Occupational exposures and colorectal cancers: A quantitative overview of epidemiological evidence

Table 1 Articles included in the literature review and meta-analysis, by cancer site, International Standard Industrial Classification code and exposure features

Authors	Cancer site	ISIC	Exposure	Article type	Estimate
Cantor et al[94]	Colorectal	01 - Crop and animal production	Aerial pesticide applicators	Cohort	RR
Greenburg et al[95]			Pesticides applicators	Cohort	RR
Lee et al[83]			Farming	Cohort	RR
Lo et al[90]			Pesticides	Case-Control	OR
Lynch et al[96]			Pesticides applicators	Cohort	RR
Wiklund and Dich[97]			Agriculture	Cohort	SIR
Mikoczy and Rylander[98]		03 - Fishing and aquaculture	Fishermen	Cohort	SIR
Finkelstein[99]		08 - Other mining and quarrying	Dust	Meta-analysis	SMR
Kusiak[100]			Miners	Cohort	SMR
Gubéran et al[57]		10 - Manufacture of food products	Butchers	Cohort	SMR
Fritschi et al[58]			Meat Workers	Cohort	SMR
McLean et al[59]			Meat Workers	Cohort	SMR
Carstensen et al[77]		11 - Manufacture of beverages	Brevery workers	Cohort	RR
Thygesen et al[78]			Brevery workers	Cohort	SIR
Goldberg and Thériault G[101]		13 - Manufacture of textile	Synthetic textiles	Cohort	SMR
Mastrangelo et al[24]			Textile	Meta-analysis	RR
Vobecky et al[102]			Carpet production	Cohort	SMR
Guay and Siemiatycki[54]		15 - Manufacture of leather and related products	Fur industry	Cohort	SMR
Montanaro et al[55]			Tannery workers	Cohort	SMR
Sweeney et al[103]			Fur industry	Cohort	SMR
Roscoe et al[104]		16 - Manufacture of wood and of products of wood and cork	Automotive wood modelists	Cohort	SMR
Swanson et al[26]			Automobile industry	Cohort	SMR
Rodu et al[62]		19 - Manufacture of coke and refined petroleum products	Petroleum	Cohort	SMR
Acquavella et al[70]		20 - Manufacture of chemicals and chemical products	Alachlor (herbicide)	Cohort	SIR
Berger and Manz[64]			Coke gas	Cohort	SMR
Fraser et al[65]			Fertilisers manufacturing	Cohort	SMR
Leet et al[66]			Alachlor (herbicide)	Cohort	SMR
Schnorr et al[67]			Polyurethane foam	Cohort	SMR
Tomenson et al[68]			Methil-methacrylate	Cohort	RR
Walker et al[69]			Methil-methacrylate	Cohort	SMR
Acquavella et al[63]		22 - Manufacture of rubber and plastics products	Polypropylene manufacturing	Cohort	SIR
Cowles et al[71]			Plastic and resins	Cohort	SMR
Kaleja et al[72]			Polypropylene production	Cohort	SIR
Lagast et al[73]			Polypropylene production	Meta-analysis	RR
Lewis et al[74]			Polypropylene production	Cohort	SIR
Sathiakumar et al[75]			Rubber industry	Cohort	SMR
McMichael et al[76]			Rubber industry	Cohort	SMR
Albin et al[106]		23 - Manufacture of other non-metallic mineral products	Asbestos cement workers	Cohort	RR
Jakobsson et al107]			Cement workers	Cohort	SMR
Seidman et al[108]			Asbestos	Cohort	SMR
Smailyte et al[52]			Cement workers	Cohort	SMR
Wingren[109]			Glass Workers	Cohort	SIR
Zhang et al[110]			Ceramic factories	Cohort	SMR
Jackobsson et al[43]		24 - Manufacture of basic metals	Stainless steel workers	Cohort	SIR
Redmond et al[40]			Steel workers	Cohort	SMR
Xu et al[42]			Iron and steel workers	Cohort	SMR
Wang et al[44]		26 - Manufacture of computer, electronic and optical products	Optical industry	Case-Control	OR
Ritz et al[60]		28 - Manufacture of machinery and equipment n.e.c	Aerospace workers	Cohort	RR
