Portuguese scientist to assess mercury pollution in Yanomami rivers | Brazil

A Portuguese scientist will participate in a joint mission of the European Union and the United Nations, initiated after a request from the Brazilian Ministry of the Environment, to analyze the mercury pollution that contaminates the water of rivers and streams in the territory of the Yanomami indigenous people, in Brazil. This heavy metal is very toxic, but it is used by illegal miners to separate and extract gold grains.

“Mercury has not been used in Europe for a long time, even mercury thermometers have been banned. But prospectors use it in rough quantities, to concentrate the gold, which is extracted from the water lines. The mercury goes directly into the water courses, it has no chance”, explained to PÚBLICO the geochemist Rita Fonseca, coordinator of the AmbiTerra Laboratory at the University of Évora.

Rita Fonseca, professor at the Department of Geosciences at the University of Évora, was chosen by the United Nations Joint Unit for the Environment/OCHA and the European Union’s Emergency Response Coordination Center (ERCC) as an environmental specialist to help the Brazilian Government to deal with contamination of rivers and streams in the Yanomami territory (Roraima state) by mercury, which is a huge public health problem.

To get an idea of ​​the scale of the problem, let’s say that an investigation carried out by the Brazilian Federal Police and released by the site G1 da Globo in June 2022, concluded that four rivers in the region have a very high level of contamination: 8600% higher than the stipulated maximum for water for human consumption. There is no safe level of exposure to mercury, but an indicator from the World Health Organization is used, which considers that concentrations above six micrograms of mercury per gram of hair can have serious consequences for health.

Rita Fonseca in her laboratory at the University of Évora

This was the indicator used in 2016 in a study by the National School of Public Health/Osvaldo Cruz Foundation, in collaboration with a Yanomami indigenous association, carried out in 19 villages, which detected high levels of contamination by this heavy metal, left in the environment by illegal mining. , the search for gold in indigenous lands, which is prohibited but was encouraged during the government of Jair Bolsonaro. In one village, levels were found at which mercury intoxication was measured up to 15.5 micrograms per gram of hair, 6.8 in children under five and 16 in pregnant women.

“Mercury is a highly toxic heavy metal, and its damage is usually serious and permanent: it can cause direct changes in the central nervous system, causing cognitive and motor problems, loss of vision; in addition to kidney, heart and reproductive system implications”, said, at the time of the publication of the work, Paulo Bastos, one of the authors of the study to Journal of the National School of Public Health Brazilian. In pregnant women, mercury reaches the fetus and can cause malformations and other complications.

Take everything you need

This pollution and the illegal entry of miners into the territory of the Yanomami – it is estimated that there are 20,000 – are factors that have contributed to the serious humanitarian crisis that this indigenous people is experiencing, and whose true dimension was only revealed with the entry into office of the government of Lula da Silva

The UN responded to a request for help from the Brazilian Ministry of the Environment to deal with this situation, which contacted the EU Emergency Response Coordination Centre. This entity contacted the various countries of the Union, in search of mercury contamination and decontamination experts. “Here in Portugal, they asked the Civil Protection, which I think has a connection with them and the Civil Protection asked the Portuguese Environment Agency if they had any specialist in the area”, says Rita Fonseca, to explain how they reached her.

The regional division of APA do Alentejo knew her, she was contacted and she sent her CV. That seemed to fit like a glove. “I’ve worked many times in Brazil, including in this part of mining contamination. And I also worked at amazon”, advances the scientist.

His name was quickly accepted, and he realized that the first team that will be sent to the Amazon to analyze the contamination of water lines by mercury will be just two people, Rita Fonseca and a Dutch scientist, Gerhard Winters, from the company CRUX Engineering. “We are just two people. He has been an ERCC expert several times and is an environmental physical geographer specializing in mathematical modelling. Complements my expertise”, explains the researcher from the University of Évora.

In principle, the mission will take place in phases. First, the scientists who will collect samples, Rita Fonseca and Winters, will advance. “We make a diagnosis and we have to make a report. And from there it will be verified who can join us, in another phase”, he explains.

“Now we are both trying to plan the mission, because this is a complicated thing. It takes time because we usually have to take almost everything we need. Because if not, it is always very complicated to get it there”, stresses the scientist. “I just wanted to know what area we’re going to work on. Because it’s one thing to work in a river that’s 20 meters deep, it’s another thing if it’s 20 or 40 centimeters deep. It has nothing to do with it”, advances Rita Fonseca.

Abandoned and contaminated mining site

There is still no date for the trip. “I put some pressure on it not to be held in March or April, because those are the months with the heaviest rain in the Amazon. I’ve worked there and I know what the rain is like. It is impossible to work, because the rivers get too high and it becomes dangerous. Us with loads of equipment inside a boat, because this is for working on a boat”, she adds. Her suggestion is that the mission take place in the month of May.

To begin with, Ibama – the Brazilian Institute for the Environment and Renewable Natural Resources is considering that scientists should not even enter the territory of the Yanomami, for security reasons. “At this stage, they think it’s better to analyze places outside the reserve that receive water lines affected by mining”, explains the researcher.

“What I’m thinking will be my job will be to do a sampling in which I have to collect sediments from the bottom, from the margin and from the water column, then do a chemical characterization, the kind they do at the moment. I have to take my probes to do that. I have to see if the mercury is in a mobile or immobile phase [é um metal pesado que se pode derreter, passar de sólido para líquido e de líquido para gás]that I can see soon.”

What he will focus on finding is “the most toxic form of mercury, methylmercury [é solúvel em lípidos e consegue atravessar membranas de seres vivos, danificando o sistema nervoso. Os seus afeitos são cumulativos, quanto maior a exposição maior a quantidade que se armazena no organismo]”, he explains.

But he is also thinking of bringing samples to study in his laboratory at the University of Évora. “I’ve already asked if it would be possible for the United Nations, or the European Union, to finance portable mercury analysis equipment, so as not to bring an immensity of samples”, he reports.

immobilize the mercury

After studying mercury concentrations, what can be done with rivers contaminated with mercury in the Amazon? “We have to see how mercury is distributed, in what form it is, because there is a more mobile and a less mobile form. It will be necessary to carry out a series of tests, I do some here, on a laboratory scale, to see which material is capable of immobilizing it, of preventing it from passing into the water column”, answers Rita Fonseca. The aim is to stop the chain of contamination of living beings from mercury pollution.

“There are materials that are thrown into the rivers, which will swell and incorporate these polluting elements. These are advanced remediation techniques. This is what you can try to do”, says the researcher. But getting the contaminant out of waterways will be very difficult. “The mercury will not leave there.”

Mercury is bioaccumulated, that is, it gradually accumulates in the body, in the tissues of contaminated animals or plants and enters the food chain. “When it is in the water or sediments, living beings will feed on the mercury particles, which are in the most toxic form that is methylmercury, and will incorporate them into their bodies.”

When fish eat these organisms, they are also contaminated, and when they are eaten in turn, the mercury moves up another notch in the food chain. Thus, regrets the researcher, “the Indians are dying because they eat the fish”. “Mercury is an element that is bioaccumulated in organisms and progressively gets higher concentrations”, she summarizes.

But these actions will be worth little if the most important thing is not done. “It’s going to be very difficult, if they don’t put an end to illegal mining, it’s not worth trying to clean the rivers”, says Rita Fonseca. “These are processes that take many years to try to remedy, but you have to stop the source, because if you keep releasing mercury, it’s not worth much, is it?”

Leave a Comment

I want to Sell this domain contact at [email protected]