Table 2.
Studies Included in the Overall Analysis of Traffic Density, Traffic-Related Air Pollution Models, or Gas Station Residential Proximity and Childhood Leukemia, 1999–2014
| First Author, Year (Reference No.) | RR | 95% CI | Type of Leukemia | No. of Exposed Cases | Study Location | Years | Child Age, Years | Exposure |
|
|---|---|---|---|---|---|---|---|---|---|
| Period | Exposure Assessed or Model Used | ||||||||
| Studies of Traffic Density or Traffic-Related Air Pollution Models | |||||||||
| Amigou et al., 2011 (52) | 3.1 | 0.8, 11.6 | AML | 3 | France | 2003–2004 | 0–14 | At diagnosis | Composite (density, proximity, and nitrogen dioxide) |
| Badaloni et al., 2013 (53) | 1.30 | 0.79, 2.12 | Leukemia | 74 | Italy | 1998–2001 | 0–10 | Lifetime (never moved) | Land-use regression models (nitrogen dioxide) |
| Crosignani et al., 2004 (54) | 4.31 | 1.47, 12.62 | Leukemia | 7 | Italy | 1978–1997 | 0–14 | At diagnosis | California LINE Source Dispersion Model, version 4 |
| Harrison et al., 1999 (55) | 1.16 | 0.74, 1.72 | Leukemia | 24 | United Kingdom | 1990–1994 | 0–15 | At diagnosis | Traffic density |
| Heck et al., 2014 (60) | 1.94 | 0.89, 4.19 | AML | 66 | United States | 1990–2007 | 0–5 | Birth | Air monitoring data for benzene (per IQR) |
| Langholz et al., 2002 (61) | 1.4 | 0.7, 3.0 | Leukemia | 46 | United States | 1978–1984 | 0–10 | Residence of longest duration | Traffic density |
| Pearson et al., 2000 (62) | 8.28 | 2.09, 32.8 | Leukemia | 8 | United States | 1976–1983 | 0–14 | At diagnosis | Traffic density (distance-weighted) |
| Raaschou-Nielsen et al., 2001 (56) | 0.4 | 0.1, 1.6 | Leukemia | 870a | Denmark | 1968–1991 | 0–14 | Childhood (all residences) | Operational Street Pollution Model (benzene) |
| Steffen et al., 2004 (12) | 1.1 | 0.8, 1.6 | Leukemia | 155 | France | 1995–1999 | 0–14 | Childhood (all residences) | Traffic density (heavy traffic roads) |
| Vinceti et al., 2012 (57) | 1.92 | 0.64, 5.78 | AML | 19 | Italy | 1998–2009 | 0–14 | At diagnosis | California LINE Source Dispersion Model, version 4 (per 1 µg/m3 benzene) |
| Visser et al., 2004 (58) | 4.9 | 1.6, 11.4 | ALL | 5 | Netherlands | 1989–1997 | 0–14 | At diagnosis | Traffic density (traffic intensity score) |
| Whitworth et al., 2008 (63) | 2.02 | 1.03, 3.96 | AML | 31 | United States | 1995–2004 | 0–19 | At diagnosis | Assessment System for Pollution Exposure Nationwide |
| Studies of Residential Proximity to Gas Stations | |||||||||
| Brosselin et al., 2009 (59) | 1.1 | 0.5, 2.5 | AML | 7 | France | 2003–2004 | 0–18 | Any | Residential proximity to garages or gas stations based on personal interviews; all residences from pregnancy to diagnosis |
| Harrison et al., 1999 (55) | 1.48 | 0.65, 2.93 | Leukemia | 8 | United Kingdom | 1990–1994 | 0–15 | At diagnosis | Living within 100 m of a gas station |
| Steffen et al., 2004 (12) | 7.7 | 1.7, 34.3 | AML | 4 | France | 1995–1999 | 0–14 | Childhood | Proximity to repair garages or gas stations, based on interviews about residential history from conception to diagnosis |
Abbreviations: ALL, acute lymphoblastic leukemia; AML, acute myeloid leukemia; CI, confidence interval; IQR, interquartile range; RR, relative risk.
a Total number of cases, including unexposed cases.