Study: The atmospheric transport of iodine-129 from Fukushima to British Columbia, Canada and its deposition and transport into groundwater

“…dilution and dispersion have reduced 129I contamination as further inputs have ceased.”

Where are the authors getting their information on Fukushima?

From American Geophysical Union
Water Resources Research  Journal

First published: 17 December 2015
DOI: 10.1002/2015WR017325


The Fukushima-Daiichi nuclear accident (FDNA) released iodine-129 (15.7 million year half-life) and other fission product radionuclides into the environment in the spring and summer of 2011. 129I is recognized as a useful tracer for the short-lived radiohazard 131I, which has a mobile geochemical behavior with potential to contaminate water resources. To trace 129I released by the FDNA reaching Canada, pre-accident and post-accident rain samples collected in Vancouver, on Saturna Island and from the National Atmospheric Deposition Program in Washington State were measured. Groundwater from the Abbotsford-Sumas Aquifer was sampled to determine the fate of 129I that infiltrates below the root zone. Modeling of vadose zone transport was performed to constrain the travel time and retardation of 129I. The mean pre-accident 129I concentration in rain was 31 × 106 atoms/L (n = 4). Immediately following the FDNA, 129I values increased to 211 × 106 atoms/L and quickly returned to near-background levels. However, pulses of elevated 129I continued for several months. The increases in 129I concentrations from both Vancouver and Saturna Island were synchronized, and occurred directly after the initial release from the FDNA. The 129I in shallow (3H/3He age <1.4 years) Wassenaar et al. (2006) groundwater showed measurable variability through March 2013 with an average of 3.2 × 106 atoms/L (n = 32) that was coincident with modeled travel times for Fukushima 129I. The groundwater response and the modeling results suggest that 129I was partially attenuated in soil, which is consistent with its geochemical behavior; however, we conclude that the measured variability may be due to Fukushima 129I entering groundwater.

Continue reading


Study overview – Tracking the Fallout and Fate of Fukushima Iodine-129 in Rain and Groundwater

He minimizes the impacts of the fallout, but the charts are telling and contradict some of his statements. This is increased and increasing exposure of a near-permanent element that is toxic. It is getting into aquifers and drinking water rapidly. Plus it is only one radioisotope. How many hundreds more accompanied iodine-129, and into the groundwater as well? What is the total rad amount that we are drinking and breathing?

Posted by Matt Herod, co-author of University Ottawa study

The atmospheric transport of iodine-129 from Fukushima to British Columbia, Canada and its deposition and transport into groundwater

December 21, 2015

A recently published paper (by myself and colleagues from uOttawa and Environment Canada) investigates the environmental fate of the long lived radioisotope of iodine, 129I, which was released by the Fukushima-Daichii Nuclear Accident (FDNA). Within 6 days of the FDNA 129I concentrations in Vancouver precipitation increased 5-15 times above pre-Fukushima concentrations and then rapidly returned to background. The concentrations of 129I reached were never remotely close to being dangerous, however they were sufficient to distinguish the impact of the FDNA on the region.

Subsequent sampling of groundwater revealed slight increases in 129I concentration that were coincident with the expected recharge times. This suggests that a small fraction of the FDNA-derived 129I may have been transported into local groundwater after infiltrating through soils.


Sample map showing location of all three precipitation sampling locations as well as the location of both wells used for groundwater sampling. The surface expression of the Abbotsford-Sumas Aquifer is shaded.

What is iodine-129 and where does it come from?

Iodine-129 is the longest lived isotope of iodine with a half-life of 15.7 million years. It is radioactive and occurs everywhere throughout the environment. It is produced in three ways. The first two are natural and the third is by the nuclear industry.

The natural production of 129I occurs in the atmosphere and in soil/rocks. The atmospheric production happens when a cosmic ray proton hits a xenon-129 nucleus and removes a neutron, replacing it and creating an iodine-129 nucleus. The production in soil and rocks happens when a uranium-238 nucleus spontaneously fissions and one of the halves it releases has a mass of 129 ala, iodine-129.

