Evidence map›Paper›PMID 39788181›Full record

ArticleEnvironmental pollution (Barking, Essex : 1987)2025

Urban emissions of fine and ultrafine particulate matter in Los Angeles: Sources and variations in lung-deposited surface area.

Yousef Alramzi, Yashar Aghaei, Mohammad Mahdi Badami, Mohammad Aldekheel, Ramin Tohidi, Constantinos Sioutas

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Environmental pollution (Barking, Essex : 1987), 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Article
  2. Article
  3. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Yousef AlramziUniversity of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA.
Yashar AghaeiUniversity of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA.
Mohammad Mahdi BadamiUniversity of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA.
Mohammad AldekheelKuwait University, Department of Civil Engineering, P.O Box 5969, Safat, 13060, Kuwait.
Ramin TohidiUniversity of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA.
Constantinos SioutasUniversity of Southern California, Department of Civil and Environmental Engineering, Los Angeles, CA, USA. Electronic address: sioutas@usc.edu.

Funding

Interplay Between Macrophages, Lipid Oxidation and the Nrf2/HO-1 Axis in the Cardiometabolic Toxicity Induced by Ultrafine ParticlesR01ES032806 · NIEHS · UNIVERSITY OF CALIFORNIA LOS ANGELES · PI ARAUJO, JESUS ANTONIO · 2021 to 2025
$2.0M
Novel Approaches for Improving Inflammation Resolution Following Chronic Exposure to Air PollutantsR01ES033660 · NIEHS · UNIVERSITY OF CALIFORNIA LOS ANGELES · PI REDDY, SRINIVASA T. · 2022 to 2025
$1.8M
NIEHS NIH HHS R01 ES032806NIEHS NIH HHS R01 ES033660
6 · The paper itself

Abstract

Airborne particulate matter (PM) in urban environments poses significant health risks by penetrating the respiratory system, with concern over lung-deposited surface area (LDSA) as an indicator of particle exposure. This study aimed to investigate the diurnal trends and sources of LDSA, particle number concentration (PNC), elemental carbon (EC), and organic carbon (OC) concentrations in Los Angeles across different seasons to provide a comprehensive understanding of the contributions from primary and secondary sources of ultrafine particles (UFPs). Hourly measurements of PNC and LDSA were conducted using the DiSCmini and Scanning Mobility Particle Sizer (SMPS), while OC and EC concentrations were measured using the Sunset Lab EC/OC Monitor. The results showed distinct diurnal trends in PNC and EC, with peaks occurring in the early morning and evening, which were consistent with periods of increased traffic volume. During warmer periods, a midday increase in PNC was observed, attributed to photochemical reactions. In contrast, a nighttime peak during colder months suggested the formation of secondary aerosols through aqueous-phase chemistry. Additionally, the DiSCmini consistently reported higher LDSA values than SMPS, indicating the presence of irregularly shaped UFPs, particularly during periods of heavy traffic flow. Positive Matrix Factorization (PMF) analysis identified three primary sources. Factor 1 (photochemically influenced processes), driven by secondary organic aerosol formation during warmer periods, contributed to 19% of LDSA. Factor 2, in which primarily traffic influenced emissions were the dominant contributor, accounting for 70% of LDSA and associated with high loadings of OC (61%), EC (78%), and NO

Indexed as

Air PollutantsLungParticulate MatterAir PollutionCitiesEnvironmental MonitoringHumansLos AngelesParticle SizeSeasonsVehicle EmissionsAir PollutantsParticulate MatterVehicle EmissionsLung-deposited surface areaNighttime chemistryPhotochemistryPositive matrix factorization– ultrafine particlesVehicular emissions

Identifiers

PMID39788181
PMCPMC11813679

What OpenQuestion holds

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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.