Extremely hot days are prime for bad air because hydrocarbons evaporate into the air, helping to create ozone.
The Environmental Protection Agency is expected any day now to tighten the standard for how much ozone is safe to breathe, but the level of ozone that scientists say is safe doesn't sit well with industry. The agency decision is sitting at the White House, awaiting approval.
The EPA is redoing the ozone standard set under President George W. Bush. The Bush administration's EPA ignored the advice of its own panel of outside scientific advisers. It set the standard for a healthy level of ozone in the air at 75 parts per billion.
LINDA WERTHEIMER, host: Fans of singer-songwriter Amy Winehouse are mourning the loss of a singular but troubled talent today. The R and B sensation whose career was derailed by drug problems was found dead yesterday in London. She was just 27 years old. NPR's Allison Keyes reports.
ALLISON KEYES: The thing about Amy Winehouse that made people sit up and take notice wasn't just the thick black cat-eye makeup, her figure hugging outfits or the towering black beehive on her head. It was this:
The opening of financial markets in East Asia is causing anxiety in official Washington and beyond. The concern is that a Friday night breakdown in talks between President Obama and House Speaker John Boehner on raising the debt ceiling may have negative repercussions when trading gets under way.
More meetings took place all day Saturday, first at the White House, then at the Capitol, seeking that elusive bipartisan deal.
People pay tribute to victims of the twin attacks before a memorial service at Oslo Cathedral in Norway on Sunday. At least 93 were killed and nearly 100 were wounded in Friday's attacks.
Credit Jan Johannessen / AFP/Getty Images
Mourners gather outside the Domkirken Church in Oslo on Sunday, following a mass for victims of the July 22 government office bombing and shooting spree at a Labour Youth League camp. At least 93 were killed and nearly 100 were wounded in Friday's attacks.
Credit Jeff J Mitchell / Getty Images
Mourners attend a memorial service at Smmerapen Norderhov kirke, following Friday's twin attacks in Oslo, Norway. At least 92 people were killed in the attacks.
The man blamed for attacks on Norway's government headquarters and a youth retreat that left at least 93 dead said he was motivated by a desire to bring about a revolution in Norwegian society, his lawyer said Sunday.
In a manifesto he published online, the suspect says his life began to change during the first Gulf War, when a Muslim friend cheered at reports of missile attacks against U.S. forces.
Campers Mary Church and Jimmy Cong use their sense of smell to detect whether a chemical reaction has taken place.
For some kids, summer camp season means crafts, campfires and sunshine. For teenagers at one Northern California camp, the focus is chemistry.
At Camp Enchanted Hills, about 40 miles north of Napa, the students have something else in common beyond an interest in science: They're all blind or visually impaired. The camp is a rare chance for the kids to compare notes on what it's like to be blind in a sighted world.
Enchanted Hills is owned by Lighthouse for the Blind, a San Francisco nonprofit; the National Federation of the Blind is one of its sponsors.