The anthropogenic production occurs because when uranium fissions in a nuclear reactor sometimes one of the parts is 129I. This anthropogenic production is by far the largest source in the environment as substantial amounts have been released by nuclear fuel reprocessing. This 129I that has been released can trace a host of environmental processes and inform us about what happens to 129I or the much more dangerous, 131I. The current levels of 129I are much too low to pose a health threat to humans or the environment, but do allow 129I to be used as an environmental tracer.

129I from Fukushima is present in Vancouver, B.C. rain

The purpose of this research was to discover the fate of 129I in the released by Fukushima, which although a small amount, was isolated in time and space. We measured the 129I deposition in rain and its subsequent movement though soils and see if it reached groundwater. The results tell us about the impact of Fukushima, how 129I moves, where it is attenuated, and how quickly contaminants in this aquifer move from the ground surface to the water table. This knowledge can then be applied to understand 129I behavior in other settings such as nuclear waste repositories and watersheds or it can be used to learn about the behavior of other types of contaminant in this aquifer and how vulnerable it is to contamination.

The results in rain show an increase in 129I concentrations of up to 220 million atoms/L*. This increase was seen ~6-10 days after the emission from Fukushima began and are 5-15 times higher than rain samples collected before Fukushima. Following this increase 129I concentrations returned to background with a few weeks. This agrees with other studies monitoring the fallout of Fukushima derived radioisotopes [Wetherbee et al., 2012]. Furthermore, atmospheric back trajectory modelling shows trajectories for air parcels arriving in Vancouver from over the Pacific ocean and Japan.


[Editor: Note that 129I is still spiking in February 2012, (top chart) and could be trending toward another spike, when the data stops]

Variation in the concentration of 129I and the 129I/127I ratio in precipitation from Vancouver, Saturna Island and NADP site WA19 over time. The time range that each NADP sample integrates is displayed using horizontal error bars. 1σ error is contained within data points if not visible. The dashed vertical line shows the date of the FDNA relative to samples.

We also calculated the mass flux of 129I from Fukushima. That is the actual quantity of 129I that was deposited on the region in grams, or in this case in atoms/m2. This was calculated by simply multiplying the concentration of 129I in rain by the amount of rain that fell. We found that only about 15% of the annual 129I deposition in the Vancouver region could be directly linked to Fukushima affected rain events. The total mass deposited by Fukushima was ~0.0000000000002 (2 x 10^-13) grams. This is a negligibly small quantity with respect to radioactive risk.

Despite the fact that the deposition of 129I from Fukushima was infinitesimally small it was still measurable. Therefore, the question became where did it go and can we learn about local groundwater resources using 129I as a tracer?

129I variation in groundwater may be due to Fukushima

The results in groundwater show very small 129I concentration increases. Two different wells were sampled. The first had a recharge time, which is the time it takes for water to move from the water table to the well screen, where it is sampled, of 0.9 years and the second had a recharge time of 1.2 years [Wassenaar et al., 2006]. The exact time it takes for water and dissolved contaminants to travel through the unsaturated zone was unknown. However, the sediments of this aquifer are very coarse and are known for their ability to rapidly transport contaminants, such as nitrate [Chesnaux and Allen, 2007]. Therefore, if we were going to see 129I from Fukushima this was an ideal location.

The increases in groundwater 129I concentrations were seen in two different wells (ABB03 and PB20) located close to one another. The two wells also had slightly different recharge times. The first was 0.9 years and the second was 1.2 years. The 129I anomaly in the first well occurred at 0.9 years and in the second well at 1.2 years. These 129I anomalies, which occurred exactly when the recharge age predicted they would, suggests that some of the 129I deposited by Fukushima was reaching the wells and causing these increases.


Temporal variation in the concentration of 129I in groundwater in ABB03 and PB20. The solid vertical line shows the date of the Fukushima accident and the dashed horizontal line shows the median of each dataset respectively. The 3H/3He ages from [Wassenaar et al., 2006] of groundwater in each well and their uncertainty is pictured as the solid arrow which is aligned with the 129I anomaly possibly caused by the FDNA. The dashed arrow covers a 40 day (0.11 year) time span and represents a possible vadose zone transport time.

In order to verify if it was possible for 129I to travel from the ground surface to the water table in the time required to produce the variations observed we modelled its transport time and attenuation through the unsaturated zone.

