title: Health and the urban environment. IX. The concept of the multiplex independent variable.
mesh_terms: D000397:Air Pollution; D003139:Common Cold / Q000453:epidemiology / Q000209:etiology; D004777:Environment; D004782:Environmental Health; D004812:Epidemiologic Methods; D006801:Humans; D009519:New York City; D013223:Statistics as Topic; D013458:Sulfur Dioxide / Q000633:toxicity; D014505:Urban Population; D014887:Weather
chemical_list: D013458:Sulfur Dioxide