Delzell et al[111]		29 - Manufacture of motor vehicles	Motor vehicle manufacturing	Cohort	SMR
Innos et al[56]		31 - Manufacture of furniture	Wood dust	Cohort	SIR
Puntoni et al[48]		33 - Repair and installation of machinery and equipment	Shipyard	Cohort	RR
Puntoni et al[47]			Shipyard	Cohort	SMR
Nasterlack et al[112]		37 - Sewerage	Wastewater treatment	Cohort	SIR
Reynolds and Austin[113]		72 - Scientific research and development	Physics laboratory workers	Cohort	SIR
Ahn et al[114]		84 - Public administration and defence	Emergency responders	Cohort	SIR
Demers et al[115]			Firefighters	Cohort	SIR
Strand et al[116]			Asbestos (Military - Navy)	Cohort	SIR
Yamane[117]			United States Air Force workers	Cohort	SIR
Czene et al[118]		96 - Other personal service activities	Hairdressers	Cohort	SIR
Brownson et al[61]	Colon	01 - Crop and animal production	Agriculture	Case-control	OR
Cantor et al[94]			Aerial pesticide applicators	Cohort	SMR
Fredriksson et al[119]			Farmers	Case-Control	OR
Freedman et al[120]			Farmer s	Case-Control	OR
Koutros et al[82]			Aromatic amine pesticide	Cohort	RR
Rusiecki et al[121]			Pesticides	Cohort	RR
Wiklund and Dich[97]			Agriculture	Cohort	SIR
Fredriksson et al[119]		02 - Forestry and logging	Gardeners	Case-Control	OR
Mikoczy and Rylander[98]		03 - Fishing and aquaculture	Fishermen	Cohort	SIR
Brownson et al[61]		05 - Mining of coal and lignite	Coal Mining	Case-Control	OR
Tomaskova et al[122]			Black coal miners	Cohort	SMR
Brownson et al[61]		07 - Mining of metal ores	Metal mining	Case-control	OR
Gómez et al[123]			Mercury miners	Cohort	SMR
Brownson et al[61]		08 - Other mining and quarrying	Metal mining	Case-control	OR
Fredriksson et al[119]			Miners	Case-Control	OR
Brownson et al[61]		10 - Manufacture of food products	Food industry	Case-control	OR
Johnson et al[124]			Food industry	Case-Control	OR
Carstensen et al[77]		11 - Manufacture of beverages	Brevery workers	Cohort	RR
Thygesen et al[78]			Brevery workers	Cohort	SIR
Fredriksson et al[119]		14 - Manufacture of wearing apparel	Dressmakers and needle workers	Case-Control	OR
Brownson et al[61]		15 - Manufacture of leather and related products	Leather production	Case-control	OR
Montanaro et al[55]			Tannery workers	Cohort	SMR
Fredriksson et al[119]		16 - Manufacture of wood and of products of wood and cork	Lumberers and sawmill workers	Case-Control	OR
Roscoe et al[104]			Automotive wood model	Cohort	SMR
Simpson et al[125]			Wood dust	Case-Control	OR
Swanson et al[26]			Automobile industry	Cohort	SMR
Fredriksson et al[119]		17 - Manufacture of paper and paper products	Paper and pulp workers	Case-Control	OR
Brownson et al[61]		18 - Printing and reproduction of recorded media	Printing	Case-control	OR
Brownson et al[61]		19 - Manufacture of coke and refined petroleum products	Petroleum	Case-control	OR
Brownson et al[61]		20 - Manufacture of chemicals and chemical products	Chemical workers	Case-control	OR
Collins et al[126]			Methil-methacrylate	Cohort	SMR
Fraser et al[65]			Fertilisers manufacturing	Cohort	SMR
Fredriksson et al[119]			Chemical workers	Case-Control	OR
Schnorr et al[67]			Polyurethane foam industry	Cohort	SMR
Walker et al[69]			Methil-methacrylate	Cohort	SMR
Harrington and Goldblatt[105]		21 - Manufacture of basic pharmaceutical products and pharmaceutical preparations	Pharmaceutical industry	Cohort	SMR