The time it took for 129I to reach the water table in the model was then added to the previously dated recharge time to get an estimate for how long it might take 129I from Fukushima to reach the wells we sampled. The results show that it is indeed possible for 129I deposited in rain to infiltrate through the unsaturated zone and reach the wells in time for us to detect it. However, this rapid transport assumes that certain flow paths exist to rapidly conduct 129I due to the heterogeneous lithology of the unsaturated zone. There is evidence of such flow paths [McArthur et al., 2010].

To summarize,

  • Within a week of the FDNPP accident elevated 129I concentrations were observed in precipitation. This agrees very well with work on other radionuclides in air filters and rain.
  • 129I concentrations in rain returned to background within a few weeks. However, discrete pulses of elevated 129I occurred for another several months.
  • Elevated 129I concentrations were measured in two wells and corresponded with the expected recharge times indicating that 129I from Fukushima can be traced into groundwater.
  • Vadose zone modeling has shown that 129I can be rapidly transported to the water table and reach the well screen in accordance with groundwater ages.
  • We propose 129I transport is enhanced by preferential dispersion of 129I that exists due to the heterogeneous nature of the vadose zone.
  • This results in variability in groundwater 129I concentrations that preserve the variability in the input of 129I via washout with some dampening of the signal due to attenuation and dilution.

Fukushima Model

Conceptual model showing the possible transport pathways of Fukushima derived 129I which was deposited via precipitation. A fraction of this 129I was rapidly transported through a heterogeneous vadose zone via preferential flowpaths to groundwater where minor 129I variation was detected. The remainder was retarded or attenuated in the vadose zone during transport.

Thanks for reading, if you have any questions or concerns please leave a comment or send me an email to discuss further!

*Note: 100 million atoms/L of 129I is equivalent to an activity of 0.00000014 (1.4 x 10^-7) Bq/L. These quantities are extremely low level and only the most sensitive analytical methods in the world can detect them. This amount of radioactivity is several orders of magnitude lower than the natural background radiation produced by naturally occurring radionuclides in soil and the atmosphere. For more on naturally occurring radioactivity see here. Even a clean rainfall has about 1 Bq/L of tritium (radioactive hydrogen), which remains from atmospheric weapons testing in the 1960’s

Access the full paper here:


Chesnaux, R., and D. M. Allen (2007), Simulating Nitrate Leaching Profiles in a Highly Permeable Vadose Zone, Environ. Model. Assess., 13(4), 527–539, doi:10.1007/s10666-007-9116-4.

McArthur, S. A. Q., D. M. Allen, and R. D. Luzitano (2010), Resolving scales of aquifer heterogeneity using ground penetrating radar and borehole geophysical logging, Environ. Earth Sci., 63(3), 581–593, doi:10.1007/s12665-010-0726-9.

Wassenaar, L. I., M. J. Hendry, and N. Harrington (2006), Decadal geochemical and isotopic trends for nitrate in a transboundary aquifer and implications for agricultural beneficial management practices., Environ. Sci. Technol., 40(15), 4626–32.

Wetherbee, G. A., D. A. Gay, T. M. Debey, C. M. B. Lehmann, and M. A. Nilles (2012), Wet Deposition of Fission-Product Isotopes to North America from the Fukushima Dai-ichi Incident, March 2011, Environ. Sci. Technol., 46(5), 2574–2582.


Matt Herod is a Ph.D Candidate in the Department of Earth Sciences at the University of Ottawa in Ontario, Canada. His research focuses on the geochemistry of iodine and the radioactive isotope iodine-129. His work involves characterizing the cycle and sources of 129I in the Canadian Arctic and applying this to long term radioactive waste disposal and the effect of Fukushima fallout. His project includes field work and lab work at the André E. Lalonde 3MV AMS Laboratory. Matt blogs about any topic in geology that interests him, and attempts to make these topics understandable to everyone. Tweets as @GeoHerod.

Tracking the Fallout and Fate of Fukushima Iodine-129 in Rain and Groundwater

Posted under Fair Use Rules.

– Iodine 129 and 131: what are the hazards?

