Clarification of Answer by
sublime1-ga
on
31 Dec 2002 12:53 PST
jigari...
As it turns out, there is an extensive (45 page) pdf file
available from the "Agency for Toxic Substances and Disease
Registry - U.S. Dept. of Health and Human Services" website,
which examines the movement of iodine in the environment,
and distinguishes between naturally-occurring and man-made
iodine:
http://www.atsdr.cdc.gov/toxprofiles/tp158-c6.pdf
"The average iodine content in seawater is 40–65 µg/L
(NRC 1979). The iodine content in rainwater averages
between 0.1 and 15 µg/L, and in rainwater over oceans,
the iodine content is 1–15 µg/L (NRC 1979). The iodine
content in river water averages between 0.1 and 18 µg/L
(NRC 1979). The concentration of iodine in river water
will be locally influenced by municipal waste water
streams. The average iodine content in municipal waste
water effluent is 4.0 µg/L (range 1.0–16 µg/L) (NAS 1974).
In groundwater, the average iodine concentration is 1 µg/L
(Yuita 1994a)."
As for iodine concentrations in drinking water:
"The iodine content in drinking water typically varies
between 0 and 8 µg/kg, with a more nominal range
averaging between 2 and 4 µg/kg. Concentrations of
iodine in drinking water approaching or exceeding
8 µg/kg are usually associated with water that is
directly contaminated with sewage or effluent from
sewage discharge sites or from urban run-off
(FDA 1974). For example, the concentration of iodine
in the Potomac River was 4.0 µg/L upstream of
Alexandria, but increased to 8.0 µg/L downstream.
Sewage effluent from Alexandria was believed to be
the cause." [Page 23, 6.4.2 Water]
"Iodine exists in many chemical forms (e.g., molecular
iodine, iodide, iodate, periodate) and can undergo
oxidation-reduction as well as microbial alkylation
(mostly methyl iodide). Iodine has nine radioisotopes,
of which 125I, 129I, and 131I are commonly encountered
in acute or chronic exposures to human populations,
due either to the life-times of the radioisotope in the
environment, their production, and/or their utilization
in industry, medicine, and research."
[page 1, 6.1 Overview]
There are maps, included in the file, which indicate
areas contaminated with iodine isotopes. Texas is not
among the states. See figures 6-1, 6-2 and 6-3.
"Releases of iodine into the environment occur from both natural
sources and human activity. The natural sources include
volatilization of iodine from the oceans, weathering of rock,
and volcanic activity (Cohen 1985; Whitehead 1984). Sources of
iodine from human activities include release of radioiodine from
nuclear weapons testing and nuclear fuel reprocessing, waste
stream effluent from municipal plants, and combustion of waste
and fossil fuels (Likhtarev et al. 1993; Moran et al. 1999;
NAS 1974; NCRP 1983; Stetar et al. 1993).".............
......"If precipitation occurs over land, iodine will be
deposited onto plant surfaces or soil surfaces, or into surface
waters....Retention of iodine in the soil is influenced by a
number of factors, including soil pH, soil moistness, porosity
of soil, and composition of organic and inorganic (e.g.,
aluminum and iron oxides) components (Sheppard et al. 1995;
Whitehead 1984). Approximately 1% of iodine received through
atmosphere-to-soil deposition is returned through volatilization
of molecular iodine and methyl iodide; the remaining iodine is
eventually returned to the oceans through surface water and
groundwater (NRC 1979; Whitehead 1984). The average residency
time of iodine in the soil at 0.3- and 1-meter depths has been
suggested to be 80 and 800 years, with only 1–3% of deposited
iodine migrating to the 1-meter depth (DOE 1986)."
[Page 5, 6.1 Overview]
"Transport of iodine through surface water and groundwater is
not greatly retarded by the soil, rock, and sediments over or
through which these waters flow (NRC 1981). The concentration
of iodine in river water ranges between 0.1 and 18 µg/L,
which parallels the concentration of iodine in rainwater of
0.1–15 µg/L (NRC 1979). In groundwater, the mean concentration
is 1 µg/L (Yuita 1994a). The concentration of iodine in river
water often increases downstream of urban areas due to the
discharge of waste streams from municipal treatment facilities.
This is especially true for 131I that enters sewage streams
from patients undergoing radioiodine therapies (Tubiana 1982;
UNSCEAR 2000). Slightly elevated concentrations of 129I have
been observed in surface water and groundwater near nuclear
fuel reprocessing facilities (Beals and Hayes 1995; DOE 1994)."
[Page 6, 6.1 Overview]
"Introduction of iodine into surface waters and groundwater
occurs predominately through rainwater for noncoastal land
regions and the combination of rainwater and ocean spray in
coastal regions (Figures 6-4 and 6-5). It is estimated that
1.0x1011 g/year of iodine is deposited onto land surfaces,
of which 8.1x1010 g/year enters surface waters and 1.5x1010
enters groundwater (NRC 1981). The iodine in rainwater is
derived from the transfer of iodine from the oceans to the
atmosphere (FDA 1974). Other natural releases of iodine into
surface waters and groundwater include the leaching of iodine
from the weathering of rock and volcanic activity
(Figure 6-5). It is estimated that rocks contribute between
1x109 and 1.6x1010 g/year depending on the iodine content of
the rock (0.5–8.8 ppm) (Cohen 1985). Volcanic activity can
add an estimated 1.2x109 g of iodine per year to the surface
environment, where the greatest contribution to the oceans is
due to undersea volcanic activity (Miyake and Tsunogai 1963;
NRC 1979)." [Page 13, 6.2.2 Water]
I hope that satisfies your interest in asking this question.
Please feel free to ask for further clarification, if needed.
You said:
"If you feel this job requires more of your time investement,
please, let me know so that I can raise the price accordigly."
While it is too late to raise the price of the question, since
it has been answered, it is now possible to tip a researcher,
if you feel that their response went beyond the value originally
assigned to the question. This is entirely up to you, and is
not necessary.
Best regards, and Happy New Year...
sublime1-ga
Searches done, via Google:
"inorganic iodine" groundwater
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22inorganic+iodine%22+groundwater
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