title: 20 years after the winter smog episode 1985--the particle problem then and today.
authors.forename: H Erich
authors.initials: HE
authors.lastname: Wichmann
mesh_terms: D000393:Air Pollutants / Q000592:standards; D002248:Carbon Monoxide / Q000592:standards; D005858:Germany; D009585:Nitrogen Dioxide / Q000592:standards; D010316:Particle Size; D011640:Public Policy; D012905:Smog / Q000517:prevention & control*; D013458:Sulfur Dioxide / Q000592:standards; D013997:Time Factors; D001335:Vehicle Emissions
chemical_list: D000393:Air Pollutants; D012905:Smog; D001335:Vehicle Emissions; D013458:Sulfur Dioxide; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide