title: The 1984 Henry F. Smyth Jr. lecture. When one plus zero is more than one.
mesh_terms: D000395:Air Pollutants, Occupational / Q000633:toxicity*; D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D006168:Guinea Pigs; D012965:Sodium Chloride; D013458:Sulfur Dioxide / Q000633:toxicity; D013464:Sulfuric Acids / Q000633:toxicity; D013997:Time Factors; D014116:Toxicology / Q000379:methods*
chemical_list: D000395:Air Pollutants, Occupational; D013464:Sulfuric Acids; D013458:Sulfur Dioxide; D012965:Sodium Chloride