A chemical used in the manufacture of toilet paper and “perpetual chemicals” have been found in the bodies of killer whales in British Columbia, including the endangered southern killer whale.
Scientists from UBC’s Institute of Oceans and Fisheries, British Columbia’s Ministry of Agriculture and Food, and Fisheries and Oceans Canada analyzed tissue samples from six southern killer whales and six minke whales stranded off the coast of British Columbia from 2006 to 2018. a recent study. They found that chemical contaminants predominated in the killer whales, with a chemical often found in toilet paper being one of the most prevalent in the samples studied, accounting for 46 percent of the total contaminants detected.
The compound, called 4-nonylphenol, or 4NP, is listed as a toxic substance in Canada and can interact with the nervous system and affect cognitive function, the authors said. “This study is a wake-up call. Southerners are threatened with extinction, and it may be that pollutants are contributing to their population decline. We can’t wait to protect this species,” said co-author Dr. Juan José Alava, principal investigator of the department of ocean pollution research at the Institute of Oceans and Fisheries (IOF).
4NP is often used in pulp and paper processing, as well as in soap, detergent and textile industries. It can flow into the ocean through sewage treatment plants and industrial effluents, where it is ingested by smaller organisms and moves up the food chain to reach top predators such as killer whales. It is known as a “contaminant of concern,” or CEC, which is a pollutant found in the environment that is poorly understood and therefore regulated. “Very little is known about both the prevalence and health effects of 4NP because it has been studied in few marine mammals. This study is the first to identify 4NP in killer whales,” said first author Kia Lee, who conducted the research as a student at UBC.
“This investigation is another example of an approach that considers human, animal and environmental health, using killer whales as a case study to better understand the potential effects of these and other compounds on animal and ecosystem health,” said co-author Dr. Stephen Raverty, IOF Adjunct Professor and Veterinary Pathologist for the British American Department of Agriculture and Food.
Just over half of the pollutants identified by the researchers belong to a group of compounds known as “permanent chemicals” because they persist in the environment for long periods of time. They are widely used in food packaging materials, stains and water-repellent fabrics, tableware and fire extinguishers. Many of them are listed as new persistent organic pollutants (POPs). These are toxic substances that enter the environment as a result of human activities and negatively affect the health of people and animals. Many of them are banned in Canada.
The most common contaminant of this group that the researchers found was 7:3-fluorotelomercarboxylic acid, or 7:3 FTCA. There are currently no restrictions on the production and use of 7:3 FTCA, but one of its potential key chemicals is on the list of toxic substances that the European Chemicals Agency proposes to recognize as new POPs under the international agreement, the Stockholm Convention on POPs.
“This compound has not been found in British Columbia before, and it was found in killer whales, which are top predators. This means that the contaminants are making their way through the food system,” says Dr. Alava.
Transmission from mother to fetus
The researchers were also the first to look at the transfer of pollutants from mother to fetus in one Southern couple. They found that all of the pollutants detected were transferred in utero, and 95 percent of 4NP was transferred from mother to fetus.
Governments can help protect southerners and other marine life by stopping the production of chemicals of concern, including 4NP and new POPs such as 7:3 FTCA, and by identifying and eliminating potential sources of marine pollution in the UK and Canada .
It’s not just killer whales that are affected, Dr. Alava said. “We’re mammals, we also eat Pacific salmon, so we need to think about how that might affect our health as well as the other seafood we consume.”
This research was supported by funding from the Department of Fisheries, the UBC Student Research Experience and the Nippon Foundation.