From Dr.
Posted 9-2-13

U.S. Nuclear Regulatory Commission (NRC) officials calculated an annual thyroid dose of 40,000 microsieverts (or 4 REM) for infants under one year of age in California. Per the U.S. Department of Health and Human Services division of Radiation Emergency Medical Management division (REMM), a child’s dose of 5 REM is immediate grounds for evacuation and prophylactic measures. (REM does not specifically reference an infant dose) Thus, the projected government dose of 4 REM was 80% of the suggested evacuation rate.

Iodine-131, a radioactive isotope, is primarily taken up by the thyroid gland. It is a bio-mimicker. The thyroid gland requires iodine to function. In a nuclear accident large amounts of radioactive iodine-131 are released and this was certainly the case for Fukushima, especially in the early days. The thyroid gland is unable to differentiate between regular iodine and radioactive iodine and will uptake whatever chemical form it is presented with especially when one is already iodine deficient.

The negative health consequences of iodine-131 target the sensitive populations of the pregnant, unborn, babies and children up to 10 years of age most aggressively. If iodine-131 is inhaled or ingested it lingers in the body wherein it emits radioactive energy that results in internal damage mainly to the thyroid and parathyroid glands. According to the EPA iodine-131’s short half-life of 8 days means that it will decay away completely in the environment in a matter of months but with devastating affects to the thyroid tissues if those tissues are deficient in iodine.

Unborn, infants and children have tiny thyroid glands and an overall small body mass. Thus when ingested, a particle of iodine-131 can direct tremendous and damaging energy at cells at a much greater ratio than in an adult.
Critical uptake facts[1] per the Agency for Toxic Substances and Disease Registry

  • Newborn babies will uptake iodine at rates 16 times higher than adults.
  • Infants under the age of one have an eight times higher uptake than adults.
  • Five-year-old children have four times the adult uptake rate.
  • Pregnant mothers have increased thyroid uptake, most noted in the first trimester.
  • The unborn have an increased thyroid uptake in the second and third trimester of pregnancy.
  • Nursing mothers can secrete 25% of iodine reserves to their babies.

Dr. Brownstein said, “After testing individuals and finding low iodine levels, I began to use smaller milligram amounts of iodine/iodide (6.25 mg/day). Upon retesting these individuals 1-2 months later, little progress was made. I therefore began using higher milligram doses (6.25-50 mg) to increase the serum levels of iodine. It was only with these higher doses that I began to see clinical improvement as well as positive changes in the laboratory tests.”

Dr. Michael B. Schachter says, “The treatment dose when a person is iodine insufficient is generally between 12.5 mg and 50 mg daily. Preliminary research indicates that if a person is iodine insufficient, it takes about three months to become iodine sufficient while ingesting a dosage of 50 mg of iodine and a year to become iodine sufficient while ingesting a dosage of 12.5 mg of iodine daily. However, the patient needs to be monitored closely with awareness of possible side effects and detoxification reactions.”

Iodine and Cancer

High intake of iodine is associated with a lower risk of breast cancer. Low iodine intake is associated with liver cancer.2] Women with a history of low iodine levels (hypothyroidism) face a significantly higher risk of developing liver cancer. [Researchers led by Manal Hassan of Anderson Cancer Center at the University of Texas concluded that this finding suggested a clinical association between hypothyroidism and hepatitis C, which is contributing to the country’s rising rate of liver cancer.

Dr. Michael Friedman says, “Women are particularly at risk due to environmental agents depleting iodine reserves and other agents exposing them to radioactive 1-131. After the thyroid gland, the distal portions of the human mammary glands are the heaviest users/concentrators of iodine in tissue. Iodine is readily incorporated into the tissues surrounding the mammary nipples and is essential for the maintenance of healthy functioning breast tissue. The radioactive decay of 1-131 in breast tissue may be a significant factor in the initiation and progression of both breast cancer and some types of breast nodules.”

The Journal of Nuclear Science and Technology Volume 50, Issue 3, 2013 contains a paper titled Source term estimation of atmospheric release due to the Fukushima Dai-ichi Nuclear Power Plant accident by atmospheric and oceanic dispersion simulations. Using the best available data and models it provides new estimates for the total quantity of I-131 and Cs-137 that was released into the atmosphere by the events at Fukushima Dai-ichi during the period from March 12 – March 20, 2013.[3] This report shows that the total amounts of I-131 and Cs-137. discharged into the atmosphere from 5 JST (Japan Standard Time)  on March 12 to 0 JST on March 20 were estimated to be approximately 2.0 × 1017 and 1.3 × 1016 Bq, respectively.

