https://www.theguardian.com/environment/2024/feb/24/abandoned-oil-gas-pipelines-poison-pollution-risk-north-sea-scientists

Decaying oil and gas pipelines left to fall apart in the North Sea could release large volumes of poisons such as mercury, radioactive lead and polonium-210, notorious for its part in the poisoning of Russian defector Alexander Litvinenko, scientists are warning.

Mercury, an extremely toxic element, occurs naturally in oil and gas. It sticks to the inside of pipelines and builds up over time, being released into the sea when the pipeline corrodes.

Some methylmercury, the most toxic form of the metal, is released by the pipelines although other forms can be converted into it. The international Minamata convention on mercury states that high levels in dolphins, whales and seals can lead to “reproductive failure, behavioural changes and even death”. Seabirds and large predatory fish such as tuna and swordfish are also particularly vulnerable.

Lhiam Paton, a researcher from the Institute for Analytical Chemistry at the University of Graz who has raised the alarm over the mercury pollution, told the Guardian and Watershed Investigations that “even a small increase in mercury levels in the sea will have a dramatic impact on the animals at the top of the food web”.

There are about 27,000km (16,800 miles) of gas pipelines in the North Sea, and scientists predict the amount of the metal in the sea could increase anywhere from 3% up to 160% from existing levels. In some countries, such as Australia, companies are required to remove them when the oil well stops operating. But in the North Sea companies are allowed to leave them to rot away.

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https://www.theguardian.com/environment/2024/feb/24/abandoned-oil-gas-pipelines-poison-pollution-risk-north-sea-scientists