Table 2.

Main results on lung cancer from the selected studies.

Author, year	Type of fiber	Exposurea Min.range; Max. range	Main effect resultsb (IC95%)	Other observations and results
Lash T et al., 1997	Chrysotile	<100 f-y/ml; >400 f-y/ml	SMR = 0.8 (0.21–2.01); SMR = 1.1 (0.55–2.11)	Measurement of the power of asbestos to cause lung cancer by the cumulative exposure coefficient of asbestos (K1). Given the fixed effects model: K1 = 0.42×10−3 (0.22–0.69×10−3) ml/f-y. Given the random effects model: K1 = 2.6×10−3 (0.65–7.4×10−3)ml/f-y. For mining cohorts: K1 = 0.25×10−3 (0.01–0.45×10−3) ml/f-y. For cement production cohorts: K1 = 3.4×10−3 (0.1–8.8×10−3) ml/f-y. For textile cohorts: K1 = 7.7×10−3 (4.7–12×10−3) ml/f-y.
		<1 mppcf-y; ≥1000 mppcf-y	SMR = 1.17 (0.71–1.83); SMR = 3.04 (1.9–4.6)
	Amphibole: crocidolite Amphibole: amosite	28.8 f-y/ml; Value not given value	SMR = 2.64 (2.15–3.24) SMR = 2.64 (1.44–4.42); SMR = 11.7 (5.83–20.94)
	Amphibole: tremolite	<1 month exposure; ≥2 years exposure	SMR = 2.06 (0.41–6.0); SMR = 7.91 (5.47–11.05)
			SMR = 2.04 (0.82–4.21); SMR = 5.58 (1.49–14.22)
		<6 f-y/ml; ≥250 f-y/ml
		<25 f-y/ml; >500 f-y/ml
	Mixed	<2,7 f-y/ml; >150f-y/ml	SMR = 1.4 (0.42–3.07); SMR = 2.69 (0.3–9.71)
		<6 mppcf-y; ≥750 mppcf-y	SMR = 1.04 (0.21–3.02); SMR = 7.78 (3.12–16.03)
Hodgson J et al., 2000	Chrysotile	22 f/ml-y; 600 f/ml-y	RL = 1.3 (−0.29–3.4); RL = 0.06 (0.042–0.079)	Measurement of lung cancer risk calculated as expected percentage of mortality per fiber/ml-year of exposure: RL = 100 (O-E) / E RL in exposed to chrysotile = 0.062 (p<0.001); to crocidolite RL = 4.2 (IC95% 2.8–5.8) p = 0.09; to amosite RL = 5.2 (IC95% 4.0–6.5) p = 0.022; and to mixed fibers RL = 0.47 (p<0.001). Long fibers represent an increased risk of carcinogenicity. Short exposure times at high exposure results in a higher risk than long exposure times at low concentration.
	Amphibole: crocidolite	16.4 f/ml-y; 120 f/ml-y	RL = 5.2 (0.71–12.0); RL = 10.0 (3.9–21.0)
	Amphibole: amosite	23.6 f/ml-y; 65 f/ml-y	RL = 1.9 (−0.44–5.1); RL = 5.8 (4.4–0.74)
	Mixed	13 f/ml-y; 750 f/ml-y	RL = 6.2 (−0.77–21.0); RL = 0.21 (0.14–0.3)
Berry G et al., 2007	Chrysotile	25 f/ml-y	RR = 2.05; RR = 1.025; RR = 1.06c	Higher risk of amphibole exposure was observed. There is no significant increase in lung cancer. Taconite miners: No clear increase in lung cancer mortality 10 years after first exposure.
			RL = 0.062
	Amphibole: crocidolite	General	RL = 4.2
	Amphibole: amosite		RL = 5.25%
	Mixed	General	RL = 0.47
Berman W et al., 2008	Chrysotile	Length >10 μm and Thickness <0.2;< 0.4; >0.2 μm	KL = 0.38 (0,0–1.3); KL = 0,49 (0.092–1.4); KL = 0,52 (0.13–1.3)	Fibers >10 μm long are more damaging. There is no clear evidence of carcinogenicity in fibers < 10 μm long. For long fibers (>10 μm), chrysotile has lower risk for lung cancer than long fibers of amphibole. As the thickness decreases, the potency for the lung cancer is increased by both amphibole and chrysotile fibers. Amphibole
	Amphibole (general)	Length >10 μm and Thickness <0.2;<0.4;>0.2 μm	KL = 24.5 (7.6–66.3); KL = 7.7 (1.6–26.6); KL = 3.2 (0.71–14.0)
