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 |