McMichael et al[76]		22 - Manufacture of rubber and plastics product	Rubber industry	Cohort	SMR
Straif et al[127]			Rubber industry	Cohort	SMR
Smailyte et al[52]		23 - Manufacture of other non-metallic mineral products	Cement workers	Cohort	SIR
Jakobsson et al[107]		24 - Manufacture of basic metals	Stainless steel workers	Cohort	SIR
Redmond et al[40]			Steel workers	Cohort	SMR
Tokudome and Kuratsune[41]			Metal refinery	Cohort	SMR
Brownson et al[61]		25 - Manufacture of fabricated metal products	Metal manufacturing	Case-control	OR
Fredriksson et al[119]			Metal workers	Case-Control	OR
Fredriksson et al[119]		31 - Manufacture of furniture	Cabinet makers	Case-Control	OR
Innos et al[56]			Wood dust	Cohort	SIR
Fredriksson et al[119]		33 - Repair and installation of machinery and equipment	Mechanics	Case-Control	OR
Puntoni et al[48]			Shipyard	Cohort	SMR
Puntoni et al[47]			Shipyard	Cohort	SMR
Fredriksson et al[119]		49 - Land transport and transport via pipelines	Rail and road workers	Case-Control	OR
Reynolds and Austin[113]		72 - Scientific research and development	Physics laboratory workers	Cohort	SIR
Fredriksson et al[119]		81 - Services to buildings and landscape activities	Cleaners	Case-Control	OR
Baris et al[128]		84 - Public administration and defence	Firefighters	Cohort	SMR
Brownson et al[61]			National security	Case-control	OR
Youakim[129]			Firefighters	Cohort	RR
Fredriksson et al[119]		86 - Human health activities	Nurses	Case-Control	OR
Fredriksson et al[119]		96 - Other personal service activities	Dry Cleaners and hairdresser	Case-Control	OR
Cantor et al[94]	Rectum	01 - Crop and animal production	Aerial pesticide applicators	Cohort	RR
Settimi et al[130]			Agriculture	Case-Control	OR
Wiklund and Dich[97]			Agriculture	Cohort	SIR
Mikoczy and Rylander[98]		03 - Fishing and aquaculture	Fishermen	Cohort	SIR
Carstensen et al[77]		11 - Manufacture of beverages	Brevery workers	Cohort	RR
Thygesen et al[78]			Brevery workers	Cohort	SIR
Montanaro et al[55]		15 - Manufacture of leather and related products	Tannery workers	Cohort	SMR
Roscoe et al[104]		16 - Manufacture of wood and of products of wood and cork	Automotive wood model	Cohort	SMR
Rodu et al[62]		19 - Manufacture of coke and refined petroleum products	Petroleum industry	Cohort	SMR
Fraser et al[65]		20 - Manufacture of chemicals and chemical products	Fertilisers manufacturing	Cohort	SMR
Manuwald et al[131]			Dioxine compounds	Cohort	SMR
Schnorr et al[67]			Polyurethane foam industry	Cohort	SMR
Walker et al[69]			Methil-methacrylate	Cohort	SMR
McMichael et al[76]		22 - Manufacture of rubber and plastics product	Rubber industry	Cohort	SMR
Smailyte et al[52]		23 - Manufacture of other non-metallic mineral products	Cement workers	Cohort	SIR
Jakobsson et al[107]		24 - Manufacture of basic metals	Stainless steel workers	Cohort	SIR
Langård et al[132]			Ferrochromium/silicon	Cohort	SMR
Redmond et al[40]			Steel workers	Cohort	SMR
Malloy et al[133]		29 - Manufacture of motor vehicles	Metalworking fluids	Cohort	RR
Innos et al[56]		31 - Manufacture of furniture	Wood dust	Cohort	SIR
Puntoni et al[48]		33 - Repair and installation of machinery and equipment	Shipyard	Cohort	SMR
Puntoni et al[47]			Shipyard	Cohort	SMR
Reynolds and Austin[113]		72 - Scientific research and development	Physics laboratory workers	Cohort	SIR

