The University of Aveiro assesses the environmental risks of heavy metals in Cape Verde
José Pichel Andrés/DICYT The Geoscience Department of the University of Aveiro has carried out a study on heavy metals in the Cape Verde Islands with the objective of drawing up geochemical maps of the islands and assessing possible environmental risks. This information is part of an international project and will allow improved decision-making on soil use, environmental protection, and the health of the inhabitants, as well as serving as a reference for other countries.
The research team of Marina Cabral Pinto is carrying out field studies in which it collects rocks, soil, sediments from streams, and water in order to analyse the samples in the laboratory and determine the concentrations of elements that are potentially dangerous to human health, such as heavy metals. From this starting point the scientists draw up maps and assess whether these concentration are of natural or anthropogenic origin or both.
“On studying the chemical concentrations of some elements in sediments, soil, or water we analyse whether there is any risk to human health owing to exposure to high concentrations or prolonged exposure to low concentrations. An example is the risk caused by exposure to carcinogenic metals”, the researcher explained to DiCYT. The team is also studying the presence of these elements in human biological samples such as urine, blood, or hair taken from areas at risk.
One of its most recent studies, which has been published in the Journal of African Earth Sciences, has led this research group to Cape Verde as part of the International Geoscience Programme promoted by the UNESCO and the International Union of Geological Sciences, the objective of which is to create an universal geochemical database and draw up a world geochemical atlas. These studies make it possible to distinguish contamination caused by human beings from that of other origins. This is particularly useful in countries such as Cape Verde where there are still no regulations regarding land use.
The results of the analyses carried out on the island of Santiago, the largest of the archipelago, have revealed that the distribution of harmful metals is closely linked to geology, which probably indicates a natural origin. However, “it has not been completely ruled out" that the concentration of some elements is related to human activities in some population centres or to agriculture. This is the case of arsenic, mercury, cadmium, zinc, and lead.
Elements such as cobalt, chromium, nickel, copper, and vanadium may represent greater risks to the environment and agriculture, but the research team of Marina Cabral Pinto is also very interested in finding out the influence of metals on human health. This is what is known as geomedicine. “It is known that some diseases may be caused or encouraged by the excess or lack of certain elements”, the researcher comments. “We have been studying the links between some neuropathologies such as Alzheimer's and Parkinson's diseases, together with the risks of contracting cancer, with some chemical elements with which the population is in contact in its normal environment”, she adds.
The study has important local applications as it provides reference data for future research in Cape Verde and also for the development of its legislation, but it also allows comparison with other countries with similar geology and climate. The scientists hope to complete their work on other islands of the archipelago.