Table 2.

Literature review of ecological studies investigating association between residential proximity to polluted sites and reproductive outcome, order by year of publication

Reference, year,	Design,	Reproductive Outcome	Polluted sites Residential exposure	Confunder factors	Analysis/stratification	Findings
	Country
Berry et al. 1997 [27]	Birth certificate-based study Philadelphia 1961–1985 USA	LBW Preterm birth (<37 weeks)	Landfill site Mother’s exposure defined as living closest to landfill (the only neighborhood adjacent to the landfill and lake) or 1.0 km was extended from the perimeter of the landfill	Potential risk factor: Maternal age, education, parity, number of previous stillbirths, poor parental care, sex of the child	Logistic regression	Among term births (37–44 weeks) Parent living closest to landfill (the neighborhood immediately adjacent to the landfill) had statistically significant higher proportion of LBW and twice the risk of being born preterm
Bhopal et al. 1999 [48]	Ecologic study in Teesside and Sunderland, 1986–1993 United Kingdom	All congenital abnormalities (excluding isolated minor congenital abnormalities), Birth outcomes low birth weight, stillbirth, sex ratio	Petrochimical industries Residential proximity to major steel and petrochemical industries in Teesside divided into three zones based on distance with Sunderland serving as the reference population	–	Unclear	No excess risk of adverse pregnancy outcomes associated with living near major steel and petrochemical industries, exception of low birth weight
Eizaguirr et al. 2000 [25]	Population-based descriptive geographical study during 1982–1989 in Glasgow and nearby areas United Kingdom	All congenital anomalies combined	HWS A 10 km circle centred around former site of factory site designed as study areas and divided into 2 km area containing site and 8 concentric rings around it, each 1 km wide	Carstairs deprivation category	Poisson regressions	Findings suggest that any possible teratogenicity caused by chromium is not apparent. The risk of congenital anomaly is lowest in the area within the first 2 km, and the risk peaks between 2 and 4 km
Fielder et al. 2000 [21]	Ecologic study of population in South Wales, 1983–1996 United Kingdom	All congenital anomalies combined Specific defect Anomalies of the abdominal wall, Birth outcome LBW Spontaneous abortion	Landfill site The exposed population defined as residents living in the five electoral wards within 3 km of the landfill site	Townsend index	Poisson cumulative probabilities were calculated Comparaison between exposed population (within 3 km) and the rest unexposed population	Increased risk for congenital malformations in births among residents living near the site both before opening and after opening There were no consistent differences in proportion of low birth weight infants or spontaneous abortion between the two populations
Elliott et al. 2001 [45]	Ecologic study Great Britain, 1983–1998	All congenital anomalies combined; Specific defects NDT, cardiovascular, and abdominal wall defects; hypospadias and epispadias; surgical correction of hypospadias and epispadias; surgical correction of gastroschisis and exomphalos; Birth ouctome Still births; LBW, VLBW	Landfill site Mother’s exposure defined as residential postcodes within the 2 km buffer zone around site	Year of birth, administrative region, sex of birth, deprivation	Model prediction from poisson regression of data from the reference area to provide standard rates	Small excess risk of congenital anomalies and low and very low birth weight in populations living within 2 km of landfill sites. However, no significant positive association was observe for stillbirth
Baibergenova et al. 2003 [28]	Ecologic study of New York (excluding New York City) (1994–2000) US	VLBW, LBW	PCB-contaminated site Exposure defined as maternal residence at birth in a zip code that contained or was adjacent to a PCB-contaminated site	Sex of the baby, race of the mother, mother’s age, father’s age, mother’s educational level, parents annual per capita income, Medicaid/self-paid births, Maternal weight Single motherhood Maternal smoking	Multiple logistic models Stratification by sex of the baby	Slight association noted for risk of low birth weight in male births and maternal residence in zip code with one or more waste sites contaminated with PCBs. But, no relation between PCB zip codes and very low-birth-weight infants for either sex
Morris et al. 2003 [47]	Ecologic study in Scotland (1982–1997) Great Britain	All congenital anomalies Specific defect. NTD, cardiovascular, and abdominal wall defects; hypospadias and epispadias; surgical correction of hypospadias and epispadias; surgical correction of gastroschisis and exomphalos; Birth outcome. LBW; LBW, Stillbirths	Landfill site Mother exposure defined as residential postcodes within 2 km buffer zone around each site	Year of birth, sex deprivation	Model prediction from poisson regression	No statistically significant excess risks of adverse pregnancy outcomes (LBW, stillbirth, Congenital anomalies) detected in population living within 2 km of a hazardous waste site