Iodine -129 – A Growing Radiological Risk

While we’ve all been led to believe that I-131 is no longer so much of a threat from Fukushima, we have to also worry about the effects of another type of iodine and that’s I-129. I-129 is another isotope produced by the fission of Uranium-235. Within these fission products approximately 75% is I-131 and 25% is I-129. Iodine-129, although a result of nuclear fission in reactors, also occurs to a small extent in the upper atmosphere due to the interaction of high-energy particles with naturally-occurring xenon. Iodine-129 has a long half-life of ~15.7 million years, which makes this of significant concern when processing nuclear waste or when nuclear accidents occur.

According to the Environmental Protection Agency when I-129 or I-131 is ingested, some of it concentrates in the thyroid gland. The rest passes from the body in urine. Airborne I-129 and I-131 can be inhaled. In the lung, radioactive iodine is absorbed, passes into the blood stream, and collects in the thyroid. Any remaining iodine passes from the body with urine.

In the body, iodine has a biological half-life of about 100 days for the body as a whole. It has different biological half-lives for various organs: thyroid – 100 days, bone – 14 days, and kidney, spleen, and reproductive organs – 7 days. Long-term (chronic) exposure to radioactive iodine can cause nodules, or cancer of the thyroid.

Iodine-129 and -131 experience beta decay, which means they emit beta particles when decaying from unstable to stable form. Beta particles are moderately energetic. Gamma rays are also emitted and are highly energetic, which means that they can be detected outside the body, for example, when uptake in the thyroid is measured by external sensors. Beta particles easily pass through soft tissue and cause damage to DNA by literally shattering DNA strands and knocking out chunks of gene sequences. What makes them potentially dangerous is the localized accumulation in the thyroid.

“Due to its long half-life and continued release from ongoing nuclear energy production, Iodine-129 is perpetually accumulating in the environment and poses a growing radiological risk,” the authors of a study at Dartmouth point out.[4]

The production rate of these two isotopes in a nuclear reactor occurs at a fixed ratio of 3 parts iodine-131 to one part iodine-129. The two substances travel together, so the presence of the easily detectable isotope also signals the presence of the longer-lived one. “If you have a recent event like Fukushima, you are going to have both present. The iodine-131 is going to decay away pretty quickly over the course of weeks, but the iodine-129 is there forever, essentially,” Joshua Landis, a research associate in the Department of Earth Science at Dartmouth explains, “Once the iodine-131 decays, you lose your ability to track the migration of either isotope.”

In a news report by the Pacific Standard we see that there is now no remediation technology available for the significant quantities of iodine-129 that have already leaked into groundwater at nuclear weapons production locations, including the Hanford Site in Washington state. Meanwhile, France and England — which produce large proportions of their electricity via nuclear power — are reprocessing spent fuel and disposing of vast quantities of iodine-129 simply by dumping it in the ocean.

Ocean disposal of iodine-129 appears to have resulted in massive increases of radionuclide concentrations. Currents carry the British and French iodine-129 northward, and a 2003 Danish study found concentrations in the Kattegat strait between Denmark and Sweden increased six fold between 1992 and 2000. Concentrations of iodine-129 in some Arctic waters are 4,000 times their pre-nuclear era levels. Add to this the I-129 released from Fukushima and we should be aware that there is much to be concerned with.


Every parent needs to come to the conclusion that they need to supplement with iodine at reasonably high levels. The situation is bad and destined to get worse. If one waits for their doctors or government officials to give out warnings one will sooner or later regret it.


[2] Hassan, Manal et al; Association Between Hypothyroidism and Hepatocellular Carcinoma: USA Case-Control Study. Hepatology, May 2009

[3] Source term estimation of atmospheric release due to the Fukushima Dai-ichi Nuclear Power Plant accident by atmospheric and oceanic dispersion simulations; Takuya Kobayashia, Haruyasu Nagaia, Masamichi Chinoa & Hideyuki Kawamuraa ;Journal of Nuclear Science and Technology;Volume 50, Issue 3, 2013; pages 255-264;

[4] Dartmouth scientists track radioactive iodine from Japan nuclear reactor meltdown; Dartmouth College; April 2, 2012

Dr. Mark Sircus, Ac., OMD, DM (P)

Director International Medical Veritas Association
Doctor of Oriental and Pastoral Medicine

Posted under Fair Use Rules.

