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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

Post-ischemia–reperfusion cardiac end points in mice treated with 100 μg PM compared with saline control mice 18 hr postexposure (n = 5 mice/PM treatment group; n = 10 mice/saline group). (A) Recovery of LVDP. (B) Infarction. Abbreviations: C, coarse; F, fine; U, ultrafine. Error bars indicate SE.*p < 0.05 compared with saline.
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f6-ehp-117-1682: Post-ischemia–reperfusion cardiac end points in mice treated with 100 μg PM compared with saline control mice 18 hr postexposure (n = 5 mice/PM treatment group; n = 10 mice/saline group). (A) Recovery of LVDP. (B) Infarction. Abbreviations: C, coarse; F, fine; U, ultrafine. Error bars indicate SE.*p < 0.05 compared with saline.

Mentions: After ischemia reperfusion, the FR ultra-fine group showed significantly lower recovery of postischemic LVDP (Figure 6A) and increased infarct size (Figure 6B) compared with the saline controls. For representative photomicrographs, see Supplemental Material, Figure S1 (doi:10.1289/ehp.0900730.S1). The NR ultrafine group also showed similar responses at a nonsignificant level. The coarse PM groups showed the smallest changes followed by fine PM groups, indicating these effects were dependent on particle size fraction. Overall, the results showed that ultrafine PM exposure increased ischemia–reperfusion injury in the mouse heart.


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)

Post-ischemia–reperfusion cardiac end points in mice treated with 100 μg PM compared with saline control mice 18 hr postexposure (n = 5 mice/PM treatment group; n = 10 mice/saline group). (A) Recovery of LVDP. (B) Infarction. Abbreviations: C, coarse; F, fine; U, ultrafine. Error bars indicate SE.*p < 0.05 compared with saline.
© Copyright Policy - public-domain
Related In: Results  -  Collection

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

f6-ehp-117-1682: Post-ischemia–reperfusion cardiac end points in mice treated with 100 μg PM compared with saline control mice 18 hr postexposure (n = 5 mice/PM treatment group; n = 10 mice/saline group). (A) Recovery of LVDP. (B) Infarction. Abbreviations: C, coarse; F, fine; U, ultrafine. Error bars indicate SE.*p < 0.05 compared with saline.
Mentions: After ischemia reperfusion, the FR ultra-fine group showed significantly lower recovery of postischemic LVDP (Figure 6A) and increased infarct size (Figure 6B) compared with the saline controls. For representative photomicrographs, see Supplemental Material, Figure S1 (doi:10.1289/ehp.0900730.S1). The NR ultrafine group also showed similar responses at a nonsignificant level. The coarse PM groups showed the smallest changes followed by fine PM groups, indicating these effects were dependent on particle size fraction. Overall, the results showed that ultrafine PM exposure increased ischemia–reperfusion injury in the mouse heart.

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