Plasma nitrite is an indicator of acute changes in ambient air pollutant concentrations.
CONTEXT
Endothelial dysfunction has been suggested as a potential mechanism by which ambient air pollution may cause acute cardiovascular events. Recently, plasma nitrite has been developed as a marker of endothelial dysfunction.


OBJECTIVES
We examined the changes in plasma nitrite concentration associated with increases in ambient air pollutant concentrations in the previous 7 d.


MATERIALS AND METHODS
We linked up to three measurements of plasma nitrite concentrations obtained from 49 students to 24-h average concentrations of five criteria air pollutants [particle mass < 2.5 µm in aerodynamic diameter (PM(2.5)), carbon monoxide (CO), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and ozone (O₃)] measured at two monitoring sites closest to Rutgers University campus (6-15 miles) in New Jersey during the years 2006-2009. We examined the change in plasma nitrite associated with each interquartile-range (IQR) increase in pollutant concentration in the previous 24 h and six preceding 24- h periods, using linear mixed models.


RESULTS
IQR increases in mean PM(2.5) (7.0 µg/m³) and CO (161.7 parts per billion) concentrations in the first 24 h before the plasma nitrite measurement were associated with increased plasma nitrite concentrations (PM(2.5): 15.5 nanomolar; 95% confidence interval (CI): 2.4, 28.5; CO: 15.6 nanomolar; 95% CI: 2.4, 28.9). Increased plasma nitrite associated with IQR increases in O₃ and SO₂ concentrations over longer lags were observed.


DISCUSSION AND CONCLUSION
Rapid increases in plasma nitrite following exposure to ambient air pollutants support the hypothesis that ambient air pollution is associated with inducible nitric oxide synthase-mediated systemic inflammation in humans.
['Gandhi|Sampada K|SK|', 'Rich|David Q|DQ|', 'Ohman-Strickland|Pamela A|PA|', 'Kipen|Howard M|HM|', 'Gow|Andrew|A|']
D000293:Adolescent D000328:Adult D000397:Air Pollution D015415:Biomarkers D002248:Carbon Monoxide D018592:Cross-Over Studies D004311:Double-Blind Method D004730:Endothelium, Vascular D004784:Environmental Monitoring D005260:Female D006801:Humans D019570:Inhalation Exposure D008297:Male D008954:Models, Biological D009515:New Jersey D009573:Nitrites D010126:Ozone D052638:Particulate Matter D013458:Sulfur Dioxide D056647:Systemic Vasculitis D066007:Toxicokinetics D014504:Urban Health D055815:Young Adult
ambient air pollutants Air pollution plasma nitrite concentration