Long-term retention of particles in the human respiratory tract

Bailey, Michael R.; Fry, F. A.; James, Anthony

doi:10.1016/0021-8502(85)90037-0

Cited by 73 publications

(40 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Because particle transport from the alveolar region is slow, particularly in man (11), translocation of material from particles retained in the structures ofthe gas exchange region is recognized to be a very important clearance mechanism for the lung parenchyma. Moreover, recent studies have indicated that aerosol particles that were believed to be insoluble gradually dissolve in the lungs (12)(13)(14). This discovery, taken with the fact that retained particles are phagocytized by macrophages, indicated intracellular particle dissolution.…”

Section: Introductionmentioning

confidence: 99%

Intracellular Particle Dissolution in Alveolar Macrophages

Kreyling¹

1992

Environmental Health Perspectives

View full text Add to dashboard Cite

Aerosol particles deposited in the lungs that are not reaolily soluble in the epithelial lining fluid will be phagocytized by alveolar macrophages (AM). Inside the phagolysomal vacuole, the constituents ofthe plam allow dissolution ofavaiety ofcompounds at a higher rate than dissolutionietracelular lung fluids. Cielator concentration and a pH value ofabout 5 were found to control intracellular partice dissolution (IPD). Hence, IPD is the initial step oftranslocation ofdissolved material to blood, which is an important lung clearance nism for particles retined long term. IPD rtes of uniform test particles determined in human, baboon, and canine AM cultures were imilar to initialtrnslocation rates determined in lung clearnce studies ofthe same species after inhalation ofthe same test particles. IPD rate in cultured AM proved to be a sensitive functional parameter ofAM, which was used to identify changes in the clearance mechanism oftrnslocation during different exposure conditions.

show abstract

Section: Introductionmentioning

confidence: 99%

Intracellular Particle Dissolution in Alveolar Macrophages

Kreyling¹

1992

Environmental Health Perspectives

View full text Add to dashboard Cite

show abstract

“…Overload of the alveolar macrophage pool by a sufficient volume (approximately 1 μL/g of lung tissue) of particle reduces clearance time, which is on the order of 500 days for particles reaching the acinar surfaces 25,274 . Reduced clearance and increased inflammation aggravates fibrotic processes, with the implication is that increased toxicity reduces the concentration for overload-like symptoms to occur 18,22 .…”

Section: Discussionmentioning

confidence: 99%

“…Despite limited cytotoxicity of the iron-ore samples, extensive work in analysing particulate burden in vivo over the past three decades 18,22,24,25,27,225,274 has shown that even inert particles can cause obstructive and fibrotic changes if the particle clearance limit of pulmonary alveolar macrophages is reached 280 , and can occur over time as the half-life of particles reaching the acinar surfaces of the lungs is long; some 500 days 25 . An important characteristic of particle uptake underscoring the need for particle shape characterisation by electron microscopy is that particle uptake is also morphology dependent, and high-aspect ratio particles such as asbestos, glass fibre and multi-walled carbon-nanotubes (MWCNT) have been repeatedly shown to induce frustrated phagocytosis 30,35,127,213 .…”

Section: Discussionmentioning

confidence: 99%

“…The mechanism of this sequestration is not fully understood but may be related to immobilized particle-laden macrophages in connective tissue, lymphoid foci and other areas 27 . Specifically, ~ 60 % of inhaled fused aluminosilicate particles < 4 µm in were found to be retained in the lungs of healthy volunteers after 7 days, with a second clearance phase then following a much longer half-life of ~ 500 days 25 .…”

Section: Physiology Of Pam-mediated Particle Clearance In the Lungsmentioning

confidence: 99%

“…Both PM toxicity and concentration were independently found to exacerbate PAM death, reducing clearance rate and therefore increasing PM retention in the interstitial spaces of the lung. Persistent pro-inflammatory and pro-fibrotic immunological signalling was theorised to then initiate the fibrosing aspects of lung tissue damage and remodelling 13,[23][24][25][26][27][28][29][30][31][32] . Under this paradigm, experiments were designed to show how otherwise inert PM could exhaust the PAM pool increasing insoluble alveolar PM load and halflife in acute exposures 30,33,34 , demonstrating the importance of volumetric load, in addition particle number alone.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

In-vitro toxicology of respirable iron-rich particles relevant to mining industry: a high throughput framework for interpreting environmental particulate matter toxicity

