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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

Changes in respiratory responsiveness after MCh inhalation, measured by whole-body plethysmographs 18 hr after aspiration of 100 μg PM (n = 7 mice/group). (A) Penh. (B) MCh concentration producing a doubling of the Penh compared with saline vehicle. Abbreviations: Base, baseline; C, coarse; F, fine; SAL, saline; U, ultrafine. Error bars indicate SE.*p < 0.05 compared with saline aspiration treatment.
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f5-ehp-117-1682: Changes in respiratory responsiveness after MCh inhalation, measured by whole-body plethysmographs 18 hr after aspiration of 100 μg PM (n = 7 mice/group). (A) Penh. (B) MCh concentration producing a doubling of the Penh compared with saline vehicle. Abbreviations: Base, baseline; C, coarse; F, fine; SAL, saline; U, ultrafine. Error bars indicate SE.*p < 0.05 compared with saline aspiration treatment.

Mentions: The overall analysis of MCh responsiveness by three-way ANOVA indicated a significant effect by particle size and MCh dose. In the subsequent analyses, animals exposed to 100 μg of either NR or FR coarse PM showed significantly enhanced pulmonary responsiveness to the 12.5 mg/mL MCh dose at 18 hr postexposure compared with the saline group (Figure 5A). The 25-mg/mL MCh dose also enhanced pulmonary responsiveness but not to a significant level. When the data were transformed to reflect the EC200 (Figure 5B), we detected no statistical significance for the location and size factors. Nevertheless, mice exposed to 100 μg coarse PM required a non-significant but notably lower dose of MCh to achieve a 100% increase in Penh compared with the saline group.


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)

Changes in respiratory responsiveness after MCh inhalation, measured by whole-body plethysmographs 18 hr after aspiration of 100 μg PM (n = 7 mice/group). (A) Penh. (B) MCh concentration producing a doubling of the Penh compared with saline vehicle. Abbreviations: Base, baseline; C, coarse; F, fine; SAL, saline; U, ultrafine. Error bars indicate SE.*p < 0.05 compared with saline aspiration treatment.
© Copyright Policy - public-domain
Related In: Results  -  Collection

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

f5-ehp-117-1682: Changes in respiratory responsiveness after MCh inhalation, measured by whole-body plethysmographs 18 hr after aspiration of 100 μg PM (n = 7 mice/group). (A) Penh. (B) MCh concentration producing a doubling of the Penh compared with saline vehicle. Abbreviations: Base, baseline; C, coarse; F, fine; SAL, saline; U, ultrafine. Error bars indicate SE.*p < 0.05 compared with saline aspiration treatment.
Mentions: The overall analysis of MCh responsiveness by three-way ANOVA indicated a significant effect by particle size and MCh dose. In the subsequent analyses, animals exposed to 100 μg of either NR or FR coarse PM showed significantly enhanced pulmonary responsiveness to the 12.5 mg/mL MCh dose at 18 hr postexposure compared with the saline group (Figure 5A). The 25-mg/mL MCh dose also enhanced pulmonary responsiveness but not to a significant level. When the data were transformed to reflect the EC200 (Figure 5B), we detected no statistical significance for the location and size factors. Nevertheless, mice exposed to 100 μg coarse PM required a non-significant but notably lower dose of MCh to achieve a 100% increase in Penh compared with the saline group.

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