title: Impact of air pollution and temperature on adverse birth outcomes: Madrid, 2001-2009.
abstract: OBJECTIVE
  Low birth weight (<2500 g) (LBW), premature birth (<37 weeks of gestation) (PB), and late foetal death (<24 h of life) (LFD) are causes of perinatal morbi-mortality, with short- and long-term social and economic health impacts. This study sought to identify gestational windows of susceptibility during pregnancy and to analyse and quantify the impact of different air pollutants, noise and temperature on the adverse birth outcomes.
  
  
  METHODS
  Time-series study to assess the impact of mean daily PM2.5, NO2and O3(μg/m3), mean daily diurnal (Leqd) and nocturnal (Leqn) noise levels (dB(A)), maximum and minimum daily temperatures (°C) on the number of births with LBW, PB or LFD in Madrid across the period 2001-2009. We controlled for linear trend, seasonality and autoregression. Poisson regression models were fitted for quantification of the results. The final models were expressed as relative risk (RR) and population attributable risk (PAR).
  
  
  RESULTS
  Leqd was observed to have the following impacts in LBW: at onset of gestation, in the second trimester and in the week of birth itself. NO2had an impact in the second trimester. In the case of PB, the following: Leqd in the second trimester, Leqn in the week before birth and PM2.5in the second trimester. In the case of LFD, impacts were observed for both PM2.5in the third trimester, and minimum temperature. O3proved significant in the first trimester for LBW and PB, and in the second trimester for LFD.
  
  
  CONCLUSIONS
  Pollutants concentrations, noise and temperature influenced the weekly average of new-borns with LBW, PB and LFD in Madrid. Special note should be taken of the effect of diurnal noise on LBW across the entire pregnancy. The exposure of pregnant population to the environmental factors analysed should therefore be controlled with a view to reducing perinatal morbi-mortality.
authors: National School of Public Health, Carlos III Institute of Health, Madrid, Spain; University of Salamanca Health Care Complex (Complejo Asistencial Universitario de Salamanca/CAUSA), Salamanca, Spain.
authors: Virginia
authors: V
authors: Arroyo
authors: National School of Public Health, Carlos III Institute of Health, Madrid, Spain.
authors: Julio
authors: J
authors: Díaz
authors: National School of Public Health, Carlos III Institute of Health, Madrid, Spain.
authors: Rocío
authors: R
authors: Carmona
authors: National School of Public Health, Carlos III Institute of Health, Madrid, Spain.
authors: Cristina
authors: C
authors: Ortiz
authors: National School of Public Health, Carlos III Institute of Health, Madrid, Spain. Electronic address: clinares@isciii.es.
authors: Cristina
authors: C
authors: Linares
mesh_terms: D000393:Air Pollutants / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D047108:Embryonic Development; D005260:Female; D006801:Humans; D009622:Noise; D011247:Pregnancy; D011256:Pregnancy Outcome; D012307:Risk Factors; D013030:Spain; D013696:Temperature
chemical_list: D000393:Air Pollutants
keywords: Air pollution; Environmental factors; Low birth weight; Preterm births