Researchers from the UNR created a map of the country's population exposed to arsenic through water and found that there are 17 million individuals, a figure that exceeds previous findings by more than four times.
The project was carried out within the framework of the Interuniversity Network on Environment and Health of the Central Region, by Leandro Duarte, Laura De Gracia, Sergio Montico and Alejandro Oliva. After an exhaustive review, the prestigious scientific journal “Water and Health” agreed to publish this work that configures a new map of the situation in Argentina taking into account the indices established by the World Health Organization.
The population exposed to arsenic in the country has a history of one hundred years, initially with an impact on the skin, called chronic regional endemic hydroarsenicism, produced by the prolonged consumption of water with this contaminant. Over time, the clinical spectrum was expanded to include its association with certain types of cancer, congenital abnormalities, neurological diseases such as Alzheimer's and others. "There is a direct relationship: the departments that are most exposed have higher mortality rates from these diseases," says Oliva.
The information shows that “this problem is almost a pandemic in Argentina,” say the researchers, who believe that it could be prevented with more exhaustive controls on water quality, the implementation of arsenic removal measures with more accessible methodologies and lower costs than in the past, and public health measures that are the responsibility of national, provincial and municipal governments.
Data on arsenic levels in drinking water were widely scattered and not up-to-date. Two attempts to map the situation in this country had several limitations, as they referred to isolated values without specifying the population involved or because they did so by drawing a general distribution. The previous information mentions a total exposed population in this country of approximately 4 million inhabitants.
To carry out this project, the researchers analyzed data from twelve Argentine provinces where reliable published information existed. The information had certain requirements for inclusion: it had to be territorially representative, with a minimum of 30% of the population evaluated, with an evaluation of arsenic levels according to World Health Organization standards (10 μg/L) and with the evaluation having been carried out on drinking water. This allowed half of the provinces to be evaluated, equivalent to approximately 70% of the national population.
“The most complicated area is the western drift of Santa Fe and the southeastern drift of Córdoba. Santa Fe and Buenos Aires have 2 out of 3 inhabitants exposed to arsenic, more than 60% of the population. Córdoba does not reach 30% because the northwest takes water from other aquifers that come from springs and not from the aqueduct,” Oliva explains.
90% of this pollutant reaches the water naturally due to the erosion of rocks in aquifers. To a lesser extent, there is also a contribution from activities arising from industrial processes (mining, metal smelting, pesticides, wood preservatives, etc.)
The World Health Organization has defined a limit value for arsenic in water, the same being recommended for the concentration of this element in drinking water of 10 μg/L. In Argentina, the Argentine Food Code establishes a higher safety limit, reaching 50 µg/L. Many scientific evidences have shown that, between both limits, there is a significant risk for human health.
Originally, Argentina had adhered to the 10 microgram cut-off, but the municipalities argued that the filtering method was very expensive, required the use of a lot of electricity, and then they did not know what to do with the extracted arsenic. What was historically used was reverse osmosis, a membrane that removes arsenic.
But, as researchers explain, there are now new, simpler and cheaper methods for removing this contaminant. In this sense, some municipalities in the province of Santa Fe have a parallel network with the removed arsenic that is used only for consumption and the other for bathing, cleaning, etc., which highlights the importance of creating aqueducts. It should be noted that the water consumed in the city of Rosario from the Paraná River does not contain arsenic.
The Interuniversity Network on Environment and Health of the Central Region was created in 2016 between the six public universities of the region for the development of collaborative activities in different projects on the territory. They currently have two lines of research.
The first one refers to an ecoepidemiological study of infant mortality due to cancer in Argentina and its relationship with environmental variables. The situation of the child population under 15 years of age is different from the general population, in terms of types and prevalence of cancers. In addition, the regional differences are very wide, with the central region showing the highest rates at the national level. The general objective is to analyze the possible associations between infant mortality due to cancer, the areas planted and the levels of arsenic in drinking water in the Argentine provinces.
The other ongoing research is concerned with the eco-epidemiological relationships between environmental factors, socioeconomic conditions and neurodegenerative diseases in Argentina. The general objective is to study the possible associations between these diseases (Alzheimer's and Parkinson's), the areas planted and the levels of arsenic in drinking water, as well as the sociodemographic characteristics (education and socioeconomic) in the provinces of Argentina, particularly in the central region.
Journalist: Victoria Arrabal/Photographer: Camila Casero