Table II.

Summary of studies assessing the effects of criteria air pollutants on infant mortality rate

Reference (1)	Location (2)	Population tudied(3)	Aims (4)	Findings (5)
Son et al., 2008 [54]	Seoul, Korea	Firstborn infants in Seoul, Korea, during 1999–2003	To examine the relationship between air pollution and post-neonatal mortality from all causes using both case-crossover and time-series analyses	The risk of post-neonatal infant death from all causes was positively associated with all studied air pollutants except ozone
Woodruff et al., 2008 [55]	U.S. counties with>250,000 residents	Infants born from 1999 to 2002 (n=about 3.5 million births, with 6,639 post-neonatal infant deaths)	To evaluate the relationship between cause-specific post-neonatal infant mortality and chronic early-life exposure to particulate matter and gaseous air pollutants across the United States	PM10 is a risk factor for respiratory-related post-neonatal mortality and ozone may be associated with sudden infant death syndrome
Heinrich et al., 2007 [56]	Review	Studies on the impact of fine particle exposure on infant death, lung function, respiratory symptoms and reproductive outcomes	To review the children's susceptibility to ambient fine particles and characteristics of infant and children which underlie their increased susceptibility to PM	Exposure to PM is strongly and consistently associated with post-neonatal respiratory mortality and less consistently with sudden infant death syndrome
Hajat et al., 2007 [57]	10 major cities of England	Daily time-series data of air pollution and all infant deaths between 1990 and 2000	To investigate the effects of outdoor pollution on infant mortality in the UK	Few associations were observed between infant deaths and most pollutants studied except for SO2
Rinne et al., 2007 [58]	Ecuador	Eighty households in a rural community	To explore the relationship between biomass fuel, infant mortality, and children's respiratory symptoms	A significant trend for higher infant mortality among households that cooked with a greater proportion of biomass fuel was documented
Yang et al., 2006 [59]	Taipei, Taiwan	Infant (27 days – 1 year) mortality data (1994–2000)	To examine the relationship between air pollution exposure and post-neonatal infant mortality	Air pollutants had a non-significant association with the risk of post-neonatal deaths. This weak association might be because of the subtropical climate of the area under study
Woodruff et al., 2006 [60]	California,USA (n=788 infant deaths)	Monitoring data for PM ≤ 2.5 were linked to data of infants born to mothers who lived within 5 miles of a monitor (1999–2000)	To examine the relationship between long-term exposure to fine PM air pollution and post-neonatal infant mortality	Increase in PM2.5 increased post-neonatal mortality and sudden infant death syndrome
Romieu et al., 2004 [61]	Ciudad Juarez, Mexico	Infant mortality and ambient PM10 levels on days before death (1997–2001)	To study short-term PM10 exposure, relating to increased respiratory-related infant mortality, and estimated for poor living conditions	Overall air pollutants did not affect infant mortality but low socioeconomic condition increased this risk. Increase in PM10 increased mortality
Glinianaia et al., 2004 [62]	Review	Epidemiological studies (15 studies included)	Systematic review of an association between particulate air pollution and infant mortality	A strong association of particulate air pollution with some causes of infant death was found
Lipfert et al., 2000 [63]	USA	U.S. birth and death records (1990)	To explore associations between infant mortality and environmental factors, based on spatial relationships	Significantnegative mortality associations were found for SO4(2) without any role for outdoor PM2.5
Loomis et al., 1999 [64]	Mexico City, Mexico	Infant mortality data (1993-1995)	To investigate the association of air pollution and infant mortality by a time-series study	Excess infant mortality was associated with the level of fine particles followed by the levels of nitrogen dioxide and ozone 3 to 5 days before death
Bobak et al., 1992 [65]	Czech Republic	Infant mortality and air pollution data in 46 of the 85 districts (1986–1988)	To assess the ecological associations of air pollution and infant mortality	The strongest effects were seen for the level of total suspended particulates (TSP-10) followed by SO2 level
Duchiade et al., 1992 [66]	Rio de Janeiro, Brazil	Civil Register mortality data (1976–1986)	To study the associations between socioeconomic, climatic, and air pollution variables and the levels of mortality	The mortality rates appeared to be associated with the variations of the log of average pollution