Puerto Naos and La Bombillathe coastal neighborhoods of Los Llanos de Aridane, got rid of the lava flows but
still suffering from the effects of the eruption. The 1,500 residents of these towns continue to be evicted due to the high levels of carbon dioxide (C02) that they have been registering since November.
scientists and security forces They regularly go into ghost towns to analyze the composition of the air polluted by gases of volcanic origin.
Some and others are
wishing to glimpse a decrease in the concentrations of this gas but, for the moment, this does not happen and
lethal CO2 concentrations continue to be detected, even outdoors. “Unfortunately, we continue to register very high, but very high, rates of carbon dioxide at very specific points,” says Brigadier Esteban Morán circumspectly after measuring the levels of this gas in 14 enclaves of La Bombilla.
The agent is part of the GRS Unit number 8 of Tenerife, a team from the
Guard civiche specialized in RBQ, radiological, biological and chemical emergencies, which has been analyzing the composition of the air since the beginning of the volcanic eruption and sends the data to the Insular Operational Coordination Center (Cecopin) of La Palma.
Now the group focuses this work on La Bombilla. There, says Morán, the concentration of oxygen in the air is significantly reduced by the presence of carbon dioxide. "Usually,
air contains 20.9% oxygen. In La Bombilla it drops to 9%. It's very little», laments the brigade who assures that there are places with such low levels of oxygen that «it can be extremely dangerous to enter them without autonomous breathing equipment».
The civil guards Esteban Morán and Javier Nicolás protect themselves to take the measurements with autonomous breathing equipment. /
Morán is equipped with
back protector with straps, oxygen bottle and mask to measure with a portable sensor the concentration of carbon dioxide, carbon monoxide, sulphurous gases and explosive or flammable environments.
With this protection and accompanied by agent Javier Nicolás,
approaches the window of a cave house. It is ventilated because it has a second open window. A dozen meters from the house, the device alarm goes off. It means that carbon dioxide has exceeded 5,000 parts per million. in the same window,
registers 48,000 parts per million, with a drop in oxygen that reaches 12%. "Inside the house,
it would be impossible for a person to stay, they would fall in a few seconds», says the civil guard who detects the highest levels of CO2 in «the places closest to the mountainside, closed places, cave houses, sewers and alleys where there is little wind.
lethality of these concentrations can be seen in the appearance of animal remains. «
We have seen dead turtledoves, cats and lizards and they continue to appear. Today I have seen a bird in a place where it hadn't been until now”, acknowledges Morán who travels to La Palma to take these measurements every two weeks.
The agents of the Civil Guard coincide in La Bombilla with the scientists of the
Volcanological Institute of the Canary Islands (Involcan). They also analyze the gases there and in Puerto Naos, but continuously. They exchange impressions and data. They match.
None of them can give good news on a decrease in CO2 concentrations.
Normal is a content of 400 or 500 parts per million (ppm) of carbon dioxide in the air. And there
we are measuring 140,000 ppm in the street, sometimes we have reached 200,000 parts per million in open spaces», relates the Involcan geochemist, Pedro Hernández.
two gas measurement networks of Involcan draw a dark picture. "The problem here is quite complex: first, it is a large area and then there are points where the CO2 levels are maintained, in others they decrease and in others they increase", says the scientist. Currently, he points
ground zero is Playa Chica in Puerto Naos.
"Therethere is so much C02 that it is noticeable even visually, like when the asphalt is very hot. The heat changes the density of the air and you see that effect with the rippling image. There is so much gas there that it changes the density of the air and you can see it," says Hernández.
Involcán has two gas monitoring networks in the area. A non-instrumental one installed in Puerto Naos and formed by
45 alkaline traps containing potassium dioxide solutions that dissolve carbon dioxide. “They are installed inside buildings. They allow us to observe which areas have the highest level of carbon dioxide and the space-time variability. We can monitor the amount of CO2 they absorb," explains the geochemist.
Although these traps identify where the areas of greatest danger are and how they vary, this process is, at the moment, unpredictable. «
We have not yet understood the temporal pattern of this evolution.We haven't seen any signs of a general decline. Although we know that this process has to end one day, right now we don't know when it will be," he laments.
In addition to these traps, Involcan has a
instrumental network of CO2 concentration monitoring stations in Puerto Naos and La Bombilla. In this last locality there is also a different station that allows measuring the flow of carbon dioxide that comes out of a cave. "It tells us how much carbon dioxide is being emitted through the soil and we can see over time whether it is increasing or decreasing.
Now, in La Bombilla the emission is constant, between 8 and 10 tons a day», comments the geochemist on the data offered by this particular station.
“This network allows us
measure concentration continuously, every ten to fifteen minutes, and compare the results with the external meteorological parameters to know how they are modulating the concentration levels”, explains Hernández about the stations; four installed in La Bombilla and another eight in Puerto Naos, in collaboration with the University of the Azores, the General Directorate of Emergencies and the University of Düsseldorf.
According to Hernandez,
the problem of CO2 emission in these coastal towns began in mid-November, two months after the onset of the eruption. Just then a lava leak opened to the south of the cone that affected part of the cemetery located in Las Manchas.
Involcan geochemist Pedro Hernández calibrating a portable sensor. /
«In those days, suddenly, the presence of CO2 in the area rose. There was some kind of fracturing that started gas coming out.
It is not yet known what happened», says the Involcan scientist.
There are those who doubt the health condition of these CO2 concentrations. "In the case of carbon dioxide, in small concentrations it does nothing, but
above 14% in air it is lethal. Here we have found points with 70% CO2 in the air. In Puerto Naos, the maximum we have found is 55% indoors. Outdoors, even 30%, "explains Hernández.
“There are people here who have had respiratory problems. If you are continuously breathing 5,000 or 6,000 parts per million of CO2 -approximately 0.5 or 0.6%- you begin to have health problems”, he adds, recalling the case of an engineer who participated in the installation of the desalination plants in Puerto Naos. “He was the one who discovered the problem. He messed with an autonomous team in a garage and, halfway through, they had to leave. He began to feel his legs burning. It was in that garage that a concentration of 55% CO2 was measured.
Imagine if someone came in to get a car. there it stays», assures the scientist.
Confusion and hoaxes
the neighbors are fed up to wait for the return to their homes and businesses and are increasingly incredulous. In fact
have even accused scientists of falsifying reality. “People are being confused. Some irresponsible people are encouraging falsehoods on the networks and on whatsapp. They say this is all a lie. A few months ago we were accused - they told my partner - of killing cats in El Paso and Los Llanos and of putting the corpses here to bring evidence, "laments the geochemist.
This tension has forced to convene a meeting in which the experts will explain the problem to the evicted of the gases. The objective is to avoid a planned protest at the entrance to Puerto Naos that could endanger the life of those who, listening to voices unrelated to the emergency, risk entering a potentially lethal environment.
Scientists explain the situation to those affected
The scientists will explain to the residents of Puerto Naos and La Bombilla the problem that the high concentrations of CO2 are generating in these coastal towns, which prevents them from returning to their homes and businesses with safety guarantees. The meeting, convened by Reviving the Valley this Tuesday, at 6:00 p.m., in the Camilo León fighting area of Los Llanos de Aridane, aims to alleviate uncertainty and “the growing social controversy” among the affected population that cannot return due to the existence of gases incompatible with the presence and human activity. In recent days, the neighbors, through social networks, are questioning the closure of access to both towns and are considering calling a protest.