– Vancouver rainfall had 220,000,000 atoms per liter of Iodine-129 after Fukushima; half-life = 15.7 million years; rapidly reached drinking water aquifer

From ENE News
Posted February 17, 2016

Matt Herod, Univ, of Ottawa Ph.D Candidate, Dec 21, 2015 (emphasis added): A recently published paper (by myself and colleagues from uOttawa and Environment Canada) investigates… [Iodine-129] which was released by the Fukushima-Daichii [sic] Nuclear Accident… Within 6 days of the FDNA 129I concentrations in Vancouver precipitation increased 5-15 times… sampling of groundwater revealed slight increases in 129I… The results in rain show an increase in 129I concentrations of up to 220 million atoms/L… 129I anomalies [in groundwater wells], which occurred exactly when the recharge age predicted they would, suggests that some of the 129I deposited by Fukushima was reaching the wells… [P]ulses of elevated 129I occurred for another several months. Elevated 129I concentrations were measured in two wells… indicating that 129I from Fukushima can be traced into groundwater… [M]odeling has shown that 129I can be rapidly transported to the water table

Scientists from Univ. of Ottawa’s Dept. of Earth Science and Environment Canada (Government of Canada), Dec 2015: The atmospheric transport of iodine-129 from Fukushima to British Columbia, Canada and its deposition and transport into groundwater

  • The Fukushima-Daiichi nuclear accident (FDNA) released iodine-129 (15.7 million year half-life)… The mean pre-accident 129I concentration in rain was [31,000,000 atoms/L]… following the FDNA, 129I values increased to [211,000,000 atoms/L]… [P]ulses of elevated 129I continued for several months
  • The 129I in shallow… groundwater showed measurable variability through March 2013 with an average of [3,200,000 atoms/L]… coincident with modeled travel times…
  • Radionuclides released from the FDNA have been detected across the globe… [R]eleases of 129I and 131I… travel great distances
  • The Abbotsford-Sumas Aquifer… spans the Canada–U.S. border between [B.C., Canada and Washington, US] and supplies ∼120,000 people with drinking water
  • A pulse of 129I in precipitation with maximum concentrations of [211,000,000 atoms/L] in Vancouver and [221,000,000 atoms/L] at Saturna Island was observed 6 days following the FDNA. A value of [311,000,000 atoms/L] was also measured during the first week of July…
  • The high 129I concentrations while the FDNA was ongoing are attributed to the rapid trans-Pacific transport of 129I from Fukushima… This response in 129I concentrations shows that radionuclides from Fukushima were transported rapidly from Japan to the west coast of Canada and the US… [Sampling from Washington State], which is a composite of rainfall events spanning 15 March 2011 to 16 April 2011 shows a significantly elevated 129I concentration of [95,000,000 atoms/L]…
  • There was a spike in 129I concentration observed in the precipitation sample from the period of 1 July 2011 to 8 July 2011 [which] rose to [311,000,000 atoms/L]… a substantially higher concentration than any other sample… As monitoring at Fukushima detected no pulse of 129I in precipitation in July… this spike is likely due to a… nuclear fuel reprocessing facility. Modeling of the air parcel back trajectories… for the sampling period shows air mass trajectories from Hawaii, north Japan, and Russia…
  • The initial increase in 129I concentration at the water table appeared within ∼95 days, with a maximum concentration of [10,500,000 atoms/L]…
  • In the model cases, 129I reached the water table very rapidly
  • Groundwater 129I concentrations in two nearby wells showed minor anomalies over the sampling period which could be due to rapid infiltration of the FDNA atmospheric 129I signal… [M]odeling shows that it was possible for a component of the 129I deposited by the FDNA to be conducted rapidly from the ground surface to the water table… We conclude that it is possible that a fraction of 129I from the FDNA is transported conservatively in this aquifer via preferential flow paths to the water table…

See also: Official in Canada advises public not to drink rainwater coming from Fukushima

And: Rain with 20,000,000 particles of Iodine-131 per liter fell on US (VIDEO)