Dear all,

Currently i'm working on a public paper in which I describe the use of
environmental tracers in subsurface hydrology. This paper is (logically)
based on the textbook of Cook and Herczeg. This book brilliantly gives a
overview of the use of tracers in hydrology. I only miss one point of
information, which is critical to convince the public(environmental
agencies and the water departments in the netherlands) of using them when
encountering hyrological problems. And these are the analytical prices. I
have to have a comparison between the advantances of the different tracers
and their prices.
So far I have found the prices for:
3H/3He
Kr-85
14C
3H
I'm still searching for the prices of the following radio-isotopes:

Cl-36
Ar-37
Ar-39
Rn 222
234U/238U
I-129
Si-32
Kr-81
S-35

and the prices of the tracers:
CFC
SF6

and the price:
Of a total noble gas analyses (only the stable isotopes).

Could anyone help me with this? If you know one of the above prices(on
scientific basis or economic basis. I know that some of the radioisotopes
are rather exotic and therefor expensive. But this doens't matter, I also
describe future chances of tracers in this paper. So allthough some
analyses are too expensive for practical use right now, it can be
affordable in the future when the technique becomes common good. Estimates
of future prices are very welcome in this perspective.  Please mail id you
can provide me with any information on prices(current and future prices).
Thanks in advance.

Sincerely Rik Jonker

Adjunct researcher at the free university of amsterdam