The Environmental Protection Agency will set a limit on the amount of the chemical perchlorate, as well as other "toxic contaminants," in drinking water, it announced Wednesday.The national regulation on perchlorate will reverse a 2008 decision made by President George W. Bush's administration, the agency said in a statement. It comes after EPA Administrator Lisa Jackson ordered agency scientists to review "the emerging science of perchlorate.""There's going to be a lot of scrutiny of the standard because, again, we are looking at but one of several precursors that can affect iodine uptake in the thyroid," Jackson told CNN's Chief Medical correspondent, Dr. Sanjay Gupta. [Read the full article]

The big issues in the air at this year's World Economic Forum in Davos were privacy and "big data" -- the vast amounts of revealing information we generate when using computers and mobile phones. Pundits have framed the discussion in simplistic terms, as an epic struggle between individual rights and corporate profits.But there is a third way to look at big data -- not just as a commodity ripe for exploitation and abuse, but as a source and multiplier of social good. [Read the full article]

For an injury that is largely invisible, it is no small irony that a new test to detect concussion involves the eyes.The two-minute test, which tracked subtle vision problems in athletes with suspected traumatic brain injury, was a near-perfect gauge of whether a concussion had occurred, according to a new study."Fifty percent of the brain's pathways are devoted to vision," said Dr. Laura Balcer, study co-author, who added that eye movement provides a window into overall brain function. "By doing this test, we can potentially catch a lot of what's going on with overall cognitive function and how impaired an athlete can be following a concussion."The test, called "King-Devick," is based on subtle, constant vibration in the eyes, called saccadic movements, which allow them to focus on specific spots. A problem with the eyes' ability to track and focus suggests impairment involving brain pathways. [Read the full article]

The city that never sleeps is moving closer to becoming the city that never smokes, or at least the city that highly restricts it.Nine years after the Big Apple banned smoking in its restaurants, the New York City Council on Wednesday voted to ban smoking in city parks and on city beaches, Mayor Michael Bloomberg said in a written statement.The council voted 36 to 12 in favor of the ban, much to the chagrin of those who think the government is overstepping its role into its residents' lives."The city is taking it too far. I think it's ridiculous," said 25-year-old New Yorker George Wells as he pressed a lit cigarette to his lips outside the Shops at Columbus Circle.The ban prohibits smoking in all 1,700 city parks and on its 14 miles of beaches, the statement said, and is intended to prevent the harmful effects of secondhand smoke for children. [Read the full article]