Arsenic in Latin America: Part II

Abstract

Long-term exposure to As through drinking water is an important health problem in Latin America (LA), causing both carcinogenic and non-carcinogenic effects (McClintock TR, Chen Y, Bundschuh J, Oliver JT, Navoni J, Olmos V, Villaamil Lepori E, Ahsan H, Parvez F (2012) Arsenic exposure in latinamerica: biomarkers, risk assessments and related health effects. Sci Total Environ 429:76–91). This chapter reviews information on health effects conducted in LA. It is estimated that, in this region, 14 million people are chronically exposed to As through drinking water and food. Lung cancer is the most studied adverse effect of As exposure in LA, followed by skin lesions, bladder cancer, and the effects of early exposure to As. Studies on As exposure and cancer development are well described in Chile, Mexico, and Argentina. According to studies conducted mainly in Mexico, an association between As exposure and diabetes is reported. Arsenic removal technologies investigated in LA over the last few decades rely on adaptation and improvement of methods involving simple physicochemical processes like adsorption, coagulation/precipitation, or ion exchange, all of them being more suitable for As(V) than for As(III) removal, which usually implies a preliminary oxidation step. However, new technologies are constantly under investigation, and several of them have been reported. For rural communities in LA, small-scale and household level, As removal systems are the only feasible short-term solution. Natural geological materials like iron oxides and hydroxides, calcite, clays, etc. can be used as effective, simple, and low-cost materials for As removal at the household level and for small communities. Natural organic materials are also the basis for suitable low-cost technologies. Sorption agents coming from plants and animal residues are also useful. Procedures using zerovalent iron from diverse materials are affordable and easy to operate and maintain. Other alternatives are capacitive deionization, phytoremediation, and constructed wetlands. An overview of the state of the art of technologies for As removal studied in LA will be given in this chapter.