Pierce JS et al., 2008	Chrysotile	1.4–2.7 f/ml-y	SMR = 0.65 (0.28–1.43)	Most articles do not show an increased risk of lung cancer from high chrysotile exposures. Cross-contamination with other fibers should be considered. There was no increase in risk of lung cancer in the 4 highest exposure categories (≥112 fibers/cc-y), due to a possible confounding factor in smoking. In other studies, the risk increased from exposures >25-1600-3200 fibers/cc-y. in Cross-contamination with other fibers should be considered.
		414–942 f/ml-y	SMR = 1.05 (0.7–1.52)
			NOAEL for lung cancer: >25f/cc-y
Gamble J, 2008	Chrysotile	<15 f-y/ml; >40 f-y/ml	RR = 1.8 (0.8–3.9); 1.9 (0.5–7.1)
		<3 mppcf-y; >1000 mppcf-y	SMR = 1.12; SMR = 2.95 (2.18–3.96)
	Amphibole: amosite	<6 f/ml-y; >250 f/ml-y	SMR = 2.64; SMR = 11.7
	Mixed	<10 and >10 years exposed	SMR = 0.92; SMR = 1.41
Lenters V et al., 2011	Chrysotile	100 f-y/ml	KL = 0.04 (−0.05–0.12)	Applying formula RR = α (1 + KL × CE) where α is the rate for lung cancer with exposure 0, KL is the increment coefficient of RR per unit in fibers-y/ml and CE the accumulated exposures (if available for 10 years) can be obtained if α=1.47, KL =0.13, a metaRR = 1.66 (1.53–1.79) for each100 f-y/ml. RR = 1.013 (0.791–1.296) for 4 f-y/ml (fibers in general) RR = 1.133 (0.888–1.444 for 40 f-y/ml (fibers in general) Linear increase in risk of lung cancer at low levels of exposure. The slope decreases slightly from exposures to 150 f-y/ml. Increased risk of lung cancer from exposure to amphibole fibers, followed by mixed fibers and chrysotile.
	Amphiboles (General)	100 f-y/ml	KL = 0.33 (0.09–0.56)
	Mixed	100 f-y/ml	KL = 0.13 (0.03–0.23)
Van der Bij S et al., 2013	Chrysotile	4 f-y/ml −40 f-y/ml	RR = 1.006 (0.848–1.194); RR = 1.064(0.873–1.297)
	Amphibole (General)	4 f-y/ml −40 f-y/ml	RR = 1.022(0.568–1.837); RR = 1.232(0.687–2.209)
	Mixed	4 f-y/ml −40 f-y/ml	RR = 1.018(0.690–1.503); RR = 1.194(0.825–1.727)
Roggli V, 2015	Chrysotile	Length>5 μm,	RR and OR increase (not specified)	No clear evidence of carcinogenicity for amphibole fibers >10 μm and chrysotile ≤5 μm long. The length and durability of the fibers is what is most associated with the potency of carcinogenicity. Other non-asbestiform long fibers have also been associated with fibrosis and tumors.
	Amphibole: crocidolite	Length ≥10 μm	RR and OR increase (not specified)

^aExposure values from which the risk will be evaluated. The minimum and maximum range, if any, are detailed. The unit fiber-year/milliliter (f-y/ml), fibers/milliliter-year (f/ml-y), fibers-year/cubic centimeter (f-y/cc) and fibers/cubic centimeter-year (f/cc-y) are equivalent; General: fibers without exact measurement of exposure.

^bR_L: risk of lung cancer; excess risk of lung cancer risk per fiber/ml-year; equivalent to KL; RL = 100 (SMR-1)/Expos (f/ml-y).

^cDifferent RRs depending on the applied coefficient: following EPA models (RR = 1 + 0.01 cumulative exposure), Quebec mines (RR = 1 + 0.0006 accumulated exposure), industry (RR = 1 + 0.00025 accumulated exposure). The latter would be most appropriate for the indicated study. NOAEL: highest cumulative exposure level at which no effect was observed; RR: relative risk; OR: odds ratio; SMR: standardized mortality ratio. Some results have no confidence interval (95% CI).