Human Health Risk and Bioaccessibility of Arsenic in Wadis and Marine Sediments in a Coastal Lagoon (Mar Menor, Spain)

Abstract

This study evaluates the potential health risks posed by geogenic arsenic in environments suitable for leisure activities, such as walking, bathing, and playing, for adults and children alike, as well as in neighbouring agricultural areas. The study includes an analysis of environmental characteristics and the main stream originating in the adjacent mining area, with water and sediment samples taken. The study area is representative of other areas in the vicinity of the Mar Menor Lagoon, which is one of the largest and most biodiverse coastal lagoons in the Mediterranean Sea. The general characteristics of the soil and water were determined for this study, as was the concentration of As in the soil and water samples. A granulometric separation was carried out into four different fractions (<2 mm, <250 µm, <100 µm, and <65 µm). The mineralogical composition, total As content, and bioaccessible As content are analysed in each of these fractions. This provides data with which to calculate the danger of arsenic (As) to human health by ingestion and to contribute to As bioaccessibility studies and the role played by the mineralogical composition and particle size of soil ingestion. The conclusions rule out residential use of this environment, although they allow for eventual tourist use and traditional agricultural use of the surrounding soils.

Keywords: arsenic; bioaccessible fraction; gastrointestinal phases; mineralogy; risk.

Figure 1

Localisation zone.

Figure 2

Mineralogical composition of Rambla del Beal.

Figure 3

Summary of the mineralogical composition from Los Nietos.

Figure 4

Arsenic mobilisation map.

Figure 5

Total arsenic in the soils (mg/kg).

Figure 6

As bioaccessibility (%) soils.

Figure 7

Main processes taking place in the Beal wadi.

Figure 8

Circle of correlations between the mineralogical composition of the soil and the bioaccessible arsenic in the stomach (S.P.) and intestinal (I.P.) phases of digestion.

Figure 9

Principal Component Analysis (mineralogical composition and As content).

Figure 10

Graphically summarises the residual plots for bioaccesibility.