About this project

Arsenic is a naturally occurring contaminant in Galician rivers due to the metamorphic geology of the region. This project evaluates the spatial distribution of arsenic and other trace elements along the Nogueiredo stream in Castrelo de Miño (Ourense, NW Spain).

Different sample types were analysed including water, sediments, earthworms, leaves and wood using ICP-MS-TOF and MC-ICP-MS.

Interactive Maps

Arsenic distribution

Arsenic predictive model

Longitudinal profiles

Arsenic evolution along the stream

Strontium evolution along the stream

Data tables

Water samples - First sampling campaign

Multimatrix samples - Second sampling campaign

Key findings

  • Arsenic concentrations along the stream ranged from 7.6 to 16 µg/L
  • The legal limit for drinking water (10 µg/L) was exceeded in several sampling points
  • A strong negative correlation was found between dissolved As and Fe in sediments (rho = -1)
  • The thermal/mining area (m25) showed exceptional bioaccumulation of As and W in earthworms

Techniques

  • ICP-MS-TOF — simultaneous multielement analysis
  • MC-ICP-MS — high precision Sr isotopic ratios
  • R — statistical analysis and data visualization