A 70-kg adult drinks 2L/d of water containing 0.1 mg/L of 1,1-dichloroethylene for 20 years. The oral potency factor is 0.6 kg-d/mg; the inhalation potency factor is 16.1 kg- d/mg; the oral reference dose (RfD) is 0.009 mg/kg-d. a. Find the hazard index for this exposure. Assume that the person is exposed 350 d/y. b. Explain the general meaning of the hazard index (e. g., does this number quantify a risk level