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Ambient air pollution and neurotoxicity on brain structure: Evidence from women's health initiative memory study
Author(s) -
Chen JiuChiuan,
Wang Xinhui,
Wellenius Gregory A.,
Serre Marc L.,
Driscoll Ira,
Casanova Ramon,
McArdle John J.,
Manson JoAnn E.,
Chui Helena C.,
Espeland Mark A.
Publication year - 2015
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.24460
Subject(s) - brain size , confounding , interquartile range , confidence interval , medicine , white matter , corpus callosum , magnetic resonance imaging , pathology , radiology
Objective The aim of this study was to examine the putative adverse effects of ambient fine particulate matter (PM 2.5 : PM with aerodynamic diameters <2.5μm) on brain volumes in older women. Methods We conducted a prospective study of 1,403 community‐dwelling older women without dementia enrolled in the Women's Health Initiative Memory Study, 1996–1998. Structural brain magnetic resonance imaging scans were performed at the age of 71–89 years in 2005–2006 to obtain volumetric measures of gray matter (GM) and normal‐appearing white matter (WM). Given residential histories and air monitoring data, we used a spatiotemporal model to estimate cumulative PM 2.5 exposure in 1999–2006. Multiple linear regression was employed to evaluate the associations between PM 2.5 and brain volumes, adjusting for intracranial volumes and potential confounders. Results Older women with greater PM 2.5 exposures had significantly smaller WM, but not GM, volumes, independent of geographical region, demographics, socioeconomic status, lifestyles, and clinical characteristics, including cardiovascular risk factors. For each interquartile increment (3.49μg/m 3 ) of cumulative PM 2.5 exposure, the average WM volume (WMV; 95% confidence interval) was 6.23cm 3 (3.72–8.74) smaller in the total brain and 4.47cm 3 (2.27–6.67) lower in the association areas, equivalent to 1 to 2 years of brain aging. The adverse PM 2.5 effects on smaller WMVs were present in frontal and temporal lobes and corpus callosum (all p values <0.01). Hippocampal volumes did not differ by PM 2.5 exposure. Interpretation PM 2.5 exposure may contribute to WM loss in older women. Future studies are needed to determine whether exposures result in myelination disturbance, disruption of axonal integrity, damages to oligodendrocytes, or other WM neuropathologies. Ann Neurol 2015;78:466–476