Presentation on theme: "G RUINARD I SLAND D ECONTAMINATION By Jhen Pei Seah Xiqing Wang."— Presentation transcript:
G RUINARD I SLAND D ECONTAMINATION By Jhen Pei Seah Xiqing Wang
G RUINARD I SLAND, S COTLAND Gruinard Island, in Western Scotland, is just about 1.5km off the mainland, in Gruinard Bay, half way between Ullapool and Gairloch in the Highlands.
G RUINARD I SLAND BEFORE 1942 The Norse name roughly translates as “the island in the green.” The island served for years as a summer pasture for sheep, a spot to hunt rabbits and a favourite local picnic ground.
T HE C ONTAMINATION 1942 - 1943 British scientists used Gruinard Island to carry out biological warfare experiments with anthrax spores. It was recognised that tests would cause long- lasting and widespread contamination. In order to limit contamination, a remote island was required. Thus, Gruinard was purchased from its owner.
T HE C ONTAMINATION 1942 – 1943 (C ONT ’ D ) Initial symptoms after inhalation might include mild fever, malaise, fatigue, coughing and, occasionally a feeling of pressure on the chest. Occupational exposure to infected animals or their products (such as skin, wool, and meat) is the usual pathway of exposure for humans. mediastinal widening
T HE C ONTAMINATION 1942 – 1943 (C ONT ’ D ) First experiment on 1942, a bomb containing billions of anthrax spores was exploded, and it killed 60 sheep that were brought to the island. Similar occasional tests were also carried out throughout the World War II. In 1943, dead sheep from Gruinard washed ashore on the mainland, contaminating several farm animals.
I NITIAL D ECONTAMINATION 1948 - 1968 Scientists visited Gruinard Island annually and found out that the island remained contaminated, but no precise counts of the actual contamination were available. Thus, efforts were only at the ‘testing’ stage instead of real decontamination projects.
T HE S URVEY The island was marked onto a grid system and soil samples were taken at regular intervals. After testing them in the laboratory for anthrax spores, a detailed map of affected area was produced. Several solutions to decontaminate the island were suggested, for example: - Concreting the entire island - Designating it a nuclear waste storage area - Bombarding the spores with gamma radiation - Moving the contaminated top soil into the North Atlantic - Soaking the island in potassium permanganate solution - Raising the temperature of the island to about 1000 0 C for two minutes.
O PERATION D ARK H ARVEST 1981 In 1981, Dark Harvest took samples of the contaminated soil from Gruinard and left one package of it at Porton Down; while another in Blackpool, where the ruling Conservative Party was holding its annual conference. Under public pressure, the government responded by authorising the most extensive survey of Gruinard ever taken.
T HE F INAL S OLUTION 1986 - 1987 280 tonnes of formaldehye solution diluted in seawater being sprayed over the entire island. The worst contaminated topsoil was removed. A flock of sheep was then placed on the island and remained healthy. In mid-April of 1990, the Ministry of Defence declared Gruinard Island ‘safe’, ending its 48 years of quarantine.
T ODAY Prior to the emergency in the US in October 2001 the island of Gruinard was the main example of successful decontamination of an area contaminated with anthrax spores. However, in 2004, a quicker, cheaper and more effective way of decontaminating soil infected with anthrax has been discovered. Scientist suggested to use a virus named Bacteriophage, which consume and kill bacteria.