Prakash¹

View full text Add to dashboard Cite

This project investigated the cytotoxicity profiles and toxicological properties of inhalable iron-rich particles generated by mining activity. National Environment Protection Measure (NEPM) ambient air quality regulations specifically regulate sub-10 µm (PM10) and sub-2.5 µm (PM2.5) diameter particle fractions corresponding to thoracic and respirable lung penetration, respectively. However, atmospheric concentrations of fugitive iron-rich particulates in iron ore mining and processing associated settlements raised concerns that NEPM limits may inadequately address the specific toxicological profile of iron-rich PM10 and potentially adsorbed organics in these regions. To address this, comparative cytotoxicity experiments were carried out in-vitro using a variety of particulate standards, featuring other frequently studied metal-oxides, to help bridge in-vivo and epidemiological knowledge in the literature with in-vitro toxicological results. This also required the development of a novel framework to interpret physical and physiological characteristics of coarse, poorly soluble metal-oxide particles by conducting a critical systematic literature review.Analysis by the ChemCentre, WA was taken into account with relation to potentially absorbed organics and the influence of Polycyclic Aromatic Hydrocarbons (PAHs) investigated.The protocols developed by this project are applicable to high-throughput assessment of particulate matter generated by mining activity, having defined methodology to rapidly acquire sufficient quantities of PM10 for assays which can be multiplexed and the effects of particulate interference on assays minimised. This includes the integration of non-destructive sterilisation techniques, physical characterising by particle-sizing, particle solubility analysis and observation of particle morphology by electron microscopy and elemental analysis. Epithelial (A549), fibroblast (LL24) and monocyte differentiated macrophage (U937) cell lines were tested to build a picture of particulate effects on the major lung cell types in the lung parenchyma; the alveolar epithelium, connective tissue and immune system.The effect of lung fluid surfactants on cytotoxicity was determined, and advanced tissue culture methods were trialled to improve the differentiation between particles provided by the endpoints.ii The ore samples from the Mining Area C (MAC), Yandi and Newman Hub mines in the Pilbara region were found to have an effect comparable to the cytotoxicity of micron-size iron oxide standards and selected standards of titanium dioxide, silicon dioxide and carbon black, whereas copper oxide was found to have some ten-fold greater cytotoxicity across the cell lines. However cytotoxicity as a principle differentiator of toxicity was found to be insufficient in differentiating the physiological response to iron-rich PM10 and insoluble metal-oxide standards. At high concentrations the dose-response relationship plateaued at a maximum value for iron-oxide standards and iron ore samples in the A549 and LL2...

show abstract

Allgemeiner Staubgrenzwert [MAK Value Documentation in German language, 1997]

2012

The MAK‐Collection for Occupational Health and Safety

View full text Add to dashboard Cite

Veröffentlicht in der Reihe Gesundheitsschädliche Arbeitsstoffe , 25. Lieferung, Ausgabe 1997 Der Artikel enthält folgende Kapitel: Allgemeiner Wirkungscharakter Exposition Toxikokinetik und Wirkung Partikeldeposition Retinierte Masse Partikelclearance bei Versuchstieren Partikelclearance beim Menschen Pathophysiologie der chronischen unspezifischen Staubwirkung beim Menschen Erfahrungen am Menschen DFG‐Studie „Chronische Bronchitis“ Längsschnittstudie an Gießereiarbeitern Querschnittstudie in der Landwirtschaft (Feldbau) Ergebnisse arbeitsmedizinischer Vorsorgeuntersuchungen Weitere Ergebnisse Tierexperimentelle Studien Chronische inhalative Studien Extrapolation von Tierversuchen auf den Menschen Abschätzung des Grenzwertes für die alveolengängige Staubfraktion Bewertung Einatembare Fraktion (Gesamtstaub) Alveolengängige Fraktion (Feinstaub) Geltungsbereich

show abstract

Long-term retention of particles in the human respiratory tract

Cited by 73 publications

References 9 publications

Intracellular Particle Dissolution in Alveolar Macrophages

Intracellular Particle Dissolution in Alveolar Macrophages

In-vitro toxicology of respirable iron-rich particles relevant to mining industry: a high throughput framework for interpreting environmental particulate matter toxicity

Allgemeiner Staubgrenzwert [MAK Value Documentation in German language, 1997]

Contact Info

Product

Resources

About