Radioactive Substances

Radioactive pollution is the result of released radionuclides in the environment. A radionuclide is an atom with an unstable nucleus which has excessive energy. While breaking down through radioactive decay it emits gamma rays (http://en.wikipedia.org/wiki/Radionuclide).

According to the UN Atlas of the Oceans, the main sources of radionuclides released into the marine environment include nuclear weapon testing’s, fallout from accidents such as the Chernobyl accident in 1986, foundering of nuclear submarines, dumping of nuclear waste into the deep ocean, and discharges from nuclear power plants and nuclear reprocessing plants (http://www.oceansatlas.org/servlet/CDSServlet?status=ND0xOTE4MiY2PWVuJjMzPSomMzc9a29z).

Other sources are oil extraction, phosphate rock processing and radioactive transport at sea (Greeenpeace 1998). Ocean currents can transport radionuclides over large distances. Radioactive waste can be in gas, liquid or solid form and may remain radioactive from a few hours to hundreds of thousands of years (http://www.epa.gov/radiation/docs/radwaste/index.html).

Effects

Radioactive contamination can enter the human body through ingestion, inhalation, absorption, or injection (http://en.wikipedia.org/wiki/Radioactive_contamination). Long term exposure to radiation, at doses less than that which produces serious radiation sickness, may harm the DNA causing cancer or birth defects. Higher levels of exposure may lead to radiation sickness with symptoms depending on the exposure levels ranging from decreased blood cells to nearly immediate death (http://en.wikipedia.org/wiki/Radiation_poisoning).

Marine organisms may also be affected and the reproductive stages and growing tissues are the most sensitive in marine fish. Mammals appear to be the most sensitive of al fauna followed by birds and then insects (http://www.ukmarinesac.org.uk/activities/water-quality/wq8_49.htm#a5).

Global versus Caribbean Studies on Radioactive Substances

The effects of man-made radionuclides discharged into the sea still loom large in the minds of the

general public and politicians. Although threats from accidental releases cannot be ruled out, radionuclides now probably worry scientists less than any other category of marine pollutants (GESAMP 2001).

Radioactive isotopes of at least 16 of the 91 naturally occurring chemical elements are present in the oceans and there are possibly traces of a further 16 (GESAMP 1990). According to Greenpeace (1998), weapon testing is the largest single source of artificial radionuclides to the oceans through fallout. Fuel reprocessing plants are also main contributors (UNEP/GPA 2006). The weapon testing is a source of global impacts and the fuel reprocessing plants have local impact (UNEP/GPA 2006). Between 1954 and 1962, about 400 devices have exploded and each nuclear explosion released over 400 radioactive isotopes into the biosphere. Forty (40) of the isotopes are considered particularly hazardous (Greenpeace 1998). Low level concentrations are measurable in the oceans worldwide (GESAMP 1990).

According to UNEP/GPA 2006, 85 PBq (symbol for the petabecquerel, an SI unit of radioactivity equal to 1015 becquerels) of radioactive waste has intentionally been dumped into the oceans at over 80 locations worldwide. Marine accidents, losses and deliberate dumping now mean that some 50 warheads, 23 reactors and an unknown number of other devices rest on the sea bed (Broadus & Vartanov 1994). This also includes power units from satellites which have re-entered the Earth's atmosphere.

Belgium, France, Germany, Italy, Japan, Netherlands, New Zealand, Republic of Korea, Sweden, Switzerland, the former Soviet Union, the United Kingdom and the United States maintained sea disposal as a waste management option between 1946 and 1991 (UNEP/GPA 2006). Most of the dumping occurred in the North-East Atlantic and in total about 46 PBq of low-level nuclear waste was dumped at sea during this period (UNEP/GPA 2006).  According to Greenpeace (1998) illegal dumping operations took place over a period of 30 years in the Barents and Kara Sea (part of the Arctic Ocean). There is evidence that some low-level waste have been leaking but dumped reactors do not seem to have leaked so far according to the same study  by Greenpeace. .

The most significant authorized releases of radionuclides to the sea are from nuclear fuel-cycle installations, particularly spent fuel reprocessing plants located at Sellafield (UK), La Hague and Marcoule – now closed – (France), Trombay (India), and Toki-Mura (Japan) (UNEP/GPE 2006). So long as they are well operated and regulated (not always the case) their routine emissions are thought to present relatively minor risks to human health on a regional or global scale (GESAMP 2001).

Atmospheric deposition (fallout) is still a significant pathway on land and at sea. However, it is becoming less important as the atmospheric reservoir of fission products from weapons testing is reduced by radioactive decay. Fallout from the Chernobyl accident is also gradually diminishing in all areas except those where terrestrial runoff is still adding new radioactive materials (GESAMP 2001). Overall, levels of radioactive pollution are low and increasing concern and regulations are helping to reduce these (http://www.oceansatlas.org/servlet/CDSServlet?status=ND0xOTE4MiY2PWVuJjMzPSomMzc9a29z).

Almost every country in the Wider Caribbean Region have been targeted as a nuclear waste dumpsite by waste brokers operating from developing countries and this was expected to increase (UNEP/CEP 1991). However, while most countries have banned this kind of import, some still remain vulnerable.

