German scientists design an inhaler that protects lungs against air pollution and expect it to be available as an inexpensive, over-the-counter product this year. Roselle Chen reports.
01:20
01:41
02:13
01:42
02:12
01:57
02:39
03:05
01:27
01:26
02:19
02:13
02:03
02:02
01:27
01:15
03:37
02:39
01:44
02:46