U.S. Customs officers stationed at the UPS hub in Louisville, Ky., continue to intercept an increasing number of imported "bath salts" designer drugs, the agency said. Field personnel are working closely with chemists at Customs and Border Protection labs to test samples and detect emerging trends related to the synthetic drugs. Bath salts can contain the controlled substances MDPV, mephedrone and methylone, or a synthetic derivative of the psychoac...