Table 1.

Steps of exposure assessment.

Step	Exposure parametersa
1. Work process	Yes/No
2. Work process × occupation	Probability of exposure P_ti: 0—unexposed, 1 to 10%—possible, >10 to 50%—probable, and >50%—very probable Frequency of exposure F_ti: 1 to 5%—sporadic, >5 to 30%—occasional, >30 to 70%—regular, and >70%—continuous
3. Occupationb	$\mathrm{S}\mathrm{u}\mathrm{m}\mathrm{m}\mathrm{a}\mathrm{r}\mathrm{i}\mathrm{z}\mathrm{e}\mathrm{d}\mathrm{p}\mathrm{r}\mathrm{o}\mathrm{b}\mathrm{a}\mathrm{b}\mathrm{i}\mathrm{l}\mathrm{i}\mathrm{t}\mathrm{y}\mathrm{o}\mathrm{f}\mathrm{e}\mathrm{x}\mathrm{p}\mathrm{o}\mathrm{s}\mathrm{u}\mathrm{r}\mathrm{e}\mathrm{P}=1-\underset{i=1}{\prod ^{numbe{r}_{workprocesses}}}(1-P\mathrm{\_}{t}_i)$ (0—unexposed, 1 to 10%—possible, >10 to 50%—probable and >50%—very probable) $\mathrm{S}\mathrm{u}\mathrm{m}\mathrm{m}\mathrm{a}\mathrm{r}\mathrm{i}\mathrm{z}\mathrm{e}\mathrm{d}\mathrm{f}\mathrm{r}\mathrm{e}\mathrm{q}\mathrm{u}\mathrm{e}\mathrm{n}\mathrm{c}\mathrm{y}\mathrm{o}\mathrm{f}\mathrm{e}\mathrm{x}\mathrm{p}\mathrm{o}\mathrm{s}\mathrm{u}\mathrm{r}\mathrm{e}\mathrm{F}=1-\underset{i=1}{\prod ^{numbe{r}_{workprocesses}}}[1-(P\mathrm{\_}{t}_i\times F\mathrm{\_}{t}_i)]$ (1 to 5%—sporadic, >5 to 30%—occasional, >30 to 70%—regular, and >70%—continuous)
4. Temporal axis	Historical period of exposure: start and end years

^aEstimation per and all UFP chemical families.

^bIndustrial sectors were taken into account for certain occupations.