-9,210 ng·g(-1)) than in the nearby soils. Annual mass balance calculation conducted at the catchment scale showed that current PAH losses were mainly due to dissipation (biodegradation, photo-oxidation and volatilization) within the catchments (about 80%) whereas exports due to soil erosion and riverine transport appeared to be of minor importance. Based on the calculated fluxes, PAHs appeared to have long decontamination times in soils (40 to 1,850 years) thereby compromising the achievement of legislative targets. Overall, the study highlighted the major role of legacy contamination that supplied the bulk of PAHs that are still found nowadays in the environment.
多环芳烃（PAHs）在土壤中的积累及其随后在河流中的释放是工业化国家面临的一个主要环境和公共卫生问题。在塞纳河流域（法国），一些 PAHs 超过了目标浓度，而《 欧洲水框架指令》所要求的良好化学状况目标可能无法实现。本研究在一个上游小流域进行，该流域在一个完整的水文学年内采集了大气沉降物（n=42）、土壤（n=33）、河水（n=26）和沉积物（n=101）样本。大气沉降物中的 PAH 浓度似乎随季节变化，且取决于与城市地区的距离。它们在 60ng·L(-1)（秋季偏远地区）和 2380ng·L(-1)（冬季建成区）之间变化。流域内土壤中的 PAH 储量是根据土地利用估算的，林地土壤中 PAH 平均浓度为 110ng·g(-1)，建成区为 2120ng·g(-1)。它们的范围从 12 到 220kg·km(-2)。河流水相中的 PAH 污染在整个流域内保持均匀（72±38ng·L(-1)）。相比之下，悬浮物的污染则因流域内的水文条件和人口密度而异。此外，沉积物中的 PAH 浓度（230-9210ng·g(-1)）高于附近土壤中的浓度。在流域尺度上进行的年质量平衡计算表明，目前 PAH 的损失主要是由于流域内的耗散（生物降解、光氧化和挥发）（约 80%），而由于土壤侵蚀和河流输送导致的排放似乎不太重要。根据计算出的通量，PAHs 在土壤中的净化时间较长（40 至 1850 年），从而危及立法目标的实现。总的来说，这项研究强调了遗留污染的主要作用，它提供了目前环境中仍存在的大部分 PAHs。
