Civil Engineering homework help

/in /by

Spring 2021

CEE 422/522 Site Remediation

 

Assignment #2

 

(a) What is IRIS (Google the word IRIS EPA). Using IRIS, for Toluene, find

(a) oral reference dose of Toluene

(b) critical effect

(c) the value of uncertainty factor and explain why (i.e,. the basis of 3,000)

(d) summarize the findings of principal study

(e) List the supporting studies (i.e., provide the references)

 

(b) Using IRIS, for chloroform, find

(a) oral reference dose of Toluene

(b) critical effect

(c) carcinogenicity

(d) summarize the findings of principal study

(e) List the supporting studies (i.e., provide the references)

 

  1. You have 50,000 kg of hazardous waste in drums that requires disposal within the next 30 days. A disposal contractor, whom you know to be reliable, has quoted a disposal cost of $2.10/kg.  Another disposal contractor, who has had a number of EPA violations over the past year, has quoted a disposal cost of $0.90/kg. Which disposal contractor would you select, based on a risk assessment of the two alternatives?

 

  1. Define (a) LOAEL, (b) NOAEL and (c) LD50.

 

  1. Define carcinogens. Contrast mutagenesis, teratogenesis and carcinogenesis.

 

  1. Download and install IEUBK model from EPA website (works for windows only). Use the model to evaluate the impact of 650 ppm of lead concentration in children in a residential scenario. [Impact means geometric mean, % of children above 5 mg/dL and the distribution curve]

 

  1. Go to www.atsdr.cdc.gov

Then find the link TOXFAQs on the page and answer the following (read/review and cut and paste)

 

(a) What is benzene?

(b) What happens to benzene when it enters the environment?

(c) How might I be exposed to benzene

(d) How can benzene affect my health?

(e) How likely is benzene to cause cancer?

(f) How can benzene affect children?

(g) How can families reduce the risks of exposure to benzene?

(h) Is there a medical test to show whether I’ve been exposed to benzene?

 

  1. What is a biomarker (related to contaminant exposure). What is the name of the biomarker for benzene?

 

  1. The city of Annapolis disinfects its water supply using chlorine. If 50 mg/L of chloroform is being produced (and people are exposed to that concentration), estimate the chronic daily intake (mg/kg-day). State your assumptions, if any.

 

  1. One gram per day of dioxin is leaking into a 40,000 m3 pond. Assuming complete instantaneous mixing, what would be the concentration after one week (assume no loss in air or sediment).

 

  1. In the US, the generators are responsible for hazardous waste they create from “cradle to grave”. Explain what is meant by the phrase. Is the responsibility ends at the “grave”?