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Association Between Ambient Air Pollution and Amyloid Positron Emission Tomography Positivity in Older Adults With Cognitive Impairment
Iaccarino L, La Joie R, Lesman-Segev OH, Lee E, Hanna L, Allen IE, Hillner BE, Siegel BA et al.. JAMA neurology, 2021-02-01
Topic: Amyloid, tau and blood-test diagnosis
Importance Amyloid-β (Aβ) deposition is a feature of Alzheimer disease (AD) and may be promoted by exogenous factors, such as ambient air quality. Objective To examine the association between the likelihood of amyloid positron emission tomography (PET) scan positivity and ambient air quality in individuals with cognitive impairment. Design, setting, and participants This cross-sectional study used data from the Imaging Dementia-Evidence for Amyloid Scanning Study, which included more than 18 000 US participants with cognitive impairment who received an amyloid PET scan with 1 of 3 Aβ tracers (fluorine 18 [18F]-labeled florbetapir, 18F-labeled florbetaben, or 18F-labeled flutemetamol) between February 16, 2016, and January 10, 2018. A sample of older adults with mild cognitive impairment (MCI) or dementia was selected. Exposures Air pollution was estimated at the patient residence using predicted fine particulate matter (PM2.5) and ground-level ozone (O3) concentrations from the Environmental Protection Agency Downscaler model. Air quality was estimated at 2002 to 2003 (early, or approximately 14 [range, 13-15] years before amyloid PET scan) and 2015 to 2016 (late, or approximately 1 [range, 0-2] years before amyloid PET scan). Main outcomes and measures Primary outcome measure was the association between air pollution and the likelihood of amyloid PET scan positivity, which was measured as odds ratios (ORs) and marginal effects, adjusting for demographic, lifestyle, and socioeconomic factors and medical comorbidities, including respiratory, cardiovascular, cerebrovascular, psychiatric, and neurological conditions. Results The data set included 18 178 patients, of which 10 991 (60.5%) had MCI and 7187 (39.5%) had dementia (mean [SD] age, 75.8 [6.3] years; 9333 women [51.3%]). Living in areas with higher estimated biennial PM2.5 concentrations in 2002 to 2003 was associated with a higher likelihood of amyloid PET scan positivity (adjusted OR, 1.10; 95% CI, 1.05-1.15; z score = 3.93; false discovery rate [FDR]-corrected P Conclusions and relevance This study found that higher PM2.5 concentrations appeared to be associated with brain Aβ plaques. These findings suggest the need to consider airborne toxic pollutants associated with Aβ pathology in public health policy decisions and to inform individual lifetime risk of developing AD and dementia.
Key findings
- Results The data set included 18 178 patients, of which 10 991 (60.5%) had MCI and 7187 (39.5%) had dementia (mean [SD] age, 75.8 [6.3] years; 9333 women [51.3%]).
- Living in areas with higher estimated biennial PM2.5 concentrations in 2002 to 2003 was associated with a higher likelihood of amyloid PET scan positivity (adjusted OR, 1.10; 95% CI, 1.05-1.15; z score = 3.93; false discovery rate [FDR]-corrected P < .001; per 4-μg/m3 increments).
- These findings suggest the need to consider airborne toxic pollutants associated with Aβ pathology in public health policy decisions and to inform individual lifetime risk of developing AD and dementia.
Why it matters
In this cross-sectional study, living in areas with higher estimated fine particulate matter concentrations in 2002 to 2003 was associated with a higher likelihood of a positive amyloid PET scan. It suggests a possible link between air pollution and amyloid deposition but does not test any treatment, cure, or prevention.
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Study details
- Study designcross-sectional
- Participants18
- Effect size60.5%; 39.5%; 51.3%
- Evidence strengthLow
How this study scored 62/100
Published in a leading specialty journal, and it is a snapshot of people at one point in time. Scored zero for randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (JAMA neurology) |
| Journal's citation record | 2 / 4 | JAMA Neurology: journal h-index 235 (OpenAlex, 2026-10-29) |
| Study design | 4 / 12 | A snapshot of people at one point in time |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 3 / 5 | 2021 — within 6 year(s) of the newest study here |
| Sample size | 1 / 4 | 18 participants |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 124 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 17.7 citations a year over 7 year(s) since 2021 |
| Impact for its field and year | 4 / 6 | Cited 9.1× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 3 other studies in this library |
| Still being cited | 3 / 4 | Cited 66 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Gil D. Rabinovici: h-index 116 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Washington University in St. Louis: institution h-index 1,962 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 8 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 33252608) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 62 / 100 | — |
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Read the original
- DOI: 10.1001/jamaneurol.2020.3962
- PubMed: 33252608
- Original source →
- Free full text: PubMed Central →
Full text: free to read — PubMed Central lists this copy as free to read: the link above (checked 10 Oct 2026).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Iaccarino, L., La Joie, R., Lesman-Segev, O. H., Lee, E., Hanna, L., Allen, I. E., et al. (2021). Association Between Ambient Air Pollution and Amyloid Positron Emission Tomography Positivity in Older Adults With Cognitive Impairment. JAMA neurology. https://doi.org/10.1001/jamaneurol.2020.3962
Vancouver
Iaccarino L, La Joie R, Lesman-Segev OH, Lee E, Hanna L, Allen IE, et al. Association Between Ambient Air Pollution and Amyloid Positron Emission Tomography Positivity in Older Adults With Cognitive Impairment. JAMA neurology. 2021. doi:10.1001/jamaneurol.2020.3962. PMID: 33252608.
BibTeX
@article{iaccarino2021-33252608,
author = {Iaccarino, L. and La Joie, R. and Lesman-Segev, O. H. and Lee, E. and Hanna, L. and Allen, I. E. and Hillner, B. E. and Siegel, B. A. and others},
title = {{Association Between Ambient Air Pollution and Amyloid Positron Emission Tomography Positivity in Older Adults With Cognitive Impairment}},
journal = {JAMA neurology},
year = {2021},
doi = {10.1001/jamaneurol.2020.3962},
pmid = {33252608},
url = {https://doi.org/10.1001/jamaneurol.2020.3962}
}
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