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Comparative toxicity of size-fractionated airborne particulate matter collected at different distances from an urban highway.

Cho SH, Tong H, McGee JK, Baldauf RW, Krantz QT, Gilmour MI - Environ. Health Perspect. (2009)

Bottom Line: Both NR and FR coarse PM produced significant pulmonary inflammation irrespective of distance, whereas both NR and FR ultrafine PM induced cardiac ischemia-reperfusion injury.On a comparative mass basis, the coarse and ultrafine PM affected the lung and heart, respectively.The results suggest that PM of different size-specific chemistry might be associated with different toxicologic mechanisms in cardiac and pulmonary tissues.

View Article: PubMed Central - PubMed

Affiliation: National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.

ABSTRACT

Background: Epidemiologic studies have reported an association between proximity to highway traffic and increased cardiopulmonary illnesses.

Objectives: We investigated the effect of size-fractionated particulate matter (PM), obtained at different distances from a highway, on acute cardiopulmonary toxicity in mice.

Methods: We collected PM for 2 weeks in July-August 2006 using a three-stage (ultrafine, < 0.1 microm; fine, 0.1-2.5 microm; coarse, 2.5-10 microm) high-volume impactor at distances of 20 m [near road (NR)] and 275 m [far road (FR)] from an interstate highway in Raleigh, North Carolina. Samples were extracted in methanol, dried, diluted in saline, and then analyzed for chemical constituents. Female CD-1 mice received either 25 or 100 microg of each size fraction via oropharyngeal aspiration. At 4 and 18 hr postexposure, mice were assessed for pulmonary responsiveness to inhaled methacholine, biomarkers of lung injury and inflammation; ex vivo cardiac pathophysiology was assessed at 18 hr only.

Results: Overall chemical composition between NR and FR PM was similar, although NR samples comprised larger amounts of PM, endotoxin, and certain metals than did the FR samples. Each PM size fraction showed differences in ratios of major chemical classes. Both NR and FR coarse PM produced significant pulmonary inflammation irrespective of distance, whereas both NR and FR ultrafine PM induced cardiac ischemia-reperfusion injury.

Conclusions: On a comparative mass basis, the coarse and ultrafine PM affected the lung and heart, respectively. We observed no significant differences in the overall toxicity end points and chemical makeup between the NR and FR PM. The results suggest that PM of different size-specific chemistry might be associated with different toxicologic mechanisms in cardiac and pulmonary tissues.

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Related in: MedlinePlus

Proinflammatory cytokines of MIP-2, TNF-α, and IL-6 in BALF 4 hr postexposure to NR and FR PM (n = 7 mice/group). Abbreviations: C, coarse; F, fine; SAL, saline; U, ultrafine. Error bars indicate SE.*p < 0.05, and **p < 0.01 compared with saline.
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f3-ehp-117-1682: Proinflammatory cytokines of MIP-2, TNF-α, and IL-6 in BALF 4 hr postexposure to NR and FR PM (n = 7 mice/group). Abbreviations: C, coarse; F, fine; SAL, saline; U, ultrafine. Error bars indicate SE.*p < 0.05, and **p < 0.01 compared with saline.

Mentions: Overall, the production of cytokines increased in a dose-dependent manner. The analysis of inflammatory cytokines by two-way ANOVA showed a particle size effect for MIP-2, TNF-α, and IL-6. At 4 hr (Figure 3), both the 100-μg and 25-μg doses of NR and FR coarse PM significantly increased the production of the MIP-2 and TNF-α. The responses to both NR and FR coarse PM were still significant with the 100-μg dose at 18 hr and to a lesser extent with the 25 μg (TNF-α only; data not shown). We found no significant differences for the other size fractions of any doses at any time points. At 4 hr (Figure 3), IL-6 was significantly increased with the high-dose coarse samples from both locations, and this effect persisted at 18 hr for the FR-sample (data not shown). LPS responses were much higher than PM at the 4 hr, indicating that the mice were capable of responding to an inflammatory agent.


