Environmental Risk Assessment of Arsenic and Fluoride in the Chaco Province, Argentina: Research Advances

Abstract

The arsenic (As) and fluoride (F⁻) concentration in groundwater and potential adverse human health risk was investigated in the Central-West Region of the Chaco Province, northern Argentina. The mean concentration of As in shallow groundwater was 95 μg/L, where 76% of samples exceeded the World Health Organization (WHO) guideline value of 10 μg/L, while in deep groundwater it was 90 μg/L, where 63% samples exceeded 10 μg/L. For As health risk assessment, the average daily dose, hazard quotient (HQ), and cancer risk were calculated. The values of HQ were found to be >1 in 77% of samples. This level of contamination is considered to constitute a high chronic risk compared with U.S. Environmental Protection Agency (EPA) guidelines. Further, a significant portion of the population has lifetime carcinogenic risk >10⁻⁴ and may suffer from cancer. A positive correlation was observed between As and F⁻ in groundwater. The Código Alimentario Argentino (CAA) suggested a limit of F⁻ in drinking water as low as 0.8 mg/L under tropical environmental conditions; however, in shallow (39%) and deep groundwater (32%), samples exceeded these values. Exposure to F⁻ was calculated and compared with the adequate intake of minimal safe level exposure dose of 0.05 mg/kg/d and it was noted that 42% of population may be at high risk of fluorosis. Chronic exposure to high As and F⁻ levels in this population represents a concern due to possible adverse health effects attributed to these elements.

Assessment of Heavy Metals Concentration in Arsenic Contaminated Groundwater of the Chaco Plain, Argentina

“…Detailed information of the arsenic concentration in the groundwater of the CentralWest region of Chaco is available in recent publications; high fluorine (F) and As contents in drinking waters have also been reported [11,16]. In addition, a positive correlation between As and F has been found ( 2 = 0.66).…”

“…It covers an area of 1500 km 2 , and approximately 0.10 million population [11]. Presidencia Roque Sáenz Peña (90000 inhabitants), located between 26 ∘ 47 27 latitudes S and 60 ∘ 26 29 longitudes W, is the most important town where we could find an economy based on agricultural and livestock exploitation.…”

“…The Chaco-Pampean plain is the largest one in Latin America and one of the largest geographic units in the world affected by As-contaminated groundwater [10]. In the Chaco plain (north of the ChacoPampean plain), the major source of arsenic in groundwater is chemical weathering of the rocks, and no anthropogenic sources of contamination have been reported [11].…”

“…Particularly, it has been identified that there are elevated As concentrations in groundwater and reported in different regions of Argentina such as La Pampa [1], Buenos Aires [9], Chaco [11], Cordoba [12], Santiago del Estero [13], Santa Fe [14], and Tucumán [15] Provinces. Detailed information of the arsenic concentration in the groundwater of the CentralWest region of Chaco is available in recent publications; high fluorine (F) and As contents in drinking waters have also been reported [11,16].…”

Ingestas diarias de selenio a partir de su cuantificación en alimentos cocinados en una región endémica afectada por arsenicismo en Argentina

“…El arsénico es un tóxico ampliamente distribuido en el mundo, es considerado carcinogénico para humanos y se clasifica en el grupo 1 según 14 . La ingestión crónica de aguas arsenicales provoca la enfermedad llamada HACRE (hidro/arsenicismo crónico regional endémico) 15,16 , además, de otras patologías como astenia, debilidad muscular, cefalea, neuropatías periféricas, alteraciones hepáticas y renales, deterioro del sistema nervioso central, leucemias, diversos tipos de cáncer (pulmón, riñón, vejiga, piel), desordenes cardiovasculares, hipertensión entre otros 17,18,19 . La vía de ingreso principal al hombre es mediante el agua de consumo y los alimentos 20 .…”