Day-to-day particulate exposures and health changes in Los Angeles area residents with severe lung disease

We measured particulate matter (PM2.5 and PM10) exposures, home temperature , arterial blood oxygen saturation, blood pressure, and lung function in 30 volunteer Los Angeles area residents during four-day intervals. Continuous Holter electrocardiograms were recorded in a subgroup on the first two day s. Subjects recorded symptoms and time-activity patterns in diaries during monitoring, and during a reference period one week earlier/later. All subje cts had severe chronic obstructive pulmonary disease. PM10 (24-hr mean) at monitoring stations near subjects' homes averaged 33 mu g/m(3), and ranged from 9 to 84 mu g/m(3). Ln longitudinal analyses, day-to-day changes in PM2 .5 and PM10 outside subjects' homes significantly tracked concurrent statio n PM10 (r(2) = 0.22 and 0.44, respectively). Indoor and personal concentrat ions were less related to station readings (r(2) less than or equal to 0.1) , but tracked each other (r(2) greater than or equal to 0.4). In-home tempe ratures tracked outdoor temperatures more for lows (r(2) = 0.27) than for h ighs (r(2) = 0.10). These longitudinal relationships of subject-oriented an d station PM measurements were generally similar to cross-sectional relatio nships observed previously in similar subjects. Among health measurements, only blood pressure showed reasonably consistent unfavorable longitudinal a ssociations with particulates, more with station or outdoor PM than with in door or personal PM.