Located 1 mile off Gruinard Bay, between Gairloch and Ullapool on northwestern coast of Scotland, Gruinard Island was the site of the first biological warfare test by British military scientists from Porton Down in 1942. Eighty sheep were taken to the island and bombs filled with anthrax spores were exploded close to where selected groups were tethered. The sheep either died during the test or were killed afterwards, as a precautionary measure.
For many years it was judged too hazardous for the public to access the island. In 1981, a group of activists known as Dark Harvest, an affiliate of the Scottish National Liberation Army, left a sealed package of a soil sample from the island outside the military research facility at Porton Down; tests revealed that it contained anthrax bacilli. Dark Harvest wanted to draw attention to the contamination of the island and the failure of the authorities to deal with the situation. A few days later, another sealed package of the soil was left in Blackpool, where the ruling Conservative Party was holding its annual conference. Starting in 1986, a determined effort was made by the authorities to decontaminate the island, with 280 tonnes of formaldehyde solution diluted in seawater sprayed over all 196 hectares of the island and the worst-contaminated topsoil around the dispersal site removed. On 24 April 1990, following 48 years of quarantine and four years after application of the formaldehyde solution, the island was declared safe for the public. Today the island remains uninhabited.