**2.11 Application of the formulas for calculation of toxicokinetic parameters of lead**

The reported LD50 of lead in human is 450 mg/kg body weight, but LD1 = 450/ 50 = 9 mg/kg body weight

i. LT50(d) LD50 *DP* <sup>¼</sup> <sup>450</sup> 91 3 <sup>¼</sup> <sup>450</sup> <sup>2</sup>*:*<sup>06</sup> <sup>¼</sup> <sup>218</sup>*:*<sup>4</sup> 24 h 9.1 days

However, for an adult man weighing 60 kg, the ED50 for lead antidote is calculated as follows:

ii. (ED50) LD50 <sup>3</sup> � *Wa* � <sup>10</sup>�<sup>4</sup> (ED50) <sup>450</sup> <sup>3</sup> � 60, 000 � <sup>10</sup>�<sup>4</sup> (ED50) 150 � 6 ¼ 900

ED1 <sup>90</sup> <sup>50</sup> ¼18 mg/kg of antidote

iii. Using dose rate (DR) = TC � Cl

\*\*1080 = 0.037 \times Cl

\*\*Cl =  $\frac{1080}{0.037} = 29189.2 \text{ kg/h.}$ 

\*\*29189.2 \times 1 = 1.24 l/kg/h.

At concentration of lead = 525 μg/dl. If LD1 = 9 mg/kg. Dose of lead for 60 kg man = 60�9 = 540 mg iv. (Vd=) Dose Concentration Vd = <sup>540</sup> <sup>525</sup> = 1.028 = 1.03 l/kg v. AUC = Dose Clearance 450 <sup>1</sup>*:*<sup>24</sup> = 362.9 mg/kg/h vi. β = *Clb Vd* = <sup>1</sup>*:*<sup>24</sup> <sup>1</sup>*:*<sup>03</sup> = 1.20 h. vii. MRT = *Vd Clb* = <sup>1</sup>*:*<sup>03</sup> <sup>1</sup>*:*<sup>24</sup> = 0.83 h. viii. T½β = <sup>0</sup>*:*<sup>693</sup> *<sup>β</sup>* = <sup>0</sup>*:*<sup>693</sup> <sup>1</sup>*:*<sup>20</sup> = 0.58 h.