Cresswell et al. 2003 [24]	Ecologic study in city of New Castle upon Tyne, 85–99 United Kingdom	Specific defects Chromosomal and non-chromosomal defects	Waste combustion plant Mother’s exposure defined as residence within 3 km of Byker waste combustion plant	ED-level deprivation Not able to adjust for other characteristics	Poisson regressions used to estimate Rate ratios for congenital anomaly	Little evidence of relation between prevalence of congenital malformations and residence near waste combustion plant
Kloppenbor et al. 2005 [26]	Ecological study in Denmark, 1997–2001 Denmark	All congenital anomalies combined Specific defects The nervous or cardiovascular systems in live births	Landfill Three buffer zones: 0–2 (proximal zone), 2–4 (middle zone), and 4–6 km (distal zone) was constructed surrounding waste landfill sites	–	The risk rate (RR) was calculated by dividing the sum of congenital anomaly (or specific defects) by total proximal sum of births	No association found between maternal residential proximity to landfills and all congenital malformations combined or of the nervous system. However, the result noted small excess risk for anomalies of the cardiovascular system
Bentov et al. 2006 [57]	Ecologic study of live births and stillbirths Beer-Sheva subdistrict 1995–2000 Israel	Major congenital malformations combined Specific defects Central nervous system, chromosomal anomalies and other major congenital malformations	Industrial park Distance of localities from regional industrial park and predominant wind direction		Calculation of rateby dividing the number of newborns born with birth defect by the number of deliveries	Residential proximity to industrial park associated with increased rates of major congenital malformations among Bedouin populations
Jarup et al. 2007a [49]	Ecologic study of England and Wales 1989–1998 Great Britain	Specific defects Down syndrome	Landfill site Mother exposure defined as an residential address within 2-km zone of a landfill site	Maternal age Urban–rural status, Carstairs’ index of deprivation	Regression modelling within a Bayesian framework	No excess risk of Down syndrome noted in populations living within 2 km of a landfill site, regardless of site type
Elliott et al. 2009a [11]	Ecologic study in England, 1983–1998 Great Britain	All congenital anomaly combined Specific defects hypospadias and epispadias, cardiovascular defects, NDt, and abdominal wall defects	Landfill site Divided England into a grid of 5 × 5 km squares in which births in each square were classified in terms of its proximity to a landfill site 1 year previously (<2 km, 2+ km) to an index	Carstairs score Presence or absence of a local congenital anomalies register Maternal age % industrial land % urban land	Bayesian hierarchical logistic regression models used with random effects to obtain odds ratios	Significant weak associations observed between risk of all anomalies combined and specific defects and geographic density of only special wastes sites at the level of 5 × 5 grid squares
Castello et al. 2013 [53]	Ecologic study (2004–2008) Spain	VPTB, <33 weeks MPTB, 33–36 weeks VLBW, <1500 g MLBW, 1500–2499 g SGA, birth weight below the national 10th percentile for babies of the same gender and gestational age	Industries site Mothers’ exposure to industrial pollution was estimated by taking the distance from the administrative center of municipality of residence to the pollution source	% adolescent mothers, % mature mothers, % immigrant mothers coming from countries with low income, % mothers who were illiterate mothers or did not complete primary school education, % mothers developing manual work, Population size, habitability index, unemployment rate, average socioeconomic level, % mono-parental families, number of vehicles per household	A Besag, York, and Mollié (BYM) model was fitted for each combination of the 5 outcomes and 24 industrial activity groups	Association between residential proximity to certain types of pollutant industrial facilities and increased risk of some adverse birth outcomes Excess risk of MLBW seemed to be associated with residential proximity to facilities from most of the industrial groups

^aAuthors study specific sites classified by either substance class or reported air emissions of chemicals, or types of contaminants present and media contaminated or with respect to human exposure potential, or contaminated environmental media, and chemical contaminants present