Concept
Particulate matter
Particulate-matter research measures PM2.5 or related particles and their links to health, chemistry or source — including wildfire smoke and long-term urban exposure.
PM2.5 is the undergraduate air-pollution metric that actually has a body of outcome studies.
Evidence
What the evidence shows
Drawn from 10 studies in this library. Each finding starts with a plain-language takeaway, then the denser detail. Supports means evidence for a finding; Challenges means evidence against a stated position; Qualifies marks scope with a short note on each study’s contribution. Challenged positions are labeled — they are not findings.
This library holds 10 empirical papers on particulate matter with measured outcomes rather than reviews.
- PM2.5 oxidative potential modifies heart-attack risk
- Prenatal PM2.5 linked to preterm birth in Puerto Rico
- PM2.5 lowers lung function in COPD, NO2 in asthma
Study Role Design N Population Outcome PM2.5 oxidative potential modifies heart-attack risk Supports Case-controlCase-crossover of MI ED visits vs daily PM2.5 weighted by city oxidative potential N=30101 · 30,101 myocardial infarction emergency visits in 16 Canadian cities MI emergency visits across 16 Canadian cities MI visit risk per PM2.5 and redox-weighted PM2.5 Prenatal PM2.5 linked to preterm birth in Puerto Rico Supports CohortPROTECT pregnancy cohort with pregnancy-average PM2.5 and preterm-birth risk ratios N=1092 · 1,092 PROTECT participants with live singleton births in 21 municipalities Pregnant women in the PROTECT cohort in Puerto Rico Preterm birth associated with prenatal PM2.5 (with phthalate-interaction tests) PM2.5 lowers lung function in COPD, NO2 in asthma Supports CohortRepeated home/clinic spirometry paired with ambient PM and gases in Rome N=29 · 29 adults with COPD, asthma, or IHD; 449 spirometries Adults with COPD, asthma, or ischemic heart disease in Rome Short-term lung-function changes related to PM2.5 metals and NO2 Same-day PM2.5 raises myocardial-infarction visits more where particles deplete glutathione, and NOx–ozone oxidant capacity adds further risk.
In the PROTECT birth cohort, an IQR rise in pregnancy-average PM2.5 was associated with higher preterm-birth risk among relatively healthy Puerto Rican women.
In a Rome panel, fine particles reduced FVC and FEV1 among COPD patients, NO2 reduced FEV1 among asthmatics, and IHD patients showed no spirometric response.
Beijing PM2.5 averaged 100.66 μg/m³ and tracked higher influenza-like illness mainly in flu season.
Open questions
Tensions and limits
Some items are genuine disagreements on the same question. Others mark different assays, populations, or outcomes — limits on how far one study travels — not a forced fight between papers.
A time-series in one city or a prenatal cohort is not a global mortality function.
- PM2.5 oxidative potential modifies heart-attack risk
- Prenatal PM2.5 linked to preterm birth in Puerto Rico
Study Role Design N Population Outcome PM2.5 oxidative potential modifies heart-attack risk Supports Case-controlCase-crossover of MI ED visits vs daily PM2.5 weighted by city oxidative potential N=30101 · 30,101 myocardial infarction emergency visits in 16 Canadian cities MI emergency visits across 16 Canadian cities MI visit risk per PM2.5 and redox-weighted PM2.5 Prenatal PM2.5 linked to preterm birth in Puerto Rico Supports CohortPROTECT pregnancy cohort with pregnancy-average PM2.5 and preterm-birth risk ratios N=1092 · 1,092 PROTECT participants with live singleton births in 21 municipalities Pregnant women in the PROTECT cohort in Puerto Rico Preterm birth associated with prenatal PM2.5 (with phthalate-interaction tests)
Common misconceptions
All PM2.5 is chemically the same.
Source, size fraction and co-pollutants change both measurement and outcome.
Exam-style questions
Short-answer questions that ask you to explain or compare, not recall.
What does particulate matter mean in this library?
Particulate-matter research measures PM2.5 or related particles and their links to health, chemistry or source — including wildfire smoke and long-term urban exposure.
Name one empirical finding from the particulate matter papers.
Same-day PM2.5 raises myocardial-infarction visits more where particles deplete glutathione, and NOx–ozone oxidant capacity adds further risk.
What is a limit of particulate matter evidence here?
A time-series in one city or a prenatal cohort is not a global mortality function.
The studies
10 studies in this library bear on Particulate matter, ordered by citations. The first 8 are shown.
- PM2.5 components and hospital admissions
A 10 μg/m³ rise in two-day PM2.5 was linked to about 1.9% more cardiac emergency admissions in 26 US communities.
- Short-term PM2.5 raises deaths and Parkinson’s admissions
Two-day average PM2.5 is linked to higher all-cause mortality and to hospital admissions for Parkinson’s disease and diabetes among US Medicare enrollees.
- Low PM2.5 still tracks Canadian mortality
In 299,500 Canadians, a 10 μg/m³ rise in PM2.5 was linked to HR 1.26 for non-accidental death even at mean 6.3 μg/m³.
- Traffic PM and nearby roads raised diabetes incidence
In the Heinz Nixdorf Recall cohort, living within 100 m of a busy road and higher total PM10 were associated with more new type 2 diabetes over ~5 years.
- Beijing PM2.5 and influenza-like illness
Beijing PM2.5 averaged 100.66 μg/m³ and tracked higher influenza-like illness mainly in flu season.
- 2012 Colorado wildfire PM raised asthma visits
During a 32-day 2012 fire period, modeled PM2.5 associated with asthma/wheeze and COPD ED visits; cardiovascular associations were largely null.
- PM2.5 lowers lung function in COPD, NO2 in asthma
In a Rome panel, fine particles reduced FVC and FEV1 among COPD patients, NO2 reduced FEV1 among asthmatics, and IHD patients showed no spirometric response.
- PM2.5 oxidative potential modifies heart-attack risk
Same-day PM2.5 raises myocardial-infarction visits more where particles deplete glutathione, and NOx–ozone oxidant capacity adds further risk.
Show 2 more studiesShow fewer studies
- Saharan dust days worsen coarse-PM mortality
In Rome 2001–2004, coarse PM raised death risk most on Saharan dust days; fine PM effects were not modified by dust.
- Prenatal PM2.5 linked to preterm birth in Puerto Rico
In the PROTECT birth cohort, an IQR rise in pregnancy-average PM2.5 was associated with higher preterm-birth risk among relatively healthy Puerto Rican women.
Learn alongside
Change log
What changed
Dated edits to this page's evidence: studies added or removed from a claim, claims added or withdrawn, and new explanations tagged here. Rewordings are not listed.
- Concept page published