However, increased contact with radioactive substances increases the risk of future illness. A wide variety of health problems can occur from excessive exposure ranging from leukaemia and other cancers to a lowering of the immune system, anaemia and birth defects. The young and the pregnant are particularly at risk. Radiation cannot be seen or felt and can take years to exert its effect after exposure to it. In particular, radioactive substances have the potential to cause greater damage if ingested or inhaled.
Any radioactive material has the potential to contaminate the surrounding environment.
During loading, transport and storage there is well documented evidence that contamination and leakage can and has occurred. The geology of Trecwn results in extensive movement of ground water through the rock and tunnels. There are real fears that any radioactive leak will contaminate this water which feeds the water courses of the Cleddau and the Gwaun rivers. Drinking water for most of Pembrokeshire is extracted from the river Cleddau and the results of any contamination would be unthinkable. Upward seepage of radioactive gas, produced when organic matter in the waste decays, could result in soil and pasture contamination.