title: Problems in ecological studies.
authors.forename: B L
authors.initials: BL
authors.lastname: Cohen
mesh_terms: D004463:Ecology; D004781:Environmental Exposure / Q000009:adverse effects*; D004812:Epidemiologic Methods; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality; D009381:Neoplasms, Radiation-Induced / Q000401:mortality; D011886:Radon / Q000009:adverse effects
chemical_list: D011886:Radon