Answer: the total chronic daily intake is 0.03296 mg/
kg.d
Explanation:
First of we have to determine the CDI due to ingestion of drinking water
so
CDI = (C x IR x EF x ED) / (BW x AT) let leave this as equation 1
where C is the concentration of the life time risk of drinking water(1.0mg/L)
ED is the risk dying per year((70),
EF is the number of days per year(365 day/year)
BW is the weight of body(65.4)kg
AT is the average tenure time of life(75years)
IR = 2.3 L/days
so we substitute
CDI₁ = (1(mg/L) x 2.3(L/day) x 365 x 70) / (65.4 x 365 x 75)
= 3.29 x 10⁻² mg/kg.d
next we determine the CDI due to dermal contact with water.
find the ingestion rate which is equal to the exposure time in hour/day.
IR = ET
(20 min/day) / (60 min/hour)
= 0.333 h/day
now lets substitute for CD1₂
1.0 mg/L for C , 0.333 h/day for m , 365 day/year for EF, 70 year for ED, 65.4 kg for Bw , and 75 year for AT
0.8 for submergence and 1.69m² for area of skin of adult female in our equation 1
CDI₂ = [(1 mg/1) × (1.69 m²) × (9.0 x 10⁻⁶(m/h)) × 0.333(h/day) x 365 x 70)) / (65.4 x 365 x 75)] × ( 0.8 x 10³ L/m³)
CDI₂ = 5.41 x 10⁻⁵ mg/kg.d
now we find the CDI due to inhalation during bath
we substitute 1.0 mg/L for C, 11.3m³/day for IR , 365 day/year for EF , 70 year for ED. 65.4 kg for BW , and 75 year for AT in our equation 1
CDI₃ = [( 1ug/m³ × 1mg/10³ug) x (11.3m³/day x 1day/24 hr) x 365 x 70)] / (65.4 kg x 365 x 75 )
= 6.71 x 10⁻⁶ mg/kg.d
finally we Calculate the total chronic daily intake value
CDI_total = CDI₁ + CDI₂ + CDI₃
we substitute
CDI_total = 3.29 x 10⁻² + 5.41 x 10⁻⁵ + 6.71 x 10⁻⁶
= 0.03296 mg/kg.d
so the total chronic daily intake is 0.03296 mg/
kg.d
