Dr David Dixon
Caythorpe, Lincolnshire
• In arguing there can be no undersea oil clouds associated with the spill because “oil has a specific gravity that’s about half that of water. It wants to get to the surface” (BP clashes with scientists, 1 June), Tony Hayward, BP‘s chief executive, displays an alarming ignorance of the properties of his product. True, seawater has a specific gravity of about 1.03g/cubic cm whereas that of crude oil is about 0.8g/cubic cm (less than but not half that of water). But significant fractions of crude oil consist of asphaltenes and other complex substances with specific gravities around 1.4g/cubic cm, ie greater than seawater. These heavier fractions will almost certainly separate and so be retained at depth.
Emeritus professor John Ebdon
University of Sheffield
• The BP spill has become an embarrassment, possibly damaging the British business community as a whole. I’m outraged that BP claims to be doing all it can, when, as a specialist company in natural cotton absorbents that not only absorb spillages of hydrocarbon, but also allow in-situ bioremediation when contamination reaches the shores, I know they are not. We approached BP four years ago. Our efforts and any attempts to follow up proved to be a waste of time, as we encountered only arrogance and lip service. We believe that BP is using polypropylene booms in the Gulf: polypropylene is an oil derivative. There are miles of cellulose booms available: why is BP ignoring the more natural approach? Worse: our HQ and manufacturing plant is located three hours’ drive from the contaminated areas.
Antonella Cane
Director, Wild Berry Environment
• Gordon Brown agonised over what it meant to be British. Now, British Petroleum and British Airways have shown unambiguously what British stands for.
Robert Wootton
Llanbadarn Fawr, Dyfed