SMR: Standardized mortality ratio; SIR: Standardized incidence ratio; ISIC: International Standard Industrial Classification.

Table 2 Pooled estimates for colorectal cancer, by industrial branch and study design

ISIC	Industrial branch	Cohort studies		Other study design2		All
		(95%CI)		(95%CI)		(95%CI)
		Crude RR	Adjusted RR3	Crude RR	Adjusted RR3	Crude RR	Adjusted RR3
1	Crop and animal production	0.86	-	2.6	-	0.86	-
		(0.81-0.91)		(1.12-6.02)		(0.76-0.97)
3	Fishing and aquaculture1	0.98	-	-	-	0.98	-
		(0.70-1.10)				(0.87-1.10)
8	Other mining and quarrying	0.8	-	0.84	-	0.83	-
		(0.70-0.92)		(0.77-0.92)		(0.77-0.89)
10	Manufacture of food products	1.21	-	-	-	1.21	-
		(0.76-1.92)				(0.76-1.92)
11	Manufacture of beverages	1.29	-	-	-	1.29	-
		(1.19-1.40)				(1.19-1.40)
13	Manufacture of textile	2.82	0.73	1.34	-	2	-
		(0.19-41.78)	(0.07-7.96)	(1.12-1.61)		(0.83-4.86)
15	Manufacture of leather and related products	1.7	-	-	-	1.7	-
		(1.24-2.34)				(1.24-2.34)
16	Manufacture of wood and of products of wood and cork	1.65	-	-	-	1.65	-
		(0.60-4.58)				(0.60-4.58)
19	Manufacture of coke and refined petroleum products1	1.21	-	-	-	1.21	-
		(0.69-2.12)				(0.69-2.12)
20	Manufacture of chemicals and chemical products	1.27	-	-	-	1.27	-
		(0.92-1.76)				(0.92-1.76)
22	Manufacture of rubber and plastics products	1.3	-	1.37	-	1.3	-
		(0.94-1.79)		(0.86-2.18)		(0.98-1.71)
23	Manufacture of other non-metallic mineral products	1.25	-	-	-	1.25	-
		(0.85-1.85)				(0.85-1.85)
24	Manufacture of basic metals	1.32	-	-	-	1.32	-
		(1.07-1.65)				(1.07-1.65)
26	Manufacture of computer, electronic and optical products1	-	-	2.14	-	2.14	-
				(1.02-4.50)		(1.02-4.50)
28	Manufacture of machinery and equipment nec1	2.2	-	-	-	2.2	-
		(1.03-4.72)				(1.03-4.72)
29	Manufacture of motor vehicles1	1.27	-	-	-	1.27	-
		(0.89-1.82)				(0.89-1.82)
31	Manufacture of furniture1	1.5	-	-	-	1.5	-
		(1.21-1.87)				(1.21-1.87)
33	Repair and installation of machinery and equipment	1.4	-	-	-	1.4	-
		(1.07-1.84)				(1.07-1.84)
37	Sewerage1	1.14	-	-	-	1.14	-
		(0.47-2.77)				(0.47-2.77)
72	Scientific research and development1	1.18	-	-	-	1.18	-
		(0.77-1.82)				(0.77-1.82)
84	Public administration and defence	0.97	0.87	-	-	0.97	0.87
		(0.62-1.52)	(0.58-1.30)			(0.62-1.52)	(0.58-1.30)
96	Other personal service activities1	1.09	-	-	-	1.09	-
		(0.98-1.21)				(0.98-1.21)
-	All industrial branches combined	1.18	1.18	1.36	1.13	1.19	1.12
		(1.08-1.30)	(1.08-1.30)	(0.94-1.97)	(0.81-1.57)	(1.09-1.33)	(1.03-1.23)
	Heterogeneity (I2)	84.1%		87.9%		84.3%

¹Only one study;

²Case-control studies and meta-analyses;

³Duval and Tweedie trim and fill method. RR: Relative risk; ISIC: International Standard Industrial Classification.

