Table 1. Years of exposure weighted by probability and intensity equivalent to 1 year of cumulative exposure*.

Probability		Intensity			Duration
		Low	Medium	High
		Assigned weights			Years of exposure
10–50%	Low	0.3			3.5
50–90%	Medium	0.5	0.7		2.0	1.5
>90%	High	0.7	1.0	1.0	1.5	1.0	1.0

*Assigned weight × years of exposure  =  cumulative exposure.