Question

A field worker is exposed to a xylene for a duration of 8 weeks at 40 hrs/wk. The concentration of xylene in the workplace is 40 μg/m3. The worker is inhaling air at a rate of 0.9 m3/hr. Assuming 70 kg body mass, the chronic daily intake (CDI) [mg/(kg-d)] during the period of exposure is most nearly.

Answer 1

The chronic daily intake during the period of exposure is most nearly 0.012 mg/kg day.

Step-by-step explanation:

Number of hours worker exposed to xylene =
`40 hr/week* 8 week = 320 hours`

The concentration of xylene in the workplace =
`40 \mu g/m^3`

The worker is inhaling air at a rate of
`0.9 m^3/hr`.

Amount xylene inhaled by worker in an hour :

=
`40\mu g/m^3* 0.9 m^3/hr=36 \mu g/hr`

Amount xylene inhaled by worker in 320 hours:

`36 \mu g/hr* 320 hr=11,520 \mu g=11,520* 0.001 mg=11.520 mg`

1 μg = 0.001 mg

Amount xylene inhaled by worker in 320 hours = 11.520 mg

1 day = 24 hours

Amount xylene inhaled by worker in 1 day:

`(24)/(320)* 11.520 mg=0.864 mg`

Assuming 70 kg body mass, the chronic daily intake of xylene :

`(0.864 mg/day)/(70 kg)=0.01234 mg/ kg day\approx 0.012 mg/ kg day`

The chronic daily intake during the period of exposure is most nearly 0.012 mg/kg day.