Refine
Document Type
- Conference Proceeding (4)
- Article (1)
Is part of the Bibliography
- yes (5)
Keywords
- Luftreinhaltung (4)
- Luftverschmutzung (3)
- Abgasemission (2)
- Düsseldorf (2)
- Gesundheitsförderung (2)
- Nachhaltigkeit (2)
- Radfahrerverkehr (2)
- Radweg (2)
- Stadtentwicklung (2)
- Stadtplanung (2)
Department/institution
BACKGROUND AND AIM [|] Due to their small size, ultrafine particles (UFP≤100nm) can reach deeply into the lungs and could exert higher toxicity on the body organs in comparison with fine particulate matter. Only ten epidemiological studies examined long-term UFP exposure and health effects according to the most recent review from 2019 that included studies until 2017. We systematically reviewed the literature on health effects of long-term exposure to UFP. METHOD [|] Epidemiological studies were searched comprehensively in PubMed and LUDOK (the Swiss literature database on air pollution and health) from January 2017 to September 2023. Original epidemiologic studies were included if they reported on the general or sub-populations, assessed long-term exposure of UFP measures, investigated clinical or preclinical health outcomes and reported a quantifiable measure of association. Internal validity of studies was evaluated with a risk of bias instrument. The project is funded by the Federal Ministry for the Environment, Nature Conversation, Nuclear Safety and Consumer Protection and supervised by the German Environment Agency (FKZ 3721 61 202 0). RESULTS [|] We identified 53 original studies investigating long-term associations. The vast majority were cohort studies (79.2%) conducted in the general population (62.3%). Half (54.7%) were located in western Europe. UFP was measured and modelled in various ways; more than a third of the studies (41.5%) used land-use regression models. Thirty studies adjusted for at least one co-pollutant. Most identified outcomes were cardiometabolic (43.4%), respiratory (13.2%) and birth outcomes (13.2%). Positive associations with long-term UFP exposure were reported for cardiometabolic, respiratory and birth outcomes for 78.5%, 42.9% and 50.0% of studies, respectively. CONCLUSIONS [|] The evidence base has increased substantially since the publication of the 2019 review. Positive associations were reported, in particular for cardiometabolic outcomes.
Background
Ultrafine particles (≤100 nm diameter) may have a higher toxicity than larger particles but are still not regulated nor part of routine air pollution monitoring. So far, health effects of long-term exposure to ambient ultrafine particles are not well understood, owing to a lack of exposure data and epidemiological studies.
Methods
We conducted a systematic review and meta-analysis on the health effects of long-term exposure to ultrafine particles, including studies published until December 2024. A meta-analysis was conducted for outcomes with at least four available effect estimates. Confidence in the body of evidence was evaluated using the Office of Health Assessment and Translation method.
Results
We identified 85 studies investigating various mortality, morbidity and subclinical outcomes. In meta-analyses of single-pollutant models, we found positive associations with natural mortality (hazard ratio 1.06, 95% CI 1.04–1.08) and C-reactive protein (10.14% increase (95% CI −0.51–21.99%) per 10 000 pt·cm−3 increase in long-term exposure to ultrafine particles, with low and inadequate levels of evidence, respectively. The remaining studies revealed overall limited evidence for adverse effects on a wide range of outcomes. Less than half of the studies adjusted for co-pollutants.
Conclusion
The evidence base on long-term health effects of ultrafine particles has increased substantially in the past decade, while the overall evidence for independent effects of long-term ultrafine particle exposure remains inadequate to low. More studies are needed to draw firm conclusions about the independent adverse effects of long-term ultrafine particles on various health end-points, with a special focus on the influence of co-pollutant adjustment.