As we explained previously, those methane hydrates clogging the uptake pipe need water and low temperatures to form.

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The seawater down there is so cold that when natural gas bubbles out of the well into the water it forms methane hydrates, which clog the uptake pipe.

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The level of concentration in water had a "negligible effect" on people's uptake of the fluoride ion - responsible for increased risk of fractures, they said.

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The testing was done with petrochemicals in water (to replicate oil spills), and the rate of chemical uptake is the highest they've seen.

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