The varieties of sargassum that reach the coasts of the country have concentrations of arsenic that exceed the limits established at the international level to be used in agricultural work and animal feeding. This is revealed by a study carried out by researchers from the Technological Institute of Santo Domingo (Intec) who analyzed the concentration of heavy metals in the algae.
Arsenic is a chemical element of the metalloid group and can be found naturally in air, water and soil. Arsenic exposure has been linked to various types of cancer.
The research, published in the scientific journal Marine Pollution Bulletin, consisted of collecting samples of the three varieties of algae that reach the country’s coasts on eight beaches, with the aim of analyzing the presence of heavy metals in their composition to determine the possibility of its use in agriculture.
Intec researchers detected the presence of eleven heavy metals, with iron, arsenic and zinc in the highest concentrations. Also cadmium in the samples from three of the beaches, nickel in five and lead in six.
Rolando Liranzo, Aris Mendis Gómez, Bolívar Gómez, Yusmel González-Hernández and Ulises Jauregui-Haza collected samples of the three varieties of sargassum that arrive in the country: S. fluitans III, S. nathans I and nathans VIII, in eight beaches of the national territory in the year 2021. It was the beaches of Bavarian and Punta Canain La Altagracia; Juan Dolio and guayacanesin San Pedro de Macoris; San Andres, in Santo Domingo; Nigua, in San Cristóbal; Enriquillo, in Barahona and Juancho in flints.
The research is part of the research papers produced by students of the PhD in Environmental Sciences offered at Intec.
The findings were compared with the two previous studies on the presence of metals in the algae that reach the coast of the island and it was found that the reported arsenic values are two times higher than those reported in samples collected in 2015 and 2019. cobalt, chlorine, cadmium, nickel and zinc values were lower; while for copper and lead they were in the same range as in previous studies.
“When comparing our results with the range of maximum values established for the use of arsenic in agriculture, soils and animal feed, we observe that, in all cases, the arsenic content in the samples studied is within that range or exceeds it, which constitutes a limitation for purposes of use in agriculture”, specifies the scientific publication.
In addition, he says that its use for these purposes could cause long-term damage to soils, and potentially pass up the food chain through food.
The investigation confirms the importance of continuing to conduct research on the chemical and organic composition of the sargassum that reaches the country’s coasts, before stimulating its use in agricultural work and animal feeding.
The two previous studies on the presence of heavy metals in sargassum were also carried out by Intec researchers: Fernández, Boluda, Olivera, Guillermo, Gómez, Echavarría, Mendis Gómez presented the study “Prospective elemental analysis of the algal biomass accumulated on the coasts from the Dominican Republic in 2015”; while Tejada-Tejada, Rodríguez-Rodríguez, Luis Rodríguez de Francisco, Omar Paino and Boluda presented “Lead, chromium, nickel, copper and zinc levels in sargassum species reached the coast of Dominican Republic during 2019”.
