Table 3.
Tertile of exposure to Particulate Matter (PM10) in deep vein thrombosis cases and controls, by area of residence and year of examination*
| Tertile of Level of PM10(µg/m3)† | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cases | Controls | |||||||||||
| 12.0–44.2 | 44.2–48.1 | 48.1–51.5 | 12.0–44.2 | 44.2–48.1 | 48.1–51.5 | |||||||
| n | (%) | n | (%) | n | (%) | n | (%) | n | (%) | n | (%) | |
| Area of residence | ||||||||||||
| Milan, Urban Area | 72 | (18.9) | 156 | (40.9) | 153 | (40.2) | 70 | (13.3) | 265 | (50.5) | 190 | (36.2) |
| Milan, Suburban Area | 47 | (23.4) | 68 | (33.8) | 86 | (42.8) | 70 | (25.7) | 80 | (29.4) | 122 | (44.9) |
| Bergamo/Brescia | 3 | (37.5) | 1 | (12.5) | 4 | (50.0) | 10 | (55.6) | 3 | (16.7) | 5 | (27.8) |
| Po River Valley (towns>15,000 pop) | 16 | (34.0) | 12 | (25.5) | 19 | (40.4) | 33 | (45.8) | 12 | (16.7) | 27 | (37.5) |
| Po River Valley (other territory) | 42 | (35.3) | 28 | (23.5) | 49 | (41.2) | 62 | (40.8) | 35 | (23.0) | 55 | (36.2) |
| Varese, Como, Lecco | 24 | (92.3) | 1 | (3.9) | 1 | (3.9) | 20 | (83.3) | 1 | (4.2) | 3 | (12.5) |
| Lower Valtellina Valley | 14 | (100.0) | 0 | (0.0) | 0 | (0.0) | 29 | (100.0) | 0 | (0.0) | 0 | (0.0) |
| Alpine territory | 10 | (100.0) | 0 | (0.0) | 0 | (0.0) | 15 | (100.0) | 0 | (0.0) | 0 | (0.0) |
| Pre-Alpine territory | 56 | (86.2) | 9 | (13.9) | 0 | (0.0) | 94 | (91.3) | 9 | (8.7) | 0 | (0.0) |
| Year of study* | ||||||||||||
| 1995–1997 | 27 | (10.7) | 66 | (26.1) | 160 | (63.2) | 59 | (12.5) | 185 | (39.3) | 227 | (48.2) |
| 1998–2000 | 81 | (26.3) | 124 | (40.3) | 103 | (33.4) | 121 | (31.5) | 150 | (39.1) | 113 | (29.4) |
| 2001–2005 | 176 | (56.8) | 85 | (27.4) | 49 | (15.8) | 223 | (62.8) | 70 | (19.7) | 62 | (17.5) |
*
Year of DVT diagnosis for cases or date of examination for controls
†
Tertile of level of Particulate Matter<10 µm in aerodynamic diameter in control subjects during the year before the examination