GRUINARD ISLAND

Anna-Lisa Duncombe and Howard Lomax

Gruinard Island

• A small Scottish island located off the northwest coast of Scotland in Gruinard Bay.

• 1.5 square miles

• 2 miles from the mainland.

Geographic Features

• The island is mostly Torridonian sandstone overlaid by 0.3 to 0.5 meters of blanket peat bog.

• The vegetation of the island includes heather,

moss, and some braken.

Gruinard Island’s History

1942 • It was the site of a biological warfare test.• Used by the British government to investigate the

feasibility of an attack using anthrax against a German attack,

• At this time many tests were carried out

The Anthrax Tests on the Island

• On July 15, 1942 eighty sheep were taken to the island

• A bomb filled with anthrax slurry was dropped and exploded four feet above the ground.

• Sheep started to die on the third day. • The carcasses were then thrown over a cliff onto

rocks just above the waterline. Peat-filled sandbags held the bodies in place while a dynamite charge buried the bodies 10m underground.

• On September 26, 1942 a thirty-pound bomb was detonated and exploded in soft peat, contaminating the ground but no animals.

How does Anthrax Contaminate Soil?

• The anthrax bacteria lives as spores in the soil. • If an animal carcass is opened and the organisms

are exposed to air, they will form spores. • Anthrax spores are very robust• The anthrax spore may live indefinitely in the soil.• The anthrax spores themselves do not kill people. • They find their way into a person's lungs or

gastrointestinal system or skin and germinate there and produce toxins that do the dirty work.

• However, in the test on 26th September the Anthrax spores were fired directly into the peat soil.

Decontamination of “Anthrax Island”

1943:• Very little was known about decontamination

techniques. • The solution was to burn off all the surface

vegetation on the Island• However, the anthrax still survived in the soil.

1978-1986: Several ideas for decontaminationwere suggested: • Encasing the island in cement • Stripping the topsoil off the island and dumping it

into the Atlantic Ocean • Using steam, chemicals, or radiation to neutralize

the anthrax spores • Using the island as a nuclear waste facility!!!

Decontamination of “Anthrax Island”

1986 - The Final Decontamination of Gruinard Island

• After intensive soil sampling, found that the contaminated area to cover a mere 3.7 hectares.

• Irrigation lines were used to seep a 5% solution of formaldehyde into the contaminated soil,

• Formaldehyde is used as a disinfectant and kills all bacteria

• 50 litres of solution per square meter of soil. • The detonation point and the site of the

Wellington bomber's disastrous run were injected with formalin, a solution that is 37-38% formaldehyde.

However, • further sampling showed that a dangerous

amount of anthrax spores still inhabited several isolated pockets.

The treatment of these areas had to be redone, • formalin was injected to penetrate to the bedrock.• This was a complete success.

Ways of Killing Anthrax Bacteria in soil

• Concentrated doses of strong disinfectants like bleach or formaldehyde.

• Gamma Radiation

However, • They are toxic to people and the

environment• And extremely expensive

Bacteriophage Methods

• Infect bacteria in order to reproduce inside. Once they do, they use lysin to break apart their host's cell walls so the new ‘phages’ can infect other bacteria. "They cause the [bacterium] to explode,“

• A study carried out at Porton Down Defence Science Laboratory spread a harmless bacteria similar to anthrax over a soil.

• The Soil was then infected with bacteriophage virus

• Led to marked reduction in number of bacteria in soil.

Conclusion

• By the end of 1987, anthrax levels were considered to be within "safe limits"

• Sheep were allowed to roam the island once more.

• Formaldehyde could be used in this case without much effect on the mainland

• New developments in Anthrax Decontamination such as Bacteriophage may be preferable to reduce the environmental impact

• However, at the time these methods were not in widespread use.

Thank You For Listening

Any Questions?