Spatial dynamics of lindane concentration in a soil-plant system at the Bailín landfill site (Sabiñánigo, Huesca, Spain)

Hernández, Mauricio ; Fernández, Jesús ; Fontecha, Gustavo ; Gómez, Javier (Universidad de Zaragoza)

Resumen: Hexachlorocyclohexane (HCH) is an organochlorine synthetic substance composed of different isomers (α-, β-, γ-, δ-, and ε-HCH), but only γ-HCH isomer or lindane has insecticidal properties. From 1984 to 1992, INQUINOSA Company dumped HCH wastes in the Bailín landfill (Sabiñánigo, Spain), and in 2014 these HCH residuals were transferred to a secure landfill, dispersing a small amount of HCH-isomers in the surrounding area. To explore the spatial distribution of this pollution, we evaluated HCH concentration in the soil-vegetation system around the Bailín landfill site. Physicochemical properties showed a greater percentage of organic matter, cation exchange capacity, carbon content, and conductivity in soil samples, while only pH increased in subsoil samples. Our findings also revealed that the concentration of HCH-isomers is very heterogeneous in topsoil samples from <1 μg/kg to 780 μg/kg, whereas in subsoil samples fluctuated from <1 μg/kg to 70 μg/kg. Moreover, the accumulated HCH-isomers among species and plant tissues displayed large variations, with pine needles showing the greatest values. Interestingly, spatial distribution of HCH contamination was mainly concentrated close to the old landfill and secure landfill, suggesting that the removal processes largely influence soil contamination. Correlation of HCH levels in soil and plant material suggests that HCH uptake onto plants was accomplished either by translocation from soil via the root system or by deposition from air into the above-ground parts of the plants. As HCH-isomers are hydrophobic compounds that tend to be adsorbed by soil organic matter, HCH probably do not leach into groundwater, and the main sinks are surface runoff, volatilization, and degradation. However, more studies would be required to assess the potential sinks of HCH wastes in the Bailín landfill site.

Idioma: Inglés

DOI: 10.1016/j.envpol.2024.125198

Año: 2024

Publicado en: Environmental Pollution 363 (2024), 125198 [8 pp.]
ISSN: 0269-7491

Tipo y forma: Artículo (PostPrint)

Área (Departamento): Área Petrología y Geoquímica (Dpto. Ciencias de la Tierra)