The study investigated whether markers of airway and systemic inflammation, as well as heart rate variability (HRV) in asthmatics, change in response to fluctuations in ambient particulate matter (PM) in the coarse [PM with aerodynamic diameter 2.5–10 µm (PM2.5–10) ] and fine (PM2.5) size range. Twelve adult asthmatics, living within a 30-mile radius of an atmospheric monitoring site in Chapel Hill, North Carolina, were followed over a 12-week period. Daily PM2.5–10 and PM2.5 concentrations were measured separately for each 24-hr period. For a 1-µg/m3 increase in coarse PM, SDNN24HR, and ASDNN5 decreased 3.36% (p = 0.02) , and 0.77%, (p = 0.05) respectively. With a 1-µg/m3 increase in coarse PM, circulating eosinophils increased 0.16% (p = 0.01) , triglycerides increased 4.8% (p = 0.02) , and very low-density lipoprotein increased 1.15% (p = 0.01) . No significant associations were found with fine PM, and none with lung function. These data suggest that small temporal increases in ambient coarse PM are sufficient to affect important cardiopulmonary and lipid parameters in adults with asthma. Coarse PM may have underappreciated health effects in susceptible populations.

URL: http://www.ehponline.org/members/2007/9499/9499.html