University:
California State University, Northridge
Course:
ME 485 | Introduction to Environmental Engineering
Academic year:

2007
Views:

489

Pages:

2
Author:

Garnarolaoue

4. 15 Concentrations yielding acceptable risks: a . benzene. oral, 10-5risk, potency= 2.9xL0-2 (mg/kg-d)-1 Risk= CDI x Potency 10. 5 = C= 2L / d x C mg/L x3 50d/yr x3 0yr 2.9xIO•: x mg/kg - d 70kg x365d/yr x70yr I0· 5 x70 x3 65 x70 = -� 0. 03mg/ L _ 2 X 350 X. 30 X 2.9x.10 - b. trichloroethylene in air, risk10-6. inhalation potency 13xIQ-2: f 20 m 3 / d xC mg/m 3 x3 50d/yr x3 0 yr l. 3 xlf 1 x 70kg x3 65d/yr x70yr mg/kg - d 10· 0 x70 x 3 65 x70 ,, = _ 3 C= 6 6xl0--' mg/m 20x 350 x 30 x l.3xIO-10. 6 = c . benzene in air, risk 10-5, potency 2.9xio-2: 4.18 DDT in fish= C (mg/ L) x BCF (Ukg); from Table 4.12, BCF= 54,000Ukg Risk= CDI xPotency 0.020mg/L x54,000 L/kg x 0.002kg/d 034 x Risk = =0.01 70kg mg/kg-d 4. 23 Infiltration of 120m 3 /hr, 0.1mg BaP/cigarette,1cigarette per hour: a . Find the steady-state concentration Input rate= Output rate 1cig/hr x 0.1 mg/cig = 120m 3/hr xC mg/m 3 C = O. l/ 120 = 0.00083 mg/m 3 b. living for a year with a smoker. mo m� I day hr x365day 0.00083 �x20- x -- x8day 24hr m day =l.lxlO�mg/kg-d CDI = 70kg x365 d/yr x70 yr Risk= CDI x Potency= I. lxI0- 6mg/kg-d x 6.11 (mg/kg -d)-1= 7x10-6

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