Data for “Intra- and inter-site variability of soil contamination in road shoulders – Implications for maintenance operations”

The reported data have been acquired within a research project investigating soil contamination in vegetated road shoulders. The methodology was designed to assess (i) the spatial distribution of three metals (copper, lead and zinc) and 16 PAHs (classified as priority pollutants by the US-EPA) within each sampled site, and (ii) whenever possible, influencing factors for the inter-site differences in contamination levels. The study area covers approximately 6,000 km² in the eastern part of the Paris region (France), with a strong urbanization gradient from east to west. Forty road segments were selected to encompass most of the territory’s soil types, environments (scattered dwellings, open countryside, forest), and traffic characteristics. At each site, soil samples were collected at four to five distances from the road, depending on the shoulder width. For each distance, a composite sample was formed from 6 evenly spaced points along a transect parallel to the road. The targeted depth corresponded to the upper 5 centimeters, however in some cases the presence of the road sub-base only allowed the collection of a surface sample (0-2 cm). All samples were analyzed for metals, whereas only two samples from each site could be analyzed for PAHs due to cost constraints: it was chosen to retain (i) a composite sample formed by merging subsamples collected at 0 and 0.3 m, and (ii) a sample collected on the opposite side from the road. Further details are provided in the appended file entitled “Data description”. The other files present: • Site characteristics: site index (number from 1 to 40 and official French nomenclature), GPS coordinates of the site, annual average daily traffic, truck fraction. • Metals and PAHs: site index, sampling distance, concentrations of each individual substance analyzed in the corresponding sample. The results are presented and discussed in the following research article: D. Tedoldi, R. Charafeddine, P. Branchu, E. Thomas, M.-C. Gromaire (2021) Intra- and inter-site variability of soil contamination in road shoulders – Implications for maintenance operations. Science of the Total Environment.所报道的数据是在一项旨在研究植被道路肩部土壤污染的研究项目中获得的。该研究方法旨在评估（i）在每个采样点内三种金属（铜、铅和锌）及十六种多环芳烃（根据美国环保署的优先污染物分类）的空间分布，以及（ii）在可能的情况下，影响不同采样点之间污染水平差异的影响因素。研究区域位于法国巴黎地区东部，面积约为6,000平方公里，从东到西呈现出明显的城市化梯度。选定了四十个路段，以覆盖该地区的大部分土壤类型、环境（散居住宅、开阔乡村、森林）和交通特征。在每个采样点，根据路基肩宽，在距离路基四到五处采集土壤样本。对于每个距离，从与路基平行的横断面上的六个均匀分布的点中形成一个混合样本。目标深度对应于上部5厘米，但在某些情况下，由于路基基层的存在，仅允许采集表面样本（0-2厘米）。所有样本均进行了金属分析，而由于成本限制，每个站点只能分析两个样本的多环芳烃：选择保留（i）由在0米和0.3米处采集的子样本合并而成的混合样本，以及（ii）从路基对面采集的样本。更详细的说明见附文件“数据描述”。其他文件包括：• 站点特征：站点指数（从1到40的数字和官方法国命名法）、站点GPS坐标、年平均日交通量、卡车比例。• 金属和多环芳烃：站点指数、采样距离、分析样本中每种物质的浓度。研究结果在以下研究文章中呈现和讨论：D. Tedoldi, R. Charafeddine, P. Branchu, E. Thomas, M.-C. Gromaire（2021）道路肩部土壤污染的站内和站间变异性——对维护作业的启示。Science of the Total Environment。