A team of ATTO researchers analyzed samples of air collected at ATTO, and said it was “shocking” to discover high levels of so-called “forever chemicals” in this pristine atmosphere.
PFAS, short for perfluoroalkyl and polyfluoroalkyl substances, are a family of human-made chemicals. They include a wide and diverse array of around 5000 toxic chemicals. The term “forever chemicals” comes from the fact that the molecules are extremely stable and do not break down easily. This makes them attractive to make items such as non-stick frying pans, food packaging, coatings on paper, and adhesives. On the flip side, scientists have been able to link PFAS to adverse health effects. Once inhaled can stay inside our bodies for years. This may cause problems including infertility and developmental issues, particularly for pregnant women and their babies. Because of this, this chemical is included in the Stockholm Convention on Persistent Organic Pollutants and was banned in 2020. However, because of their widespread industrial use in prior years, studies find PFAS in the blood of humans and wildlife in remote areas of the globe.
Now Ivan Kourtchev from Coventry University’s Research Centre for Agroecology, Water and Resilience (CAWR) and international colleagues had set out to see if they would be present in the remote Amazon rainforest at ATTO. The international research collaboration is between Coventry University and the Federal University of Parana, the National Institute of Amazonian Research and Federal Institute of Pará in Brazil, the Max Planck Institute for Chemistry in Germany, the University of Graz in Austria, and the University of Cambridge.
They collected their air samples at the 325-metre Amazon Tall Tower Observatory (ATTO), situated in the middle of the rainforest around 150km from Manaus. Kourtchev then analyzed them in his lab at Coventry University using a highly sensitive technique. The samples came from inlets right at the top of the tower and also at tree canopy level at about 42 meters. They found one particular PFAS substance: perfluorooctanoic acid (PFOA). “What was shocking to us was that we saw PFAS at both heights. We didn’t expect to, and especially not to see more at the top of the tower.” If PFAS were to be locally emitted, they should be found lower down the tower. This means PFAS were transported to the site over long distances and have been brought from somewhere. The processes that transported them there were puzzling to the scientists.
Kourtchev said the impact of these chemicals could potentially be severe for the rainforest, its wildlife and also humans. “The Amazon is a place of unique vegetation and wildlife. These forever chemicals can have an impact on that. When our body confuses this chemical with our hormones we can become infertile. If you have some unique animals or vegetation affected, that could stop their reproduction.” In sensitive ecosystems with rare or endangered species, such disruptions can have devastating effects on biodiversity and species survival. PFAS could also adversely affect the health of people living in the rainforest.”
PFAS have been found in places in other remote places such as the coasts of Antarctica. There, scientists theorize that sea spray may have transported the chemicals there. However, as ATTO is situated around 1000 km from the nearest ocean, sea-spray transport of PFAS could not be responsible for the samples collected here. This meant they had to consider other ways the chemicals could have been transported to the ATTO. This site was purposefully built in an area that until recently was mostly unaffected by deforestation or other human interference. Kourtchev said: “One of the other major sources can be firefighting foam used for fires in the rainforest but we were able to rule that out. This meant it must be another source. It could be industrial activities in Manaus but we also can’t rule out burning of domestic waste.”
Further studies are required to pinpoint the sources of these forever chemicals in the Amazon rainforest.
Kourtchev et al. published the study “Occurrence of a “forever chemical” in the atmosphere above pristine Amazon Forest” in the journal Science of the Total Environment. DOI: 10.1016/j.scitotenv.2024.173918
This text is adapted from a press release kindly provided by Coventry University.