Reuters: Ash particles from Iceland’s still-erupting volcano remain high in the atmosphere and do not pose a health risk so far to people in Europe, the World Health Organization said on Tuesday. Toning down its guidance from Friday, when it said the ash cloud that has grounded flights could be “very dangerous” for those with asthma and respiratory problems, the WHO said there was no cause for public health alarm so far. “There are no effects on health at the moment, except in the …