REVIEW / Exposure to the accountancy of suffering

HERE'S a recipe for disaster. Take equal parts of gold-bearing silt and mercury. Mix together well until the mercury has absorbed the gold then strain through a fine fabric to separate the unamalgamated quicksilver. You should be left with a ball of what looks like chrome-plated plasticine. Place this in a crucible and apply a propane torch until all the mercury has evaporated (make sure the room is well ventilated]). Pour remaining gold into a mould and leave until cool to the touch.

As passive smoking goes this is right up there alongside inhaling the fumes from a burning armchair. Indeed the man wielding the blow-torch in Julian Pettifer's report for Assignment (BBC 2) had levels of mercury in his body around 10 times the normal level. He wasn't very happy about this but like around a million other garimpeiros, Brazilian gold prospectors, he had to make a living. Pettifer's programme argued that with mercury flowing into the rivers and atmosphere there was more than just his health at stake.

Oddly this was a classic instance of the difficulty television has in sounding an early warning. Pettifer's statistics were, of necessity, slightly vague. 'Up to 25 per cent of all water that drains of the earth is carried by the Amazon', he said at one point, 'and now sadly much of that global resource is contaminated by mercury.' But how much is 'much of' and how badly contaminated? For every ton of gold extracted it's estimated that two tons of mercury have been lost into the environment. But estimated by who?

Pettifer probably couldn't say because hardly any scientists are working in the area; it is remote, violent, disease-ridden and lawless, a place where men are men and policemen are nervous. Which isn't much of an incentive if you're underpaid and unpopular anyway (very few people want the gold-rush to stop). The Brazilian government is concerned but realistic about the prospect of banning mining that uses mercury. Nor does it seem likely that local politicians will do much. Ivo Lubrinna, a figure straight out of Conrad, is the Secretary for the Environment in one of the mining areas. He is also the Secretary for Mining and has a personal stake in the activities of 250 garimpeiros so he takes a dim view of alarmism about mercury. If I was Pettifer I'd be pitching now for the 'We-told-you-so' follow-up in 1998.

Channel 4's private back room for those with a passion for flagellating dead equines.