[Cleansing of water and air].
D000397:Air Pollution / Q000517:prevention & control*; D004777:Environment; D004781:Environmental Exposure; D006920:Hygiene; D009787:Occupational Medicine; D011634:Public Health; D012722:Sewage; D013242:Sterilization; D013557:Switzerland; D014876:Water Pollution / Q000517:prevention & control*
D012722:Sewage
Reinhaltung von Wasser und Luft.