title: Urban, traffic- related particles and lung tumors in urethane treated mice.
abstract: OBJECTIVE
  The present study was designed to evaluate the effects of urban, traffic-related, fine particulate matter (PM2.5) on mice lung tumorigenesis under controlled exposure conditions.
  
  
  METHODS
  Four groups of female Swiss mice were treated with intraperitonial injections of urethane and saline solution. Urethane was used to start the carcinogenesis process. The animals were housed in two chambers receiving filtered and polluted air. In the polluted air chamber, pollutant levels were low. After two months of exposure, the animals were euthanized and lung tumoral nodules were counted.
  
  
  RESULTS
  Saline-treated animals showed no nodules. Urethane-treated animals showed 2.0+2.0 and 4.0+3.0 nodules respectively, in the filtered and non-filtered chambers (p = 0.02), thus showing experimental evidence of increased carcinogenic-induced lung cancer with increasing PM2.5 exposure.
  
  
  CONCLUSIONS
  Our data support the concept that low levels of PM2.5 may increase the risk of developing lung tumors.
authors.affiliation: Department of Pathology, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Fernanda Alves Cangerana
authors.initials: FA
authors.lastname: Pereira
authors.forename: Miriam
authors.initials: M
authors.lastname: Lemos
authors.forename: Thais
authors.initials: T
authors.lastname: Mauad
authors.forename: João Vicente de
authors.initials: JV
authors.lastname: Assunção
authors.forename: Paulo Hilário Nascimento
authors.initials: PH
authors.lastname: Saldiva
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D002273:Carcinogens; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D004195:Disease Models, Animal; D004781:Environmental Exposure / Q000009:adverse effects; D005260:Female; D008175:Lung Neoplasms / Q000139:chemically induced* / Q000473:pathology; D051379:Mice; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis / Q000633:toxicity; D011897:Random Allocation; D012307:Risk Factors; D013997:Time Factors; D014520:Urethane
chemical_list: D000393:Air Pollutants; D002273:Carcinogens; D052638:Particulate Matter; D014520:Urethane