Lung function and indicators of exposure to indoor and outdoor particulate matter among asthma and COPD patients.
OBJECTIVE
Misclassification of exposure related to the use of central sites may be larger for ultrafine particles than for particulate matter < or =2.5 microm and < or =10 microm (PM(2.5) and PM(10)) and may result in underestimation of health effects. This paper describes the relative strength of the association between outdoor and indoor exposure to ultrafine particles, PM(2.5) and PM(10) and lung function.


METHODS
In four European cities (Helsinki, Athens, Amsterdam and Birmingham), lung function (forced vital capacity (FVC), forced expiratory volume in 1 second (FEV(1)) and peak expiratory flow (PEF)) was measured three times a day for 1 week in 135 patients with asthma or chronic obstructive pulmonary disease (COPD), covering study periods of >1 year. Daily concentrations of particle number, PM(2.5) and PM(10) were measured at a central site in each city and both inside and outside the subjects' homes.


RESULTS
Daily average particle number concentrations ranged between 2100 and 66 100 particles/cm(3). We found no association between 24 h average particle number or particle mass concentrations and FVC, FEV(1) and PEF. Substituting home outdoor or home indoor concentrations of particulate air pollution instead of the central site measurements did not change the observed associations. Analyses restricted to asthmatics also showed no associations.


CONCLUSIONS
No consistent associations between lung function and 24 h average particle number or particle mass concentrations were found in panels of patients with mild to moderate COPD or asthma. More detailed exposure assessment did not change the observed associations. The lack of association could be due to the high prevalence of medication use, limited ability to assess lagged effects over several days or absence of an effect.
de Hartog
J J
JJ
IRAS, Utrecht University, PO Box 80178, 3508 TD Utrecht, the Netherlands.
Ayres
J G
JG
Karakatsani
A
A
Analitis
A
A
Brink
H Ten
HT
Hameri
K
K
Harrison
R
R
Katsouyanni
K
K
Kotronarou
A
A
Kavouras
I
I
Meddings
C
C
Pekkanen
J
J
Hoek
G
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis; D001249:Asthma / Q000503:physiopathology*; D002947:Cities; D004739:England / Q000453:epidemiology; D005260:Female; D005387:Finland / Q000453:epidemiology; D005541:Forced Expiratory Volume / Q000502:physiology; D006115:Greece / Q000453:epidemiology; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D010366:Peak Expiratory Flow Rate / Q000502:physiology; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012129:Respiratory Function Tests; D014797:Vital Capacity / Q000502:physiology
D000393:Air Pollutants; D052638:Particulate Matter