Strong Acid Mixture and Sequential Geochemical Arsenic Extractions in Surface Sediments from the Santa Maria La Reforma Coastal Lagoon, Mexico: A Bioavailability Assessment

• Published in: Archives of environmental contamination and toxicology 2016-02, Vol.70 (2), p.348-360
• Main Authors: Rivera-Hernández, José R, Green-Ruiz, Carlos
• Format: Article
• Language: English
• Subjects: Acids; Analysis; Arsenic; Arsenic - analysis; Arsenic content; atomic absorption spectrometry; Atomic absorption spectroscopy; Bioavailability; Biota; Carbon; Carbonates - analysis; coastal water; Coasts; Contaminated sediments; Earth and Environmental Science; Ecotoxicology; Energy consumption; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring; fluorescence; Freshwater; Geologic Sediments - chemistry; Iron; Lagoons; Manganese; Manganese - analysis; Marine ecology; Mexico; Monitoring/Environmental Analysis; Organic carbon; Oxidation; playas; Pollution; River discharge; River flow; rivers; Sediment samplers; Sediments; Soil Science & Conservation; Spectral analysis; Spectrometry; Studies; Toxicity; Water analysis; Water Pollutants, Chemical - analysis
• ISSN: 0090-4341; 1432-0703
• DOI: 10.1007/s00244-015-0253-5

Thirty-three sediment samples were collected from the Santa Maria La Reforma coastal lagoon and digested by way of a strong acid mixture and sequential arsenic (As)-extraction method to determine the arsenic (As) content and bioavailability. The As content was determined by atomic fluorescence spectrometry. In addition, grain-size analyses were performed, and organic carbon, carbonate, and iron (Fe) and manganese (Mn) concentrations were determined. Fe and Mn determination was performed by atomic absorption spectroscopy. A Pearson correlation matrix and As enrichment factors were calculated. Sediment concentrations from Santa Maria La Reforma ranged from 3.6 to 25 µg As g⁻¹ with an average of 13.4 ± 7.6 µg As g⁻¹. The highest values were observed in the northern (Playa Colorada), north-central (Mocorito River discharge zone), and southern zones (“El Tule” agricultural drain). Most samples were classified as exhibiting no or minor As enrichment and were lower than the threshold effect level (TEL; 7.24 µg g⁻¹) for biota (MacDonald et al. in Ecotoxicology 5:253–278, 1996). Low bioavailable As values (