Toilet Paper And Forever Chemicals Found In Endangered Killer Whales, Could Lead To Their Population Decline: Study

The researchers discovered that chemical pollutants are prevalent in killer whales. A chemical found in toilet paper accounted for 46 per cent of the total pollutants identified. 

Orcas, with the scientific name Orcinus orca, are the largest of the dolphins and one of the world's most powerful predators, and are immediately recognisable by their distinctive black-and-white colouring. The new study has found harmful chemicals in the bodies of orcas.

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An international team of scientists has found a toxic chemical used in the production of toilet paper, and 'forever chemicals' in the bodies of orcas or killer whales in British Columbia, according to a new study published in the journal Environmental Science & Technology. 

What are killer whales?

Orcas, with the scientific name Orcinus orca, are the largest of the dolphins and one of the world's most powerful predators, and are immediately recognisable by their distinctive black-and-white colouring.

Killer whales are smart and social, make a wide variety of communicative sounds, and use echolocation to communicate and hunt. They make sounds that travel underwater until they encounter objects, then bounce back, revealing the location, size and shape of the objects, according to National Geographic. 

The new study has found harmful chemicals in the bodies of orcas, including the endangered southern resident killer whales. Scientists from the Institute for the Ocean and Fisheries at University of British Columbia, Ocean Canada, and British Columbia Ministry of Agriculture and Food analysed tissue samples from six southern resident killer whales and six Bigg's whales stranded along the coast of British Columbia from 2006 to 2018, as part of the study. 

Bigg's killer whales, also known as Transients, are famous around the world because of their hunting soirees, are mammal hunters and top predators in the sea. 

The researchers discovered that chemical pollutants are prevalent in killer whales. A chemical found in toilet paper accounted for 46 per cent of the total pollutants identified. 

Toxic toilet paper chemical found in whales

The compound found in toilet paper is called 4-nonylphenol or 4NP, and has been listed as a toxic substance in Canada. It can interact with the nervous system and influence cognitive function, according to the authors. 

What is 4NP?

In a statement released by University of British Columbia, Dr Juan José Alava, a co-author on the paper, and principal investigator of the ocean pollution research unit at the Institute for the Oceans and Fisheries (IOF), said the research is a wake-up call, and that the contaminants could be contributing to the population decline of endangered southern resident killer whales. 

Used in soap, detergents, textile, pulp and paper processing, 4NP can leak into the ocean through sewage treatment plants and industrial runoffs, where the waste is ingested by smaller organisms, and moves up the food chain to reach top predators such as killer whales. Known as a 'contaminant of emerging concern', or CEC, 4NP has been studied in few marine mammals. CEC is a term used to describe pollutants found in the environment that are not well-studied or regulated. Kiah Lee, the first author on the paper, said the study is the first to find 4NP in killer whales.

Dr Stephen Raverty, a co-author on the paper, said the investigation is another example of an approach that takes into account the health of people, animals and the environment, using killer whales as a case study to better understand the potential impacts of these and other compounds to animal and ecosystem health. 

What are 'forever chemicals'?

More than half of the pollutants identified as part of the study belong to a group of compounds known as 'forever chemicals'. These compounds are called 'forever chemicals' because they last for a long time in the environment. 

Used widely in food-packaging materials, stain and water-repellent fabrics, cookware and fire extinguishers, many 'forever chemicals' are listed as new Persistent Organic Pollutants (POPs). POPs are toxic substances released into the environment through human activities that adversely affect the health of humans and animals, and many of these are banned in Canada. 

What was the most common POP chemical found in the killer whales?

The most common pollutant from the POP group found by the researchers was 7:3-fluorotelomer carboxylic acid, or 7:3 FTCA. While there are currently no restrictions on the production and use of 7:3 FTCA, one of its potential parent chemicals is on a list of toxic substances proposed to be recognised as new POPs by the European Chemical Agency, under an international agreement called the Stockholm Convention on POPs.

7:3 FTCA found in killer whales for the first time

Dr Alava said the compound has not been found in British Columbia before. For the first time, the compound has been found in killer whales, which are top predators. This means that the contaminants are making their way through the food system, he explained. 

Transfer of pollutants from mother to foetus in killer whales

The researchers, who are also the first to look at the transfer of pollutants from mother to foetus in one southern resident pair, found that all the pollutants identified were transferred in the womb, and 95 per cent of 4NP transferred from mother to foetus.

The authors have suggested that governments should halt production of the chemicals of concern, including 4NP and emerging POPs like 7:3 FTCA, and identify and address potential sources of marine pollution in British Columbia and Canada, to help protect the southern resident killer whales and other marine life. 

Dr Alava said it is not just the killer whales that are affected, but also other mammals, including humans, which consume fish such as Pacific salmon and other seafood.