National Public Radio: British oil giant BP continued to dump chemicals onto a massive oil slick in the Gulf of Mexico on Tuesday in an effort to break up the sheen and minimize damage to coastal communities. BP executive Doug Suttles said he’s not certain whether the chemicals being poured directly on the oil are slowing the leak from a blown-out well a mile underwater. But he said that if the technique is working, the slick should appear smaller when the company does flyovers. An expected improvement in …