Poland confirmed on Thursday that a Polish scientist had been arrested in Iran and said it was working to secure his return home, after Tehran announced the arrest of several foreigners that it accused of spying. Iranian state television reported on Wednesday that its Revolutionary Guards had arrested the foreigners for acts that included taking soil samples in restricted areas. The Iranian report identified one of those arrested as a Polish scientist named Maciej Walczak, and another as Giles Whittaker, the second-ranking diplomat at the British embassy. Britain has denied one of its diplomat…