Oil depot explosion, long term health risks

Reports of an explosion that yesterday tore through an oil storage terminal in Hertfordshire, UK, could be overlooking significant health risks, says a leading combustion engineer. 

There were 36 reported casualties, only two of which were serious, and no reported deaths following the blast at the Buncefield terminal. But that isn’t the end of the story, said Clifford Jones at the University of Aberdeen.

People living near the terminal have been advised to stay indoors and keep windows closed, but risks associated with the fumes are being played down by health officials.

’One point they overlook in smoke is polyaromatic hydrocarbons,’ said Jones, whose research on fuels and combustion is focused on hydrocarbon process safety.  ’Polyaromatic hydrocarbons are the precursor to smoke: where you’ve got smoke you’ve got those, it’s why smokers die of lung cancer,’ said Jones.

’I would expect there’ll be a blip in the asthma and bronchitis deaths almost immediately, and a blip in the lung cancer deaths a few decades down the track cannot be ruled out,’ he told Chemistry World. 

Sulfur dioxide also poses a significant threat, says Jones. The Buncefield terminal holds a range of products, notably heavier fractions that have higher sulfur content. ’So there must’ve been a fair amount of sulfur dioxide as well.’ Sulfur dioxide is repeatedly linked to asthma and bronchitis deaths. 

The terminal, a joint venture between Total (60 per cent) and Texaco (40 per cent), receives, stores and distributes petroleum products from the Total Lindsey oil refinery on the south bank of the Humber estuary.

Experts will be tracking the source of the explosion, looking at the pattern of damage caused as 20 fuel tanks went up in smoke. The degree and timing of damage caused to surrounding buildings - windows broken, plaster ripped from ceilings etc - could be followed retrospectively to indicate how much hydrocarbon exploded on the site at what time. 

Windows were blown out two miles from the depot. Such damage is typically the result of an additional 0.01 of one atmosphere, says Jones. Major structural damage is the result of an additional 0.1 of one atmosphere.

’That could lead to the identification of which tank had the initial leakage,’ said Jones, who suspects the explosion was caused by a gasoline leak. Similarly, he says, each tank will have a temperature record based on thermocouple traces, which could be used to map the sequence of events as they occurred yesterday morning.

It could take years to confirm the source, said Jones: a combination of scientific analysis to find out what happened, followed by what is bound to be a lengthy litigation process. Bea Perks