title: Air pollution and human fertility rates.
abstract: BACKGROUND
  Some reports have suggested effects of air pollution on semen quality and success rates of in vitro fertilization (IVF) in humans and lower fertility rates in mice. However, no studies have evaluated the impact of air pollution on human fertility rates.
  
  
  OBJECTIVE
  We assessed the association between traffic related air pollution and fertility rates in humans in Barcelona, Spain (2011-2012). We hypothesized that higher air pollution levels would be associated with lower fertility rates.
  
  
  METHODS
  We calculated the general fertility rate which is the number of live births per 1000 women between the ages of 15 and 44 years per census tract. We used land use regression (LUR) modeling to estimate the air pollution concentrations (particulate matter, NO2/NOx) per census tract. We used Besag-York-Mollié models to quantify the relationship between air pollution and fertility rates with adjustment for a number of potential confounders such as maternal age and area level socio-economic status.
  
  
  RESULTS
  We found a statistically significant reduction of fertility rates with an increase in traffic related air pollution levels, particularly for the coarse fraction of particulate matter (IRR=0.87 95% CI 0.82, 0.94 per IQR).
  
  
  CONCLUSIONS
  This is the first study in humans to show an association between reduced fertility rates and higher traffic related air pollution levels.
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Spain; UPF, Spain. Electronic address: mnieuwenhuijsen@creal.cat.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Nieuwenhuijsen
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Spain; UPF, Spain.
authors.forename: Xavier
authors.initials: X
authors.lastname: Basagaña
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Spain; UPF, Spain.
authors.forename: Payam
authors.initials: P
authors.lastname: Dadvand
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Spain; UPF, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Martinez
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; CIBER Epidemiología y Salud Pública (CIBERESP), Spain; UPF, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Cirach
authors.affiliation: Institute for Risk Assessment Sciences, Division Environmental Epidemiology, Utrecht University, Utrecht, The Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: Beelen
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Centre for Research in Epidemiology and Population Health (CESP), U1018, Respiratory and Environmental Epidemiology Team, INSERM, Villejuif, France; UMRS 1018, Université Paris Sud, Villejuif, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Jacquemin
mesh_terms: D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D000397:Air Pollution; D001723:Birth Rate; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D013030:Spain / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000393:Air Pollutants
keywords: Air pollution; Epidemiology; Fertility; Infertility