Questo studio analizza la vicinanza residenziale a sorgenti di campi
elettromagnetici ( elettrodotti ) e peso alla nascita.
Gli studi hanno suggerito che l'esposizione residenziale a frequenze estremamente
basse (50 Hz) campi elettromagnetici (ELF-EMF) provenienti da cavi di alta
tensione, linee elettriche aeree, sottostazioni o torri di elettricità sono
associati a ridotto peso alla nascita e può essere associata a nascite con
problemi o addirittura aborti.
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Residential proximity to electromagnetic
field sources and birth weight: Minimizing residual confounding using multiple
imputation and propensity score matching.
- 1Centre for
Occupational and Environmental Health, Institute of Population Health,
Manchester Academic Health Sciences Centre, The University of Manchester,
Oxford Road, Manchester M13 9PL, United Kingdom. Electronic address: frank.devocht@manchester.ac.uk
. - 2Department of
Epidemiology and Biostatistics, Drexel University School of Public Health,
1505 Race St., Philadelphia, PA 19102, USA.
Abstract
Studies have
suggested that residential exposure to extremely low frequency (50 Hz)
electromagnetic fields (ELF-EMF) from high voltage cables, overhead power
lines, electricity substations or towers are associated with reduced birth
weight and may be associated with adverse birth outcomes or even miscarriages.
We previously conducted a study of 140,356 singleton live births between 2004
and 2008 in Northwest England, which suggested that close residential proximity
(≤ 50 m) to ELF-EMF sources was associated with reduced average birth weight of
212 g (95%CI: -395 to -29 g) but not with statistically significant increased
risks for other adverse perinatal outcomes. However, the cohort was limited by
missing data for most potentially confounding variables including maternal
smoking during pregnancy, which was only available for a small subgroup, while
also residual confounding could not be excluded. This study, using the same
cohort, was conducted to minimize the effects of these problems using multiple
imputation to address missing data and propensity score matching to minimize
residual confounding. Missing data were imputed using multiple imputation using
chained equations to generate five datasets. For each dataset 115 exposed women
(residing ≤ 50 m from a residential ELF-EMF source) were propensity score
matched to 1150 unexposed women. After doubly robust confounder adjustment,
close proximity to a residential ELF-EMF source remained associated with a
reduction in birth weight of -116 g (95% confidence interval: -224:-7 g). No
effect was found for proximity ≤ 100 m compared to women living further away.
These results indicate that although the effect size was about half of the
effect previously reported, close maternal residential proximity to sources of
ELF-EMF remained associated with suboptimal fetal growth.
