Assessment of arsenic and fluorine in surface soil to determine environmental and health risk factors in the Comarca Lagunera, Mexico Article uri icon

abstract

  • Total, bioaccessible and mobile concentrations of arsenic and fluorine are determined in polluted surface soil within the Comarca Lagunera region using standardized protocols to obtain a full description of the environmental behavior for these elements. The composition of mineral phases associated with them is evaluated with microscopic and spectroscopic techniques. Mineralogical characterizations indicate that ultra-fine particles (<1–5 μm) including mimetite-vanadite (Pb5(AsO4)3Cl, Pb5(AsO4, VO4)3Cl)-like, lead arseniate (Pb3(AsO4)2)-like and complex arsenic-bearing compounds are main arsenic-bearing phases, while fluorite (CaF2) is the only fluorine-bearing phase. Total fluorine and arsenic concentrations in surface soil range from 89.75 to 926.63 and 2.7–78.6 mg kg−1, respectively, exceeding in many points a typical baseline value for fluorine (321 mg kg−1), and trigger level criterion for arsenic soil remediation (20 mg kg−1); whereas fluoride and arsenic concentrations in groundwater vary from 0.24 to 1.8 mg L−1 and 0.12–0.650 mg L−1, respectively. The main bioaccessible percentages of soil in the gastric phase (SBRC-G) are estimated for arsenic from 1 to 63%25, and this parameter in the intestinal phase (SBRC-I) fluorine from 2 to 46%25, suggesting human health risks for this region. While a negligible/low mobility is found in soil for arsenic (0.1–11%25), an important mobility is determined for fluorine (2–39%25), indicating environmental risk related to potential fluorine release. The environmental and health risks connected to arsenic and fluorine are discussed based on experimental data. © 2017 Elsevier Ltd

publication date

  • 2017-01-01