The new figure was derived from a wide-ranging set of data based on the developmental health of eight-year-olds from about 11 states. U.S. health officials noticed during an effort to quantify the risk of autism that the number had gone up to 57 per cent since 2002.

The vaccine has become sufficiently plentiful, prompting at least 24 states and some other communities to lift restrictions and open distribution to everyone. And some pharmacies are starting to get the vaccine for general distribution

The recession has slashed U.S. output of planet warming gases and puts the country on track to reach President Barack Obama's short-term emissions goal, but cutting the pollution further will take more effort as the economy recovers.

The number of jobless Americans stood at 15.4 million in November, down slightly from October but still more than double the number at the start of the economic slowdown

China’s cabinet yesterday said it will cut output of carbon dioxide per unit of gross domestic product by between 40 percent and 45 percent from 2005.