98
Views
53
CrossRef citations to date
0
Altmetric
Original Articles

Metals Mimic Airway Epithelial Injury Induced by in Vitro Exposure to Utah Valley Ambient Particulate Matter Extracts

, , , , &
Pages 1087-1112 | Published online: 01 May 2012
 

Abstract

Epid emiologic studies have shown positive associations between changes in ambient particulate matter (PM) levels in Utah Valley during 1986–1988, and the respiratory health of the local population. Ambient PM reductions coincided with closure of an open-hearth steel mill, the major industrial source of particulate emissions in the valley. In this report, water extracts of PM filters from steel mill ope rational (UE-86, UE-88) and closure (UE-87) periods were analyzed for their elemental composition. Their relative toxicity was determined by expos ing primary rodent airway epithelial cultures to equal masses of extracted material. To elucidate extract subcomponents mediating the effects observed, cells were also exposed to surrogate metal mixtures. Potential interactions between the two predominant metals in the UE-86/88 samples, zinc (Zn) and copper (Cu), were further investigated. Data indicated that, relative to the UE-87 (plant closed) sample, UE-86/88 samples contained more sulfate, calcium, potassium, magnesium and, although presentin much lower amounts, a variety of metals including Zn, Cu. iron, lead, strontium, nickel, manganese, and vanadium N). Cell expos ure to UE-86 and UE-88, but not UE-87, resulted in time- and concentration-dependent epithelial injury based on biochemical and light/electron microscopic changes. Cell injury induced by metal mixtures containing equivalent amounts of Zn + Cu + V was commensurate with that induced by the corresponding extract, although divergent antioxidant responses were observed. Expos ure to Zn + Cu resulted in significantly greater epithelial toxicity and stress (c-Jun N-terminal protein kinase activation) responses than did exposure to Zn or Cu individually. The parallel epithelial injury induced by the extracts and their surrogate Zn+Cu+V mixtures suggests that these metals are mediating the acute airwayep ithelial effects observed; however, metal interactions appear to play a critical role in the overall cellular effects induced by the PM-derived extracts. These experimental findings are in good accord with epidemiologic reports of adverse airway and respiratory health effects in Utah Valley residents.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.