Table 1.

General characteristics of the cohort studies included in the final analysis (n = 30).

References (Publication Year)	Type of Cohort Study	Country	Years Enrolled	Number of Cases	Cancer Site	Definition of Pollutant Exposure (Incremental Increase)	RR (95% CI)	Quality Assessment (Newcastle–Ottawa Stars)
Abbey et al. (1999) [15]	Prospective	USA	1977–1992	29 cases	Lung	PM10 24.08 µg/m3 increase	3.36 (1.57–7.19)	8
Hoek et al. (2002) [16]	Prospective	Netherlands	1986–1994	244 cases	Non-lung	NO2 30 µg/m3 increase	1.08 (0.63–1.85)	9
Nafstad et al. (2004) [17]	Prospective	Norway	1972–1998	382 cases	Lung	NOx 10 µg/m3 increase	1.11 (1.03–1.19)	8
Filleul et al. (2005) [18]	Prospective	France	1974–2000	178 cases	Lung	NO2 10 µg/m3 increase	1.48 (1.05–2.06)	9
Boldo et al. (2006) [19]	Prospective	Spain	1999–2003	1901 cases	Lung	PM2.5 15 µg/m3 increase	1.14 (1.04–1.23)	5
Brunekreef et al. (2009) [20]	Prospective	Netherlands	1987–1996	1935 cases	Lung	PM2.5 10 µg/m3 increase	1.06 (0.82–1.38)	8
McKean-Cowdin et al. (2009) [21]	Prospective	USA	1982–1988	1284 cases	Brain	PM2.5 10 µg/m3 increase	0.91 (0.74–1.11)	8
Cao et al. (2010) [22]	Prospective	China	1991–2000	624 cases	Lung	SO2 10 µg/m3 increase	1.04 (1.02–1.06)	8
Poppe CA et al. (2011) [23]	Prospective	USA	1983–1988	3194 cases	Lung	PM2.5 10 µg/m3 increase	1.14 (1.04–1.23)	8
Hart et al. (2011) [24]	Prospective	USA	1985–2000	800 cases	Lung	PM2.5 4 µg/m3 increase	1.02 (0.95–1.10)	6
Katanoda et al. (2011) [25]	Prospective	Japan	1983–1992	518 cases	Lung	PM2.5 10 µg/m3 increase	1.24(1.12–1.37)	8
Lipsett et al. (2011) [26]	Prospective	USA	1996–2005	234 cases	Lung	PM2.5 10 µg/m3 increase	0.95 (0.70–1.28)	8
Lepeule et al. (2012) [27]	Prospective	USA	1974–2009	350 cases	Lung	PM2.5 10 µg/m3 increase	1.37 (1.07–1.75)	9
Hales et al. (2013) [28]	Prospective	New Zealand	1996–1998	1686 cases	Lung	PM10 1 µg/m3 increase	1.02 (1.00–1.03)	8
Hu et al. (2013) [29]	Prospective	USA	1999–2009	255,128 women	Breast	PM10 10 µg/m3 increase	1.13 (1.02–1.25)	6
Carey et al. (2013) [30]	Prospective	United Kingdom	2003–2007	5273 cases	Lung	PM2.5 1.9 µg/m3 increase	1.04 (0.99–1.09)	6
Cesaroni et al. (2013) [31]	Prospective	Italy	2001–2010	12,208 cases	Lung	PM2.5 10 µg/m3 increase	1.05 (1.01–1.10)	8
Heinrich et al. (2013) [32]	Prospective	Germany	1990-2008	41 cases	Lung	PM10 7 µg/m3 increase	1.84 (1.23–2.74)	8
Yorifuji et al. (2013) [33]	Prospective	Japan	1999–2009	116 cases	Lung	NO2 10 µg/m3 increase	1.20(1.03–1.40)	8
Fischer et al. (2015) [34]	Prospective	Netherlands	2004–2011	53,735 cases	Lung	PM10 10 µg/m3 increase	1.26 (1.21–1.30)	8
Ancona et al. (2015) [35]	Retrospective	Italy	2001–2010	2196 cases	All	PM10 27 µg/m3 increase	1.04 (0.92–1.17)	8
Chen et al. (2016) [36]	Prospective	China	1998–2009	140 cases	Lung	PM10 10 µg/m3 increase	1.05 (1.03–1.06)	9
Eckel et al. (2016) [37]	Prospective	USA	1988–2009	352,053 cases	Lung	PM2.5 5.3 µg/m3 increase	1.15 (1.14–1.16)	7
Weichenthal et al. (2016) [38]	Prospective	Canada	1991–2009	3200 cases	Lung	PM2.5 10 µg/m3 increase	1.05 (1.00–1.10)	7
Wong et al. (2016) [39]	Prospective	Hong Kong	1998–2011	4531 cases	All	PM2.5 10 µg/m3 increase	1.22 (1.11–1.34)	8
Cohen et al. (2016) [40]	Prospective	Israel	1992–2013	105 cases	All	NOx 10 ppb increase	1.08 (0.93–1.26)	9
Guo et al. (2017) [41]	Prospective	China	1990–2009	315,530 cases	Lung	PM2.5 10 µg/m3 increase	1.08 (1.07–1.09)	5
Pun et al. (2017) [42]	Prospective	USA	2000–2008	255,544 cases	All	PM2.5 10 µg/m3 increase	1.11 (1.09–1.12)	7
Deng et al. (2017) [43]	Prospective	USA	2000–2009	20,221 cases	Liver	PM2.5 10 µg/m3 increase	1.18 (1.16–1.20)	8
Turner et al. (2017) [7]	Prospective	Canada	1982–2004	43,320 cases	Non-lung	NO2 6.5 ppb increase	1.06 (1.02–1.10)	8

Abbreviations: CI, confidence interval; NO, nitrogen oxides; PM, particulate matter; ppb, parts per billion; RR, relative risk.