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Possible association between PM2.5 and neurodegenerative diseases: A systematic review
Cristaldi A, Fiore M, Oliveri Conti G, Pulvirenti E, Favara C, Grasso A, Copat C, Ferrante M.. Environmental research, 2021-12-31
Topic: Brain proteins, microglia and lab models
Air pollution is one of the most serious environmental problems that afflict our planet and one of the greatest risk factors for human health. In particular, PM 2.5 is able to cross the blood-alveolar and blood-brain barriers, thus increasing the onset of respiratory, cardiovascular and neurodegenerative diseases. Neurodegenerative disease is a progressive neuronal dysfunction that leads to neuronal lesions in both structure and function, and includes several diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), vascular dementia (VaD), multiple sclerosis (MS), and others. We carried out a systematic review using PRISMA approach to investigate on the possible association between exposure to PM 2.5 and neurodegenerative diseases. The international databases (PubMed, Science Direct, Web of Sciences) were used to find published studies on the topic. The search period was between January 2011 and June 2021. About 2000 full research articles were selected, and finally, we included 20 full-research articles. Selected studies have highlighted how PM 2.5 exposure can be associated with the onset of neurodegenerative diseases (AD, PD, MS, VaD). This association depends not only on age, PM 2.5 levels and exposure time, but also on exposure to other air pollutants, proximity to areas with high vehicular traffic, and the presence of comorbidities. Exposure to PM 2.5 promotes neuroinflammation processes, because through breathing the particles can reach the nasal epithelial mucosa and transferred to the brain through the olfactory bulb. Furthermore, exposure to PM 2.5 has been associated with an increased expression of markers of neurodegenerative diseases (e.g. alpha-synuclein or beta-amyloid), which can contribute to the etiopathogenesis of neurodegenerative diseases. Although many studies have revealed the pathological relationship between PM 2.5 exposure and cognitive impairment, the potential cellular and molecular mechanisms of PM 2.5 leading to neurodegenerative disease remain not entirely clear, and then, further studies need to be carried out on the topic.
Key findings
- Selected studies have highlighted how PM 2.5 exposure can be associated with the onset of neurodegenerative diseases (AD, PD, MS, VaD).
- Furthermore, exposure to PM 2.5 has been associated with an increased expression of markers of neurodegenerative diseases (e.g. alpha-synuclein or beta-amyloid), which can contribute to the etiopathogenesis of neurodegenerative diseases.
- Although many studies have revealed the pathological relationship between PM 2.5 exposure and cognitive impairment, the potential cellular and molecular mechanisms of PM 2.5 leading to neurodegenerative disease remain not entirely clear, and then, further studies need to be carried out on the topic.
Why it matters
This review of 20 studies reports that exposure to PM 2.5, the fine particles in air pollution, has been associated with the onset of neurodegenerative diseases including Alzheimer's, Parkinson's, multiple sclerosis and vascular dementia. The authors describe how particles may reach the brain through the nose and promote neuroinflammation, but say the exact mechanisms remain unclear and more research is needed.
Study details
- Study designsystematic review
- Participants20
- Evidence strengthHigh
How this study scored 62/100
Published in a peer-reviewed journal, and it is a systematic review of all the studies on the question. Scored zero for effect reported because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Environmental research) |
| Journal's citation record | 3 / 4 | Environmental Research: journal h-index 259 (OpenAlex, 2026-10-29) |
| Study design | 12 / 12 | A systematic review of all the studies on the question |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 3 / 5 | 2022 — within 6 year(s) of the newest study here |
| Sample size | 1 / 4 | 20 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | A review of other studies — randomisation is not credited here |
| Times cited | 4 / 7 | Cited 89 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 14.8 citations a year over 6 year(s) since 2022 |
| Impact for its field and year | 2 / 6 | Cited 1.3× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 1 / 6 | Cited by 2 other studies in this library |
| Still being cited | 3 / 4 | Cited 68 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Margherita Ferrante: h-index 65 (OpenAlex, whole career) |
| Institution's track record | 0 / 3 | University of Catania: institution h-index 518 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 34979121) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 62 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
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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 names 8 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.
APA 7th
Cristaldi, A., Fiore, M., Oliveri Conti, G., Pulvirenti, E., Favara, C., Grasso, A., et al. (2022). Possible association between PM2.5 and neurodegenerative diseases: A systematic review. Environmental research. https://doi.org/10.1016/j.envres.2021.112581
Vancouver
Cristaldi A, Fiore M, Oliveri Conti G, Pulvirenti E, Favara C, Grasso A, et al. Possible association between PM2.5 and neurodegenerative diseases: A systematic review. Environmental research. 2022. doi:10.1016/j.envres.2021.112581. PMID: 34979121.
BibTeX
@article{cristaldi2022-34979121,
author = {Cristaldi, A. and Fiore, M. and Oliveri Conti, G. and Pulvirenti, E. and Favara, C. and Grasso, A. and Copat, C. and Ferrante, M.},
title = {{Possible association between PM2.5 and neurodegenerative diseases: A systematic review}},
journal = {Environmental research},
year = {2022},
doi = {10.1016/j.envres.2021.112581},
pmid = {34979121},
url = {https://doi.org/10.1016/j.envres.2021.112581}
}
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