It has always surprised me how much some environmental groups go on about mercury in fish - often to the detriment of talking about the sustainability of fish themselves.  It is undoubtedly true that mercury is the most toxic non-radioactive metal on Earth and the contamination of fish is to be deplored.  Health advice on both sides of the Atlantic is virtually identical: women of child-bearing age are advised not to eat large predatory fish such as sharks and swordfish because of the high level of mercury they accumulate from eating other fish.  Yet the number of headlines in North America about mercury in fish is far greater than the number in Europe. Perhaps the idea that "my body's a temple" is stronger over there. Either way, it seems curious that if the Americans are so worried about it, they should have missed until now what I wrote up in the Sunday Times at the weekend, which is that the amount of mercury accumulated and emitted into the air and water by the global oil and gas industry has been totally overlooked.

The NGOs that are fondest of campaigning about mercury tell us that the biggest sources of mercury in fish, apart from the natural seams which lie under the sea in certain parts of the world, are coal fired power stations and chlorine plants.  Coal-fired power stations collectively emit an estimated  2000 tons of mercury a year.  That's a lot, when you consider that a gram of mercury in a ten acre lake is enough to have a health advisory issued about its fish in the US.  Why is it then that no one seems to have considered or properly inventoried the amount of mercury emitted by the other forms of fossil fuel, oil and gas?  Figures I have seen show that the amount of mercury collected by oil and gas rigs in South East Asia, where natural mercury levels are high and where consumers are aware of the problem of mercury and do not want it in their fuel, can be as much as ten tons per rig per year.  More typically, oil and gas rigs produce around 1.5 to 2 tons of mercury per year. So it is not inconceivable that the amount of mercury produced by the hundreds of oil and gas rigs at sea exceeds the amount produced by what was thought to be the largest producer, the world's coal-fired power stations.

Where does all this mercury go?  Well, I wish I knew and so do officials from the United Nations Environment Programme who have been trying to draw up an inventory of mercury emissions.  Even in rigs where the mercury is painstakingly collected, because it can interfere with aluminium in refinery pipes, it is estimated that up to 80 per cent of it can escape as gas.  We do not have good figures on where the mercury goes and the oil industry doesn't seem particularly interested in producing them.  There are several ironies here. One is that we are told that we in Europe and the US have such high
environmental standards, yet it is in South East Asia that they actually fit mercury scrubbers to remove the heavy metal from fuel, whereas I am aware of only one British rig with mercury scrubbing technology in the North Sea and none in US waters. Now you may say naturally-occurring mercury levels are higher in South East Asia than in some other parts of the world.  Well, they are, but what of the rigs in areas where the levels are lower but still significant?  What is the reason they are not fitting mercury abatement technology?  Is it because the levels are vanishingly low (unlikely) or because of
cost?  And why is it that the oil and gas industry is the only industry which is not part of the forthcoming global treaty to reduce mercury emissions?  The US Environmental Protection Agency pointed out the lack of data on mercury emissions from oil and gas installations in 2001.  You would have thought something might have happened by then, a comprehensive assessment or report to make good the deficiency of our knowledge, perhaps.  But no.  Nothing.  Could that possibly be because one of the most flagrantly pro-oil and gas Administrations, the Bush Administration, was in power for most of the time since then?

The oil and gas industry has kept its dirty secret quiet for long enough.  It's time it fessed up about what it is doing like everyone else.