A person $(70$ kg$)$ works in an aluminum smelter for $10$ years $($use for calculating AT$)$ at $5$ hrs per

day for $49$ weeks per year. The air in the smelter contains $0\mathrm{.}560\backslash$mu g$/$m$3$ lead and $0\mathrm{.}070\backslash$mu g$/$m$3$

benzene. This person$$s only exposure to these chemicals is in air at work. Use below standards:

IR $=0\mathrm{.}96$ m$3$

$/$hr

RR $=100\%$

ABS $=100\%$

ET $=5$ hr$/$day

TDIPb $=3\mathrm{.}57$ ug$/$kg d

RsDBz $=3\mathrm{.}4$ x $10-4$ mg$/$kg d

SFBz $=0\mathrm{.}029$ kg d$/$mg

$($a$)$ What is the hazard index HQ and RQ associated with this exposure?

$($b$)$ Does the HQ and RQ indicate this is a safe level of exposure?

$($c$)$ What is the incremental lifetime cancer risk $($ILCR$)$ for the person due solely to the air

he$/$she inhales at work and does it seem to be an acceptable risk according to USEPA and Health

Canada? Explain