Table 1 Demographic and TAA variables stratified by residential distance to I-93.
From: Effect of time-activity adjustment on exposure assessment for traffic-related ultrafine particles
Characteristic | Total (N=204) | ≤50 m (N=32) | 51–500 m (N=129) | >1,000 m (N=43) |
|---|---|---|---|---|
Demographic variables | ||||
Age, mean (SD) | 59.1 (12.4) | 52.7 (10)a,b | 60.5 (11.7)b | 59.6 (14.8) |
Female | 66% | 56%a | 66% | 72% |
White | 70% | 58%a | 66%c | 93% |
Smoking status | ||||
Current | 22% | 19%a | 27%c | 7% |
Former | 35% | 16%a,b | 36%b | 47% |
Never | 37% | 50%b | 31%b,c | 44% |
Missing | 6% | 16% | 6% | 2% |
Educational attainment | ||||
Less than high school diploma | 26% | 38%a | 26% | 16% |
High school diploma | 31% | 31%a | 38% | 12% |
Undergraduate school | 28% | 28% | 25% | 35% |
Graduate school | 15% | 3%a,b | 11% | 37% |
Annual Income | ||||
Less than $24,999 | 19% | 12% | 12% | 14% |
$25,000–$74,999 | 14% | 19%b | 44%b,c | 25% |
$75,000 or more | 35% | 28% | 33% | 42% |
Do not know/refused | 32% | 41%a,b | 11%c | 19% |
Employment | ||||
Working full time or part time | 45% | 66%a,b | 36%b,c | 58% |
Retired, disabled or unemployed | 52% | 28%a,b | 62%b,c | 40% |
Missing | 3% | 6%a,b | 2%b,c | 2% |
Time-activity adjustment variables | ||||
Workday/weekday (mean hours (SD)) | ||||
Inside home | 17.14 (4.8) | 15.07 (5.4)a | 17.94 (4.2)c | 16.34 (5.4) |
Outside home | 0.95 (2.53) | 0.48 (1.16) | 0.99 (2.14) | 1.13 (3.78) |
Work | 3.95 (4.8) | 7.66 (5.67)a,b | 2.68 (4.07)b,c | 4.96 (4.68) |
Other | 1.56 (2.53) | 0.52 (0.96)a | 2.02 (2.97)c | 1.02 (1.47) |
Highway | 0.40 (0.97) | 0.27 (0.48) | 0.37 (0.71) | 0.55 (1.58) |
Non-workday/weekend (mean hours (SD)) | ||||
Inside home | 18.56 (4.6) | 17.24 (4.6) | 19.45 (3.5)c | 17.09 (6.2) |
Outside home | 1.72 (3.5) | 2.88 (5.33) | 1.48 (2.72) | 1.63 (4.01) |
Work | 1.46 (3.71) | 1.86 (2.91) | 0.63 (1.98)c | 3.33 (6.12) |
Other | 1.89 (2.49) | 1.42 (2.24) | 2.13 (2.62) | 1.58 (2.25) |
Highway | 0.37 (0.62) | 0.6 (0.79) | 0.32 (0.56) | 0.37 (1.76) |
Air conditioner (AC) | ||||
Yes | 85% | 81% | 88% | 81% |
Open windows in winter | ||||
Yes | 54% | 53%a | 59%c | 40% |
Missing | <1% | 0% | <1% | 0% |
Open windows in summer | ||||
Yes | 88% | 88% | 87% | 93% |
Missing | 2% | 3% | 1% | 2% |