A serious potential risk both for people and the environment of the region is the transport of radioactive material by ship in the Caribbean Sea and Panama Canal (UNEP/CEP 1991). In year 2006 Panamanian citizens voted and approved the expansion of the Panama Canal and on September 3 in 2007 the project officially started. The project will double the canal's capacity and allow more traffic. More, and bigger ships crossing the Caribbean Sea, arguably increase prospects for some type of accident to occur (http://www.coha.org/).

According to the Counsil on Hemispheric Affairs (2008) the Surinamese government has made the decision to build a facility that would serve as a nuclear-powered aluminum smelter. Concerns over possible environmental risk for the region are according to the Surinamese government dealt with and suppliers will collect the waste every three years.  During the collection there will be an advanced monitoring system in place to track delivery of the fuel and collection of the waste (http://www.caribbeannetnews.com/news-505--36-36--.html). However, the risk factor will most likely increase if more fuel and wastes are handled.

On December 20, 2006, the United Nations General Assembly adopted a resolution entitled: "Towards the Sustainable Development of the Caribbean Sea for present and future generations". The resolution is an effort to secure the recognition of the Caribbean Sea as a special area in the context of sustainable development by the international community. Through the adoption of this resolution the community of Greater Caribbean nations has advanced toward the fundamental objective of having the Caribbean Sea declared a special zone (http://www.caribbeannetnews.com/cgi-script/csArticles/articles/000052/005290.htm). By being classified as a special area the Caribbean Sea would be provided with a higher level of protection than other areas of the sea. Specific measures can then be used to control the maritime activities, such as ship routing measures, strict application of MARPOL discharge and equipment requirements for ships, such as oil tankers; and installation of Vessel Traffic Services (VTS) (http://www.imo.org/Environment/mainframe.asp?topic_id=1357).

Laws, Regulations, and Policy Responses on Radioactive Substances

The most important regional legal framework in the Wider Caribbean Region for the protection of the Caribbean Sea from pollution is the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region (Cartagena Convention). The Convention entered into force in 1986 and is a legally binding, regional multilateral environmental agreement for the protection and development of the Wider Caribbean Region. The Cartagena Convention deals with radioactive substances through the Protocol Concerning Pollution from Land-Based Sources and Activities (LBS Protocol) and by its focus on preventing air pollution.

The LBS Protocol sets forward general obligations and a legal framework for regional co-operation, provides a list of priority source categories, activities and associated pollutants of concern and promotes the establishment of pollution standards and schedules for implementation. Radioactive substances are primary pollutants of concern listed in Annex I. Consequently, radioactivity is a characteristic to be considered while evaluating the pollutants of concern listed in Annex 1, and other pollutants causing concern for the countries.

Another relevant regional framework is the Treaty for the Prohibition of Nuclear Weapons in Latin America and the Caribbean  (Tlatelolco Treaty). This Treaty aims to ensure absence of nuclear weapons, complete disarmament, use nuclear materials/facilities only for peaceful purposes, to prohibit and impede the testing etc. All 33 States in the Latin America and Caribbean Region have signed, ratified and have waived Article 28 of this Treaty, which entered into force in April 1969. Read more at http://www.opanal.org.

Some of the International Conventions on radioactive substances include:

  • The Convention on the Prevention of Marine Pollution by Dumping of Wastes and other Matter (London Convention). Prevents the dumping of wastes, including radioactive waste at sea. Entered into force 30 august 1975. Read more at http://www.imo.org.
  • The Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management. Promotes safe and environmentally sound management of spent fuel and radioactive waste covering issues such as storage, transboundary movement, treatment and disposal of these materials. Entered into force 18 June 2001. The USA is the only country in the Wider Caribbean Region that has signed this convention. Read more at http://www.iaea.org.
  • International Convention for the Safety of Life at Sea (SOLAS), with the chapter on Nuclear ships. Gives basic requirements for nuclear-powered ships and is particularly concerned with radiation hazards. Read more at http://www.imo.org.

What is the Caribbean Environment Programme (CEP) doing?

  • In 1991 a technical report was prepared by CEP concerning The Transboundary Movement of Hazardous and Nuclear Wastes in the Wider Caribbean Region (CEP Technical Report No. 7 1991). This report covers issues like the source and scope of the waste trade problems in the Wider Caribbean region, and radioactive waste within the region.
  • CEP supports the Association of Caribbean States (ACS) Caribbean Sea Commision and is one of the regional technical advisory agencies on the committee. The Caribbean Sea Commission promotes preservation and sustainable use of the Caribbean Sea. One of its major tasks is to develop a plan of action and programme of activities which will reinforce the Association’s ongoing initiative to have the international community declare the Caribbean Sea a Special Area in the Context of Sustainable Development.
  • CEP has signed a MOU with the international Atomic Energy Agency (IAEA) to collaborate on the peaceful use/application of analytical techniques using radionucleotides and isotopes. Specific examples are in isotopic hydrology and assessing historical trends in pollution hot spots within the region.

References

CEP was established in 1981 as part of the Regional Seas Programme in recognition of the importance and value of the Wider Caribbean Region’s fragile and vulnerable coastal and marine ecosystems including endemic plants and animals.

© United Nations Environment Programme