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.