Comparative toxicity of size-fractionated airborne particulate matter collected at different distances from an urban highway.

Cho SH, Tong H, McGee JK, Baldauf RW, Krantz QT, Gilmour MI - Environ. Health Perspect. (2009)

Proinflammatory cytokines of MIP-2, TNF-α, and IL-6 in BALF 4 hr postexposure to NR and FR PM (n = 7 mice/group). Abbreviations: C, coarse; F, fine; SAL, saline; U, ultrafine. Error bars indicate SE.*p < 0.05, and **p < 0.01 compared with saline.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2801189&req=5

f3-ehp-117-1682: Proinflammatory cytokines of MIP-2, TNF-α, and IL-6 in BALF 4 hr postexposure to NR and FR PM (n = 7 mice/group). Abbreviations: C, coarse; F, fine; SAL, saline; U, ultrafine. Error bars indicate SE.*p < 0.05, and **p < 0.01 compared with saline.
Mentions: Overall, the production of cytokines increased in a dose-dependent manner. The analysis of inflammatory cytokines by two-way ANOVA showed a particle size effect for MIP-2, TNF-α, and IL-6. At 4 hr (Figure 3), both the 100-μg and 25-μg doses of NR and FR coarse PM significantly increased the production of the MIP-2 and TNF-α. The responses to both NR and FR coarse PM were still significant with the 100-μg dose at 18 hr and to a lesser extent with the 25 μg (TNF-α only; data not shown). We found no significant differences for the other size fractions of any doses at any time points. At 4 hr (Figure 3), IL-6 was significantly increased with the high-dose coarse samples from both locations, and this effect persisted at 18 hr for the FR-sample (data not shown). LPS responses were much higher than PM at the 4 hr, indicating that the mice were capable of responding to an inflammatory agent.

Bottom Line: Both NR and FR coarse PM produced significant pulmonary inflammation irrespective of distance, whereas both NR and FR ultrafine PM induced cardiac ischemia-reperfusion injury.On a comparative mass basis, the coarse and ultrafine PM affected the lung and heart, respectively.The results suggest that PM of different size-specific chemistry might be associated with different toxicologic mechanisms in cardiac and pulmonary tissues.

View Article: PubMed Central - PubMed

Affiliation: National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.

ABSTRACT

Background: Epidemiologic studies have reported an association between proximity to highway traffic and increased cardiopulmonary illnesses.

Objectives: We investigated the effect of size-fractionated particulate matter (PM), obtained at different distances from a highway, on acute cardiopulmonary toxicity in mice.

Methods: We collected PM for 2 weeks in July-August 2006 using a three-stage (ultrafine, < 0.1 microm; fine, 0.1-2.5 microm; coarse, 2.5-10 microm) high-volume impactor at distances of 20 m [near road (NR)] and 275 m [far road (FR)] from an interstate highway in Raleigh, North Carolina. Samples were extracted in methanol, dried, diluted in saline, and then analyzed for chemical constituents. Female CD-1 mice received either 25 or 100 microg of each size fraction via oropharyngeal aspiration. At 4 and 18 hr postexposure, mice were assessed for pulmonary responsiveness to inhaled methacholine, biomarkers of lung injury and inflammation; ex vivo cardiac pathophysiology was assessed at 18 hr only.

Results: Overall chemical composition between NR and FR PM was similar, although NR samples comprised larger amounts of PM, endotoxin, and certain metals than did the FR samples. Each PM size fraction showed differences in ratios of major chemical classes. Both NR and FR coarse PM produced significant pulmonary inflammation irrespective of distance, whereas both NR and FR ultrafine PM induced cardiac ischemia-reperfusion injury.

Conclusions: On a comparative mass basis, the coarse and ultrafine PM affected the lung and heart, respectively. We observed no significant differences in the overall toxicity end points and chemical makeup between the NR and FR PM. The results suggest that PM of different size-specific chemistry might be associated with different toxicologic mechanisms in cardiac and pulmonary tissues.

Show MeSH
Related in: MedlinePlus