Destruction of diversity and health: fires devastate life in the Pantanal and beyond

The largest continental wetland on the planet and home to a biodiversity as diverse as it is threatened, the Pantanal is going through yet another intense series of fires. It is estimated that in the last five years, fires have degraded around 9% of the biome's vegetation. This destruction harms the health of the species that inhabit the Pantanal and those that live outside it. The damage is countless and affects human populations and other animals in the short, medium and long term in various ways. On this subject, Informe ENSP interviewed researchers Sandra Hacon and Marcia Chame, biologists who for decades have been studying issues related to the relationship between health and the environment, including in the Pantanal. 
 
"There are no borders for pollutants," says Sandra, from the Samuel Pessoa Endemic Diseases Department (DENSP/ENSP), commenting on the scope of the health problems caused by fires. Depending on the direction and speed of the winds, other weather conditions and the size of the particles generated by the burning, the pollution can reach municipalities, states and even other countries. "Particles of pollutants can penetrate deep into the lungs and reach the bloodstream, with systemic effects on the human body. These pollutants are responsible for around a third of deaths from strokes, chronic obstructive pulmonary disease, asthma and lung cancer, as well as a quarter of circulatory system diseases," says Sandra Hacon. 

Marcia Chame, coordinator of the Institutional Platform for Biodiversity and Wildlife Health (Pibs/Fiocruz) and researcher at ENSP, also pointed to contamination by atmospheric pollution when she listed the problems faced by those who live in the Pantanal during fires. She also pointed out that environmental contamination also makes water unfit for consumption, increasing the frequency of intestinal infections. In this context, there is also "an increase in skin diseases of unknown etiology", she added. "Smoke and particulate matter in the air generate contamination by mercury and other toxic chemicals. White ash, the result of burning all the organic matter, is also made up of elements that generate contamination, intoxication and degenerative diseases such as cancer, which will only appear later. As the rains arrive, all the ash flows into the corixos, polluting the rivers and bays and killing fish and fry (bait that is the source of income for many communities). There is no more drinking water," says Marcia.

Other damages listed by Marcia Chame affect all aspects of life, from physical and mental health to the economy, amplifying the extent of the damage. "The people of Pantanal suffer the same impacts as animals and plants. They breathe the same air and feel the same heat, they suffer burns when they try to put out the fire and are reached or contaminated by it. They lose their crops,  livestock and pets, fishing, tourism and alternative ways of living. They lose the straw and wood with which they build their houses in the villages. What's more, they lose sight of the places where they were born and live," the researcher lamented. In listing the damages, Marcia further draws attention to the mental health of those affected. "Suicide rates are high. There is depression among the elderly and young people, who do not know where to begin with and lack the resources for a fresh start. Because they are small communities and far from large urban centers, they do not generate national appeal and awareness. They are alone and cut off from hope".

In the same vein, Sandra Hacon emphasizes that fires harm human health disproportionately, since the social determinants of health, such as the location and conditions of housing, level of access to health services and lack of sanitation, tend to exacerbate the effects of exposure to pollutants. "In general, the impacts are more pronounced in populations with lower per capita income, who live in precarious housing conditions," she says. Pollution of the air, water, food and soil affects those exposed in different ways, intensities and magnitudes. "The most vulnerable, such as children under 5, pregnant women, the elderly and people with comorbidities, are the most affected," explains Sandra. 

As they are far from natural areas such as forests and jungles, many people fail to realize that their quality of life and health depends on biodiversity. Contrary to common sense, the tragic consequences caused by the fires in the Pantanal are not restricted to those who inhabit the biome. "The complex network of species that guarantee ecosystem balance is the network that, in turn, ensures the sustainability of life and therefore also of the human species," says Marcia. Natural fires in the Pantanal account for less than 5% of all fires that affect it. In light of this, the biologist is critical, saying that "there has been no significant progress to support actions for the conservation of the Pantanal and therefore to ensure the interdependent health of humans, animals, the ecosystem and the economy". 

Regarding environmental imbalance, Marcia Chame warns of the invasion of species that are exotic to the Pantanal and capable of surviving in such degraded environment. "They settle quickly, giving the feeling that the Pantanal is alive. But this is no longer the Pantanal, it is another, simplified and poorer thing," she laments. The vegetation that makes up biodiversity and serves as food and shelter for animals also suffers, generating an accumulation of negative effects from the fires. "Plants that have not been burnt also suffer from smoke and airborne particles. Just by resisting, they do not flower or bear fruit, which creates more hunger for animals and fewer flowers for pollinators, less seed dispersal, making recovery slow and painful."

In addition to all impacts described by the researchers, there is also concern about the still unknown effects of environmental degradation caused by the fires in the Pantanal. New diseases may emerge and known zoonoses may intensify. "It is still necessary to monitor and understand how fire and smoke can determine the rearrangement of vector and host species that, fleeing from burnt and dry areas, approach human communities and can favor the occurrence of infectious agents that were previously restricted to wildlife cycles. This can lead to the emergence of new diseases or the aggravation of known ones, such as rabies transmitted by bats," Marcia explains.
The Pantanal is home to more than 3,500 species of plants, 300 of fish, 460 of birds, 100 of mammals, 177 of reptiles and 40 of amphibians, as well as an extremely rich invertebrate fauna and little-known microbiota, says Marcia. The researcher explains that, as a floodplain – the world's largest – the region depends on the dynamics of the waters that rise in other biomes and the flying rivers that carry rain formed by the humidity of the Amazon. "It is the dynamics of the floods and ebbs that determine the biodiversity of the Pantanal, which is full of Amazonian and Cerrado species, in addition to its own. It is the water that spreads organic matter and seeds in the areas that will dry out, making them fertile in dry periods."

Everything is connected when it comes to the environment and health. Researcher Marcia Chame points to deforestation in the Amazon as one of the causes of drought and fires in the Pantanal. She also mentions the loss of vegetation on the headwaters and banks of the rivers that feed the biome's hydrological basin. "They are also the result of dams built for irrigation, livestock watering, mining and other human activities, such as the silting up of rivers due to the contribution of crops and the transit of barges," says Marcia Chame. This way, she explains, the floods lose water volume and, therefore, the flooding affects smaller areas. Also, the water drains quickly, so floods are shorter. "Thus, the water table becomes increasingly deeper, extending the droughts," which makes the Pantanal more susceptible to the spread of fire, as the researcher explains. 

The high temperatures, as well as the heatwaves in the Pantanal, marked a climate tragedy in 2020, when more than 37 million vertebrate animals died, as Sandra Hacon recalls. In 2021, a study coordinated by her and carried out in partnership with WWF-Brazil suggested a series of measures for public authorities to prevent and minimize the effects of fires in the Pantanal. According to the researcher, the recommendations were not followed. "One of the most critical factors for environmental control agencies is being able to mitigate forest fires, and the speed with which fires are detected. Some non-governmental organizations, such as SOS Pantanal, which launched the Aracuã system, are managing to monitor fires in real time. Minister Marina Silva has reported that 18 fire starting points have been identified on farms in the Pantanal (MS), and that the Environmental Crimes Law will be applied," says Sandra.

Marcia sums up the seriousness of the problem: "Droughts and fires become consecutive events that feed off and amplify each other, generating impacts beyond the burning during the fire. They have permanent and alarming consequences not only for the Pantanal, but for the entire South American continent, since it is at the center of its multinational territory. There is no perception of this tragedy by the public authorities and no concrete proposals to reverse it. One-off rescue actions will not be enough to protect the Pantanal. The real causes that transform it must be stopped in order to guarantee biodiversity and health".