Table 3 Pooled estimates for colon cancer, by industrial branch and study design

ISIC	Industrial branch	Cohort studies		Other study design2		All
		(95%CI)		(95%CI)		(95%CI)
		Crude RR	Adjusted RR3	Crude RR	Adjusted RR3	Crude RR	Adjusted RR3
1	Crop and animal production	1	-	0.98	-	0.96	-
		(0.66-1.52)		(0.85-1.13)		(0.84-1.10)
2	Forestry and logging1	-	-	1.48	-	1.48	-
				(0.28-7.92)		(0.28-7.92)
3	Fishing and aquaculture1	0.93	-	-	-	0.93	-
		(0.79-1.09)				(0.79-1.09)
5	Mining of coal and lignite	0.9	-	1.1	-	0.92	0.9
		(0.68-1.20)		(0.42-2.91)		(0.69-1.21)	(0.69-1.17)
7	Mining of metals	0.19	-	1.5	-	0.57	-
		(0.05-0.71)		(0.65-3.64)		(0.08-4.30)
8	Other mining and quarrying1	-	-	0.91	-	0.91	-
				(0.45-1.83)		(0.45-1.83)
10	Manufacture of food products	1.06	-	1.32	-	1.28	-
		(0.44-2.57)		(0.93-1.87)		(0.98-1.70)
11	Manufacture of beverages	1.25	-	-	-	1.25	-
		(1.12-1.40)				(1.12-1.40)
14	Manufacture of wearing apparel1	-	-	0.66	-	0.66	-
				(0.20-2.20)		(0.20-2.20)
15	Manufacture of leather and related products	1.66	-	1.3	-	1.49	1.49
		(0.85-3.24)		(0.61-2.76)		(0.90-2.46)	(0.90-2.46)
16	Manufacture of wood and of products of wood and cork	2.19	1.2	0.53	-	0.96	0.96
		(0.56-8.52)	(0.35-4.16)	(0.37-0.78)		(0.46-1.97)	(0.46-1.97)
17	Manufacture of paper and paper products1	-	-	0.66	-	0.66	-
				(0.17-2.61)		(0.17-2.61)
18	Printing and reproduction of recorded media1	-	-	1.8	-	1.8	-
				(1.20-2.70)		(1.20-2.70)
19	Manufacture of coke and refined petroleum products1	-	-	1.3	-	1.3	-
				(0.51-3.29)		(0.51-3.29)
20	Manufacture of chemicals and chemical products	1.2	-	1.07	-	1.18	-
		(0.99-1.45)		(0.68-1.71)		(0.99-1.40)
21	Manufacture of basic pharmaceutical products and pharmaceutical preparations1	1.22	-	-	-	1.22	-
		(0.58-2.24)				(0.58-2.24)
22	Manufacture of rubber and plastics products	1.31	-	1.16	-	1.19	1.16
		(0.88-1.95)		(0.95-1.41)		(1.00-1.42)	(0.99-1.36)
23	Manufacture of other non-metallic mineral products1	0.77	-	-	-	0.77	-
		(0.29-2.06)				(0.29-2.06)
24	Manufacture of basic metals	1.75	1.61	-	-	1.75	1.61
		(1.16-2.65)	(1.09-2.38)			(1.16-2.65)	(1.09-2.38)
25	Manufacture of fabricated metal products	-	-	0.83	-	0.83	-
				(0.55-1.24)		(0.55-1.24)
31	Manufacture of furniture	1.65	-	0.8	-	1.4	-
		(1.24-2.20)		(0.27-2.36)		(0.77-2.54)
33	Repair and installation of machinery and equipment	1.91	1.81	0.99	-	1.75	-
		(1.39-2.62)	(1.39-2.37)	(0.43-2.29)		(1.27-2.41)
49	Land transport1	-	-	2.39	-	2.39	-
				(0.83-6.92)		(0.83-6.92)
72	Scientific research and development1	1.23	-	-	-	1.23	-
		(0.72-2.11)				(0.72-2.11)
84	Public administration and defence	1.32	-	0.9	-	1.19	-
		(0.85-2.05)		(0.59-1.38)		(0.85-1.67)
86	Human health activities1	-	-	1	-	1	-
				(0.49-2.05)		(0.49-2.05)
96	Other personal service activities1	-	-	1.37	-	1.37	-
				(0.51-3.72)		(0.51-3.72)
-	All industrial branches combined	1.23	1.23	1.03	1.03	1.13	1.13
		(1.09-1.39)	(1.09-1.39)	(0.92-1.15)	(0.92-1.15)	(1.05-1.22)	(1.05-1.22)
	Heterogeneity (I2)	70.5%		42.3%		61.4%

