Example What is the maximum allowable concentration of a chemical for a hypothetical person (70 kg), who drinks 2 L of...
Example Chloroform is sometimes formed incidentally in drinking water plants. Suppose a 70 kg person drinks 2 L of water per day from water with 0.10 mg/L chloroform. Find the upper bound cancer risk for this person, and estimate the number of extra deaths caused in a city of 500,000 with this exposure risk. How does this compare with the cancer risk in the US, which is 189/100,000/year?
Question #1 (from Mihelcic). Assume an adult female who weighs 50 kg drinks 2 L of water every day and the absorption factor for the chemical of concern is 75 percent. The concentration of the chemical in the drinking water is 55 ppb. Determine the dose in mg/kg-day. Question #2 (from Mihelcic). Determine if exposure by oral ingestion to the chemicals xylene, toluene, arsenic, and hexavalent chromium poses a noncarcinogenic health risk. The chemical-specific reference doses (mg/kg-day) obtained from IRIS...
A 70-kg individual drinks 2 L/day of water containing 0.015 mg/L of tetrachloroethylene for 20 years. (a) Find the hazard quotient for this exposure. (b) Find the cancer risk. (c) If the individual drinks this water for 30 years instead of just 20, recomputed the hazard quotient and the cancer risk. A man works in an Aluminum smelter for 10 years. The drinking water in the smelter contains 0.015 mg/L arsenic and 0.80 mg/L methylene chloride. His only exposure to...
Water with 1.0 mg/L methylene chloride + 0.01 mg/L tetrachloroethylene), 70 kg adult drinks 2L/day for 30 years. What is hazard index? RfD = 0.060 for methylene chloride, RfD = 0.010 for tetrachloride 1 0.512 2 0.029 3 0.483 4 0.00029 q2) A test bottle (Blank) containing just seeded dilution water has its DO level drop by 1.1 mg/L in a five-day test. A 300-mL BOD bottle filled with 30 mL of wastewater and the rest seeded dilution water (this...
Un-ionized ammonia (NH3) is toxic to fish at low concentrations. If the maximum allowable concentration of NH3 in a river (CNH3) is 0.20 mg/L as N, what is the maximum concentration of ammonium ion (NH4+) allowed (CNH4+), in units of mg/L as N, when the river water pH is 9? The dissociation of ammonium ion in water has an equilibrium constant of pKa = 9.25 and is described by the reaction: NH4+ = NH3 + H+. Show units throughout the...
20/27OBLEM: Suppose drinking water contains 1 mg/l of toluene and 0.01 mg/l of tetrachloroethylene (C2C4). A 70 kg adult drinks 2 t/day of this water for 10 years. a) Assess HR and evaluate HR. Was this a safe level of exposure? b) C2C4 is a carcinogen. What would be the carcinogenic risk faced by a person drinking it. Would it be less than 106 (goal)? RfDtoluene 0.2 mg/kg.day RfDc:ci 0.0 mg/kg.day PFc.c 5.1 x 10-2 (mg/kg-day) 20/27OBLEM: Suppose drinking water...
1. Chloroform (CHCl3) has a Drinking Water standard concentration of 0.10 mg/L . a. What is this concentration expressed as parts per million (ppm)? b. Typical consumption Risk Analysis assumes the average human drinks 2.2 L/day for 70 years. How many grams of CHCl3 would the average human consume during a lifetime at the Drinking Water standard concentration? 2. The Air Quality Standard for sulfur dioxide (SO2) is 0.04 ppm. Express this as mg/m3 at 1 atm and 25oC.
Chloroform (CHCI3) has a Drinking Water standard concentration of 0.10 mg/L What is this concentration expressed as parts per million (ppm)? Typical consumption Risk Analysis L/day for 70 years. How many grams of CHCI3 would the average human 1. a. b. assumes the average human drinks 2.2 during a lifetime at the Drinking Water standard concentration? consume Find the Volume of 1 mole of an ideal gas at 1.2 atm and 80°C 2. The Air Quality Standard for sulfur dioxide...
methylphenidate (ritalin)is recommended 0.3-2 mg/kg/day. What is the maximum recommended dose per day in mg a child who weighs 66lb?
23. Calculate the ThOD for wastewater containing 40 mg/l. sucrose C.H0.1. (atomic weights: C: 12 H:1 0:16) a 192 b 180 40.0 42.7 d e 85.4 other, write you answer- 24. When drinking water is disinfected with chlorine, an undesired byproduct, chloroform (CHCb). may be formed. Suppose a 70-kg person drinks 2 L of water every day for 70 years with a chloroform concentration of 0.04 mg/L (the drinking water standard). Potency factor for chloroform- 6.1 x 10 (mg/kg-day) The...