Three Mile Island

Counsel: Can you state your name for the record?

Kozubov: Gennady Kozubov

Counsel: What is your profession?

Kozubov: I am a merited Chief Scientific Worker-Advisor.

Counsel: And where do you work?

Kozubov: I conduct my research at the Institute of Biology in the Komi Science Center which is

under the Ural Division of the Russian Academy of Science. I am also a member of

the International Union of Radioecologists.

Counsel: Are you prepared to state your expert opinion about the effects of radiation exposure on

pine and spruce wood from Three Mile Island?

Kozubov: Yes, I am.

Counsel: First off, can you tell us about your education?

Kozubov: I have a doctorate in Biological Sciences which I obtained in 1971 from the Komarov

Botanical Institute in Ukraine.

Counsel: Can you briefly describe your area of expertise?

Kozubov: I specialize in the biology of coniferous arboreal plants where I've conducted

morphophysiological and radiobiological investigations.

Counsel: What is radiobiology?

Kozubov: It is a branch of biology that studies the effects of radiation on organisms.

Counsel: Can you list any radiobiological investigations that you've conducted?

Kozubov: I've conducted radiobiological investigations of arboreal plants in the Chernobyl (sure - no - bull) NPS

accident region. One of my recent monographs covers this investigation focusing on

radiational effects on coniferous (con - ni - fur - us) forests.

Counsel: Can you tell the jury about your other publications?

Kozubov: I've published 140 scientific papers including 9 monographies related to modern

conifers and radiobiological investigations of arboreal plants.

Counsel: What is your opinion on the vegetation damage in proximity to Three Mile Island?

Kozubov: The vegetation damage within the Three Mile Island accident region was caused by

the nuclear reactor accident in 1979.

Counsel: What findings from the investigation of Three Mile Island supports this claim?

Kozubov: The investigation of vegetation in the Three Mile Island region revealed growth

suppression, structural abnormalities, and patterns indicative of radiation exposure.

Counsel: What method did you use to conduct your investigation?

Kozubov: We used biological dosimetry which is the use of biological evidence of living

organisms to estimate radiation exposure.

Counsel: Why did you use this method in particular?

Kozubov: Biological dosimetry reveals the actual long-term impact of radiation exposure on

living organisms without relying entirely on instrumental data.

Counsel: Why might biological evidence be more reliable than instrument data in such cases?

Kozubov: Instruments measure radiation at a specific moment while biological samples record

the damage caused by exposure over months or years. Instruments can also

malfunction while biological samples are not dependent on human operation.

Counsel: Has there been any events in the past that notably used this method?

Kozubov: Yes, it was primarily used following the Hiroshima and Nagasaki bombings along

with the Chernobyl disaster.

Counsel: Can you briefly describe some of the varying levels of radiation?

Kozubov: Radiation is noted by the unit Gray which quantifies the energy absorbed by the plant.

Radiation from as low as 0.5 to 10 Gray can cause abnormal changes in structure and

growth patterns. Any value greater than 10 Gray can be life threatening.

Counsel: Can you further describe structural abnormalities and growth changes due to radiation?

Kozubov: High doses can stunt growth, while low doses can stimulate growth, making leaves

and their patterns larger than normal.

Counsel: Can you explain how you performed this method to estimate radiation levels?

Kozubov: The samples from 1974 to 1985 were observed through a microscope and measured

using an ocular-micrometer. Based on known radiation effects, I converted the degree

of growth into an estimated radiation dose.

Counsel: What samples were used to conduct your study?

Kozubov: We used conifer tree growth rings and plant samples collected in January 1995.

Counsel: How many samples did you obtain?

Kozubov: Two samples were collected from each of the 35 spruce and 14 pine trees.

Counsel: Can you explain what conifer trees are?

Kozubov: Conifer trees, such as pine and spruce, produce cones and have needle-like leaves.

Counsel: Why did you use conifer trees specifically for studying radiation exposure?

Kozubov: Trees have significant life spans which helps to observe an influence of unfavorable

factors over its life. They're also sensitive to environmental stress and show clear

morphological changes.

Counsel: What makes conifer trees sensitive to radiation?

Kozubov: Radiation can cause damage in proliferating cells within the tree's growth regions

resulting in tissue damage and alterations in growth patterns.

Counsel: And what are tree growth rings?

Kozubov: Tree growth rings are yearly layers of wood that record a tree's growth and

environmental conditions over time. This study is known as dendrometry and can sort

of be seen as a natural timeline.

Counsel: And what can this timeline tell you?

Kozubov: They can show exactly when stress occurred and how long it lasted.

Counsel: What characteristics do you look for in tree growth rings?

Kozubov: Wider rings indicate favorable conditions such as sufficient nutrients while narrow

rings indicate unfavorable conditions such as radiation damage.

Counsel: And what characteristics do you look for in plant samples?

Kozubov: We look for reduced or irregular growth rates, deformed needles in leaves or

branching patterns, and tissue damage.

Counsel: And what did you observe within the samples?

Kozubov: Our obtained data demonstrating the dynamics of annual wood increment illustrated

prolonged trough which indicates lasting stress. Abnormalities also increased with

radiation exposure, and the damage is visibly present showing all of the characteristics.

Counsel: What did your findings suggest about radiation levels in affected areas?

Kozubov: Trees mainly located West and North-West of the power plant showed growth

inhibition in 1979 and stimulation in 1980, indicating radiation doses of 0.5 to 2 grey.

Counsel: Can radiation effects appear immediately, or can they be delayed?

Kozubov: Both, while some structural changes at the cellular level occur quickly, the effects is

often most visible in the years immediately following the irradiation. In this case, the

1980 growth period following the 1979 Three Mile Island event.

Counsel: Based on your analysis, what conclusion can you draw about radiation exposure levels?

Kozubov: The observed plant damage suggests that radiation exposure levels were likely in the

low to moderate range, as low as 0.5 Gray, which is sufficient to cause measurable

long-term damage.

Counsel: Do you have a degree of certainty about what caused the damage of conifer organisms?

Kozubov: Yes, the damage was caused by the 1979 nuclear accident in Three Mile Island.