¹Only one study;

²Case-control studies and meta-analyses;

³Duval and Tweedie trim and fill method. RR: Relative risk; ISIC: International Standard Industrial Classification.

Table 4 Pooled estimates for rectal cancer, by industrial branch and study design

ISIC	Industrial branch	Cohort studies		Other study design2		All
		(95%CI)		(95%CI)		(95%CI)
		Crude RR	Adjusted RR3	Crude RR	Adjusted RR3	Crude RR	Adjusted RR3
1	Crop and animal production	0.86	-	1.5	-	0.97	-
		(0.74-1.00)		(0.55-2.45)		(0.67-1.41)
3	Fishing and aquaculture1	1.05	-	-	-	1.05	-
		(0.86-1.25)				(0.87-1.26)
10	Manufacture of food products1	0.75	-	-	-	0.75	-
		(0.33-1.70)				(0.33-1.70)
11	Manufacture of beverages	1.45		-	-	1.45	-
		(1.13-1.85)				(1.13-1.85)
15	Manufacture of leather and related products	2.06	-	-	-	2.06	-
		(0.36-3.76)				(0.91-4.65)
16	Manufacture of wood and of products of wood and cork1	0.4	-		-	0.4	-
		(0.06-2.53)				(0.06-2.53)
19	Manufacture of coke and refined petroleum products1	2.49	-	-	-	2.49	-
		(1.02-6.07)				(1.02-6.07)
20	Manufacture of chemicals and chemical products	1.22	-	-	-	1.22	-
		(0.62-2.41)				(0.62-2.41)
22	Manufacture of rubber and plastics products	0.82	-	-	-	0.82	-
		(0.55-1.22)				(0.55-1.22)
23	Manufacture of other non-metallic mineral products1	1.25	-	-	-	1.25	-
		(0.61-2.55)				(0.61-2.55)
24	Manufacture of basic metals	1.25	-		-	1.25	-
		(0.77-2.04)				(0.77-2.04)
29	Manufacture of motor vehicles	1.7	-	-	-	1.7	-
		(0.53-5.43)				(0.53-5.43)
31	Manufacture of furniture	1.32	-	-	-	1.32	-
		(0.93-1.88)				(0.93-1.88)
33	Repair and installation of machinery and equipment	0.76	-	-	-	0.76	-
		(0.42-1.38)				(0.42-1.38)
72	Scientific research and development1	1.1	-	-	-	1.1	-
		(0.26-1.95)				(0.52-2.34)
-	All industrial branches combined	1.15	1.15	1.5	1.5	1.15	1.15
		(0.99-1.34)	(0.99-1.34)	(0.55-2.45)	(0.55-2.45)	(0.99-1.34)	(0.99-1.34)
	Heterogeneity (I2)	53.8%		-		53.8%

¹Only one study;

²Case-control studies and meta-analyses;

³Duval and Tweedie trim and fill method. RR: Relative risk; ISIC: International Standard Industrial Classification.

Table 5 Colorectal cancer risk in occupational exposures, by gender

Site	Gender	Crude RR	95%CI	Adjusted RR1	95%CI
Colorectal	M	1.21	1.09-1.35	1.10	1.00-1.22
	F	0.94	0.85-1.04	0.93	0.84-1.04
Colon	M	1.07	0.97-1.18	-	-
	F	0.95	0.76-1.20	-	-
Rectum	M	1.11	0.93-1.32	-	-
	F	1.53	0.47-4.93	-	-

¹Duval and Tweedie trim and fill method. M: Male; F: Female; RR: Relative risk.