Invited plenary talk given by Prof. Farid El-Daoushy at Inter. Radiation Protection Congress, Afrirpa-2010, Sept. 2010, Nairobi, Kenya. This talk summarizes the sources, processes and fate of environmental radioactivity (natural and artificial) at the earth\'s surface. It links environmental radioactivity to radiation and environmental protection issues in Africa. The role of global and regional processes on the transport and accumulation of anthropogenic waste in complex ecosystems, e.g. the Nile Basin, are described. These issues help fulfilling the African mission and vision for achieving their golals: ONE PEOPLE, ONE GOAL, ONE FAITH.

1. Sources and fate of environmental
radioactivity at the earth’s surface
Objectives: To link environmental radioactivity to
RP in Africa? To describe the benefits of Africa
from this field in terms of RP, safety and security
policies. To create a mission and a vision to fulfil
the needs of ONE PEOPLE, ONE GOAL, ONE FAITH.
Farid El-Daoushy, Department of Physics and
Astronomy, Uppsala University, Sweden

2. Sources, processes and fate of environmental radioactivity
Previous experience helps setting up an African agenda
(1) Factors influencing cosmogenic radionuclides
(2) Factors influencing artificial radionuclides:
(a) nuclear weapon-tests
(b) nuclear accidents
(c) Energy, mining and industrial waste
(3) Factors influencing the global Rn-222 and its daughters.
(4) Dynamics of cycles of natural radioactivity, e.g. Pb-210.
(5) Environmental radiotracers act as ”DIAGNOSTIC TOOLS” to
assess air and water quality and impacts of the atmospheric
and hydrospheric compartments on ecosystems.
(6) Definition of base-lines for rehabilitation and protection

3. Sources, processes and fate of environmental radioactivity
Radio-activity to trace natural and human impacts
Sources Nuclear Weapons Cosmogenic Human Biogenic Underground Volcanic
Tests Radio-isotopes Activities Activity Processes Eruption
Tracers Cs-137, Sr-90 Be-7, Be-10, Pb, Hg, soot, S-, N-, P-comp., CO2,U/Th, Ra-226, Rn- Dust, CO2
C-14, Pu-238, . C-14, I-129 CO2, CH4, NOx, CH4, .. 222, Pb-210
stratosphric-tropospheric exchange
interhemispheric mixing
atmospheric circulation
Transport precipitation
water cycle fractionation
Chemistry
assimilation
air-sea evaporation
melting exchange dispersion
ocean circulation
Ocean Deltas Lake Ground Loess
Sinks Polar Ice Corals Plants Peats Glacier
Sediments & Soils Deposits Water Deposit

4. Natural radionuclides are elegant atmospheric tracers
Rn-222 Pb-210 + 
Premordial nuclides Cosmogenic nuclides
Be-7, C-14, Be-10

Rn-222

Ra-226
 
U-238 Pb-210
What is our knowledge on such tracers in African eco-system?

5. U-238 and the global production of radon

small-scale emanation 
large-scale exhalation
Do we have an African map on the production and
atmospheric behaviour of Rn-222 and daughters

6. Artificial radionuclides from atomic bomb tests
Pu-238, Pu-239, Pu-240,
Cs-137, Sr-90,..
Knowledge on behaviour and fate of these nuclides in African
ecosystems is needed through collaborative research with
Africans. Safety and security requires preparedness.

7. Short-term transport/deposition of Chernobyl Cs-137
through tropospheric and boundary-layer processes

8. Global aerosol emissions: C, CO2, SO2, NO2, Pb
Climate influences sources/behaviour/fate of environmental
radioactivity. Impacts on life forms in Africa would be severe.
Assessing environmental radioactivity resolves these issues.

9. Global trajectories of air masses
Africa is a continent with symmetrical land around
the equator, latitudes 30⁰ south and 30⁰ north

10. Aerosol dynamics: formation, growth, attachment
(sources  transport/chemistry  deposition)
Be-7, Be-10
Rn-222, Pb-210
Understanding dry-wet removal pattern of environmental radioactivity in the atmospheric
compartment of the Nile Basin is important for both fundamental and applied research needs.

11. Large-scale and long-term transport and chemistry processes
bring soluble, particulate and collides to surface water bodies
Coupled evaporation-precipitation and surface-ground water
interaction have new climate/human impacts in the Nile Basin

12. Cloud formation Water fall Mountain lakes
Inland lakes
Agricultural/forest land
Studies of cloud, rain and surface-water processes in Europe

13. Interactions in water bodies, e.g. lakes and rivers,
depend on the involved sub-compartments

14. