This topic contains a solution. Click here to go to the answer

Author Question: In a record from 12,370 carbon-14 years before the present to the present time, Ref. 59 finds that ... (Read 73 times)

Mollykgkg

  • Hero Member
  • *****
  • Posts: 529
In a record from 12,370 carbon-14 years before the present to the present time, Ref. 59 finds that there was a decreasing lead-206/lead-207 ratio in deposited lead starting 3000 carbon-14 years ago. This is an indicator of lead mining.
 
  a. If the pre-anthropogenic deposition rate is 0.01 milligram per square meter per year, andthe highest rate found was 15.7 milligrams per square meter per year in 1979, determine therelative effect of humans in 1979
 b. How much more lead is being used in 1979 relative to 100, if the deposition in the year
  100 were 0.12 milligrams per square meter per year?

Question 2

Industrial wastes are more difficult to process for energy than municipal wastes.
 
  What will be an ideal response?



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

asdfasdf

  • Sr. Member
  • ****
  • Posts: 339
Answer to Question 1

a. The size of the effect must be proportional to the exposure. The relative effect is
equal to the relative exposure: 15.7 mg/0.01 mg = 1570 . Presumably, we modern humans
have a poisoning effect from lead about 1600 times as great as the effect on our ancestors
(these appears to be no lower threshold to the damage done; any lead exposure that can be
measured apparently causes damage).
b. In the year 100, humans were using lead at a rate far above natural releaseby a factor of

Answer to Question 2

Industrial wastes are more likely to be contaminated by metals and lubricants than
municipal wastes.




Mollykgkg

  • Member
  • Posts: 529
Reply 2 on: Jul 28, 2018
Wow, this really help


scottmt

  • Member
  • Posts: 322
Reply 3 on: Yesterday
:D TYSM

 

Did you know?

The U.S. Preventive Services Task Force recommends that all women age 65 years of age or older should be screened with bone densitometry.

Did you know?

There are immediate benefits of chiropractic adjustments that are visible via magnetic resonance imaging (MRI). It shows that spinal manipulation therapy is effective in decreasing pain and increasing the gaps between the vertebrae, reducing pressure that leads to pain.

Did you know?

Many supplement containers do not even contain what their labels say. There are many documented reports of products containing much less, or more, that what is listed on their labels. They may also contain undisclosed prescription drugs and even contaminants.

Did you know?

The newest statin drug, rosuvastatin, has been called a superstatin because it appears to reduce LDL cholesterol to a greater degree than the other approved statin drugs.

Did you know?

There are approximately 3 million unintended pregnancies in the United States each year.

For a complete list of videos, visit our video library