Background concentrations and quality reference values for potentially toxic elements in soils of Piauí state, Brazil

• Published in: Environmental monitoring and assessment Vol. 192; no. 11; p. 723
• Main Authors: Boechat, Cácio Luiz, Duarte, Lizandra de Sousa Luz, de Sena, Antonny Francisco Sampaio, do Nascimento, Clistenes Williams Araujo, da Silva, Ygor Jacques Agra Bezerra, da Silva, Yuri Jacques Agra Bezerra, Brito, Ana Clecia Campos, Saraiva, Paloma Cunha
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-11-2020; Springer Nature B.V
• Subjects: Anthropogenic factors; Antimony; Atmospheric Protection/Air Quality Control/Air Pollution; Cadmium; Chromium; Cobalt; Contamination; Copper; Earth and Environmental Science; Ecology; Ecotoxicology; Environment; Environmental Management; Environmental monitoring; Environmental science; Geology; Human influences; Iron; Lead; Molybdenum; Monitoring/Environmental Analysis; Nickel; Polls & surveys; Soil; Soil characteristics; Soil contamination; Soil pollution; Soil properties; Soil quality; Soil texture; Spatial distribution; Statistical methods; Surveying; Texture; Zinc; Brazil; Trace elements; Environmental monitoring; Soil quality guideline; Soil contamination
• DOI: 10.1007/s10661-020-08656-w
• EISSN: 1573-2959
• ISSN: 0167-6369

The background concentration of potentially toxic elements (PTE) in soils is influenced by the parent material composition and soil forming processes. The soil natural concentration of PTE is a first step to establish regulatory levels for the monitoring of these elements in soils suspected of contamination. In the present study, we performed a natural background concentration survey of PTE in soils of the Piauí state, Brazil. The study provides the basis for establishing soil quality reference values (QRVs) for a large area (over 251,000 km
2
) with different pedological features. A total of 262 geo-referenced soil samples (0.0–0.2 m) were collected in areas relatively undisturbed by human activity. The concentrations of Ba, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb, Sb, V, and Zn were determined by ICP-OES. Univariate statistical methods and multivariate exploratory techniques were used to understand the relationship between soil characteristics, geological features, and PTE concentrations in soils. The mean background concentrations of PTE in the soils were generally lower than those reported in other countries and/or other Brazilian states, and followed the order: Fe > Ba > V > Cr > Cu > Pb > Zn > Ni > Pb > Co > Mo > Sb > Cd. The main factors governing the concentrations of PTE in soils were the parent material and the soil texture. The different geological features in the study area influenced the spatial distribution of PTE and divided the state into three regions presenting low, high, and intermediate values. Given this geological and pedological complexity, we proposed establishing three sets of QRV rather than a single QRV for the whole state to avoid misinterpretation regarding the investigation of areas suspected of contamination. This background concentration survey contains a wealth of information that provides the basis for the soil guideline values in the state and supports future research on the impact of anthropogenic activities in soil contamination.