Orca whales are some of the most heavily contaminated marine mammals in the world.
The species are full of chemicals – out “very toxic and carcinogenic” PCBs for the the notorious insecticide DDT.
Now a group of scientists have discovered another chemical of concern – and it’s been linked to toilet paper.
Scientists at the University of British ColumbiaBritish Columbia’s Ministry of Agriculture and Food, and Fisheries and Oceans Canada, found a chemical called 4-nonylphenol (4NP) — along with dozens of other chemicals — in the liver and skeletal tissue of 12 dead Southern and Bigg orcas.
The chemical 4NP belongs to a group of chemicals known as alkyl phenols, which UBC researcher Juan José Alava told Insiders as “very toxic.”
Although Alava and other researchers who spoke to Insider noted that it’s too early to definitively conclude how orcas are affected by 4NP, their discovery raises some concerns.
The amount of 4NP found in killer whales, which tended to be higher in the blood-rich liver tissues, reached an exceptionally high level in one calf.
“These contaminants can fundamentally affect reproduction and development, and we know, based on the weight of evidence, that they affect cognitive function and also the nervous system,” Alava said. “So we’re talking about contamination that’s harmful to the environment and to this orca species.”
Alava said the exact source of 4NP, which affects whales, is unknown, the chemical is mainly found in sewage sludge and sewage treatment plants. It is also used in detergents and cosmetic products.
In addition to 4NP, more than half of the contaminants discovered in the orcas belonged to a category of chemicals known as PFAS — commonly referred to as chemicals for life because they are difficult to break down in the environment.
PFAS can be found in drinking water, FishAnd in trace amounts in human bloodand may increase the risk of diseases such as cancer and liver disease into people.
The study authors noted that this was the first time 7:3 fluorotelomeric carboxylic acid, a type of PFA, had been found in a Pacific Northwest orca. Alava noted that 7:3 FTCA has not previously been found in British Columbia and may indicate the contaminant is moving through food systems.
“You will only be killed by 1,000 cuts”
Although Biggs and Southern Residents both face the possibility of extinction, Southern Residents are theirs Numbers don’t growhave scientists particularly worried.
In addition to the loss of habitat climate changeAnd entanglement The orcas living in the south fight with their food supply in fishing gear.
Overfishing means there is not enough food. And pollutants in the environment mean that foods that are there may well be full of chemicals. Because orcas eat so much, they typically have a higher concentration of chemicals compared to their smaller marine counterparts.
Southerners rely on Chinook salmon to supplement their diet. The discovery of chemicals in their system means Chinook salmon also have contaminants in their system – a warning to people who also consume the salmon.
In addition, a lack of good food impairs orca reproduction, explains Deborah Giles, scientist and principal investigator non-profit wild orcainsiders said.
Giles’ own research found that 69 percent of pregnancies in southern resident orcas were unsuccessful, with 33 percent terminating late in pregnancy or immediately after birth.
“And the females that lose their calves are nutrient poor, which of course helps magnify the effects of chemicals,” Giles said.
Chemicals are also transmitted between mothers and fetuses. The UBC study, which looked at a Southerner named J32, found that any chemicals found in her were transferred to her fetus. J32 died in 2014 while attempting to deliver her fetus, Giles noted.
“They just really get killed by 1000 cuts,” Giles said.
“This is just the tip of the iceberg”
“Too few” orcas have been studied to determine the extent of 4NP contamination in killer whales, the study authors noted, but to obtain even this amount of data on orcas — which are typically studied after they are dead — is an impressive one Task.
Alava told Insiders that with limited access to orca whale organs, he doesn’t think he or the team he worked with will be able to do an autopsy study like this again any time soon.
Due to the lack of data, many questions remain unanswered: Why are some types of certain chemicals less affected than others? What role do these chemicals play in endangering this species? How many more chemicals will researchers find? And which of the dozens of harmful chemicals found in the environment should scientists and regulators focus on when trying to save the species?
Irvin Schultz, a manager of NOAA’s Environmental Chemistry Program, who spoke to Insider about the research, also said more needs to be done to determine their true impact on the species because these specific chemicals have never been studied before.
“It’s definitely more than just tracks,” Schultz said. “So it’s something that gets your attention, and maybe it’s definitely something that you should continue to measure and keep an eye on.”
Schultz, whose lab focuses on measuring other pollutants — like polyaromatic hydrocarbons, which are formed naturally after burning fossil fuels — says it’s also important to remember that orca whales are exposed to so many more pollutants.
“The real value of this study is to provide some data for compounds that haven’t been monitored or measured as often,” Schultz said.
And scientists like Giles continue to pay attention to what other unknown chemicals killer whales may have in their bodies.
“I suspect the more we look, the more we’re going to find in terms of chemicals, man-made chemicals that make their way through the food web and into our apex predators like whales,” Giles said.
“And I think the scary thing for me is that I think that’s just the tip of the iceberg in terms of what we’re going to find.”
This article was originally published by Business Insider.
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