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Killer whales under threat from persistent PCB chemicals, yet emissions continue

PCBs (Polychlorinated Biphenyls) are a group of chemicals which were produced in large quantities by companies such as Monsanto, and were widely used in electrical equipment, sealants and paints. Their production was phased out in the mid 1980’s in Europe, and they are now banned by the global Stockholm convention, as they were found to be toxic and to accumulate in wildlife and people. Many argue this ban should have happened years earlier, and Monsanto has recently been accused of continuing to produce and sell PCBsfor eight years after learning that they posed hazards to public health and the environment“.

Orcas. Source: NOAA, USA

Despite these bans, releases of PCBs to the environment continue because they are present in building products and electrical equipment, though there are processes in place to destroy PCBs in electrical transformers. Emissions from building sealants continue, with little done in many EU countries to address this source.

Once in the environment, PCBs stick around and researchers have found that levels of these chemicals in killer whales (Orca) around Europe are at levels high enough to damage reproduction, with little sign of reduction in recent years. More needs to be done – including by the EU – to prevent ongoing PCB releases from building products and to ensure that all sources are dealt with.

The PCB threat to European killer whales and to humans

The Institute for Zoology and the Zoological Society of London (ZSL) has been running a long term project looking at stranded cetaceans (whales and dolphins), and their study published in 2015 revealed the scale of the problem. This study revealed that European waters are a “hot spot” for PCBs and that though concentrations of PCBs in cetaceans started to decline after the EU ban, they have since stabilised at very high levels in striped dolphins, bottlenose dolphins and killer whales.

The scientists’ analysis was that the levels of PCBs in the cetaceans were high enough to cause reproductive declines and suppress population recovery. They also noted that populations are declining. A small pod of killer whales has been monitored around North West Scotland and Western Ireland waters, for 19 years, but not a single calf has been seen. The pod is facing extinction; killer whale populations are also in serious decline around the rest of Europe.

This research reaffirms the analysis in CHEM Trust’s  2008 publication “Effects of Pollutants on the Reproductive Health of Male Vertebrate Wildlife – Males Under Threat” which summarised the evidence of a correlation between PCB contamination of otters, minks, seals and polar bears, and the decline of the species’ population.

A recent autopsy of a UK killer whale, found dead and entangled in fish lines, revealed that the whale had accumulated 950mg/kg of PCBs in its blubber – more than 100 times the 9mg/kg limit considered as safe. The autopsy also indicated also that the old whale (around 20 years) had never produced a calf. The scientists suggest that it is possible that PCBs had affected the orcas’ brain, because killer whales are clever animals which are almost never found entangled in fish lines.

CHEM Trust’s recent “No Brainer” report reviews the evidence that PCBs are also a threat to human health, including affecting children’s brain development.

Why are PCBs still polluting the environment?

The biggest problem with PCBs is that they are persistent and bioaccumulate:

  • PCBs hardly break down and therefore persist for decades in the natural environment, travelling long distance and polluting the remotest places on earth such as the Artic or the deepest trenches of the ocean.
  • PCBs bioaccumulate in the food chain, building up in fatty tissues, with those animals at the top of the food chain (like killer whales and humans) the most contaminated.

These persistent properties mean that, although their use was phased out in 1979  in the US and in 1980’s in European countries, they are still present in the environment.

However, PCBs are still present in man-made products, though processes have been in place for many years in the EU and around the world to destroy the PCBs in closed applications, such as electrical transformers. However, there is increasing evidence that significant quantities of PCBs are still being released from open uses such as sealants and paints used in the 60s and 70s, and it has been estimated that around 50% of total PCB emissions have come from these ‘open system’ uses.

Scientists in Zurich found that levels of certain ‘indicator’ PCBs (iPCB) were higher in the air outside certain buildings in the city, finding:

“A correlation of iPCB concentrations in air with the number of buildings constructed between 1955 and 1975 in the surrounding areas of the sampling sites… atmospheric iPCB concentrations were measured in the surrounding of a housing complex with PCB-contaminated joint sealants.. annual iPCB emissions of 110-190 g were calculated for this housing complex”

The researchers state “more efforts are required to further eliminate remaining PCB stocks“.

There has also been research done into the presence of PCBs in schools in the US, and the US EPA reports that caulk sealants “put in place between 1950 and 1979 may contain as much as 40 percent PCBs“.

What is being done to deal with PCBs in sealants and other open uses?

PCB controls have tended to focus on closed sources such as transformers, with most countries – and EU level regulations – neglecting open sources like sealants. Given the evidence showing the scale of continuing contamination of the environment by PCBs from such sources, this needs to change.

As the cetacean scientists have stated in another publication in 2016:

“EU regulations to mitigate PCB pollution currently appear insufficient to protect cetacean top predators in the NE Atlantic and Mediterranean Sea.”

“Further steps to reduce PCB inputs into the European marine environment should include stricter controls on disposal of PCBs, e.g. in buildings with sealants containing PCBs”

CHEM Trust supports this call, and has recently mentioned this issue in our response to an EU consultation on the “Chemical, Product, Waste interface”, part of the Circular Economy Action Plan:

“The EU does not currently require management of open uses of PCBs […] There is an urgent need for the EU to review its regulations on PCBs and create new requirements to address open sources of PCBs.”

Our response also points out that the EU treaty states that EU environmental law should be based on the principle that ‘the polluter should pay’ – i.e. that those companies that make money from selling a product (like PCBs) should pay to clear up contamination. This is not happening at the moment.

Michael Warhurst, CHEM Trust Executive Director, said:

“Banning PCBs was a great victory, but it was not enough to adequately protect human health and wildlife as they persist in the environment and are still present in buildings in our cities.

This PCB pollution threatens to remove killer whales from European seas and it is essential that the EU moves rapidly to address PCB-containing sealants and other building materials. Given that the EU is committed to the polluter pays principle, maybe PCB producers such as Monsanto should pay some of the bill?”