Table III-2.

Reference values corresponding to an individual excess lifetime risk of cancer

Substance	Individual excess lifetime risk of cancer		Reference value		Method of estimation	Year of estimation
Arsenic and inorganic arsenic compounds		10–3	3	μg/m3	Average relative risk model	'00
		10–4	0.3	μg/m3
Asbestos
chrysotile		10–3	0.15	fibers/ml	Average relative risk model	'00
		10–4	0.015	fibers/ml
containing asbestos fibers		10–3	0.03	fibers/ml
other than chrysotile		10–4	0.003	fibers/ml
Benzene		10–3	1	ppm	Average relative risk model	'97
		10–4	0.1	ppm
Ionizing radiation		(Table III-3)				'12
Nickel smelting dusts (as Ni)		10–3	10	μg/m3	Average relative risk model	'09
		10–4	1	μg/m3