The particularity of these polluting compounds – explains Cristobal Galbán – is that they were used a long time ago and nowadays are prohibited, but they are characterized by  their degradation rate in the environment which is very low and can be transferred.

“The Antarctic Ocean it is a carbon drain especially during the summer.” This is explained by Cristobal Galbán from Mayor University, who is developing a study on Persistent Organic Pollutants (COP, acronyn in Spanish – POP, acronym in English).

The basic hypothesis of the study is that the phytoplankton that grows in the water column is a crucial component of the process known as  “biological pump,” that is when the phytoplankton produce fixed CO2 and transports carbon into the sediments. This phenomenon is very important to understand the biogeochemical cycle of POPs, because these compounds are hydrophobic and will tend to bind to the organic material that is transported to the sediments as a result of the biological pump.

They can reach the white continent from long distances by oceanic or atmospheric currents, or even by migratory animals. “Influence of the biological pump on the biogeochemistry of persistent organic pollutants in pristine RT 1217 environments”, that is the name of the project from the researcher Galbán, who together with his team are part of the Antarctic Scientific Expedition (ECA 56), organized by the Chilean Antarctic Institute (INACH).

At the base “Prof. Julio Escudero”, the journalistic team from INACH talked about the project, whose main objective is to study the biogeochemical cycle of POPs in Antarctica. Until now, it is known that the surface of the Antarctic Ocean is a sink for these pollutants, nonetheless, it is unknown what process occurs in the water column, since so far, they had been carried out indirectly.

“The particularity of these polluting compounds is that they were used a long time ago and that they are currently banned, but they are characterized in that their degradation rate in the environment is very low and can be transferred between different arrays. Little is known about the transfer of POPs along the trophic chain in the Southern Ocean, where krill plays an important role as an ecological node between primary producers and consumers, says Galbán.

According to INACH’s information, the environmental biologist points out that these pollutants would come mainly from South America, pointing out that today are reports of lakes and rivers in the country in where these types of pollutants have been found and that have remained there for a long time. The vast majority of these are pesticides that were once used in agriculture, such as lindane or DDT, which even been used in humans to fight lice.

“In studies that we have been able to carry out in the Arctic, we could observe that the emissions came from Canada or the Northern United States. Some contaminants were transported in a day or two to the pole, and others took seven days. These permanent pollutants that we are pursuing have not been used in Antarctica. POPs are used at medium latitudes and at higher temperatures, and when a layer is released it remains in the air and in the stratosphere with a very low degradability” adds Galbán. 

“We take these samples because we know that they are in the air and particles. We take samples of air and particles by polyurethane foams and a special filter with the size of a letter. In this way the air passes through the filter and retains the particles and subsequently we take a sample of air without particles taken in the polyurethane foam; So far this methodology has been useful for us. Our work into water follows the same principle. The water is passed through filters to retain the suspended particles of the surface (in the first 5 meters) and then the water is passed, without particles, through a stainless-steel column that contain a resin that retains the contaminants,” says Galbán.

The Antarctic researcher underlined to INACH’s journalistic team that has carried out other experiments where the pollutants directly affect phytoplankton, decreasing and changing species diversity. “We ask ourselves for this project, what happens when there is a phytoplankton bloom? Does krill suffer with these contaminants? These are questions that we will try to solve with the results of this project. Being able to conduct studies in Antarctica represents a logistical challenge but also a substantial opportunity since Antarctica plays an accumulating role since pollutants are retained, because they are semi-volatile, but when they reach colder temperatures they condense”

Other Antarctic works have analyzed penguin feces and realized that there was some relationship between some hormonal conditions and the concentration of these organic pollutants. Galbán points out that is difficult to know if it causes long-term damage in species such as penguins, because it requires working with animals and follow-up them. Finally, Galbán indicates that even with the samples he is currently taking, they even could reveal if there is influence from the fires that are raging in Australia, because satellite data shows that there are particles that have been transported through the air masses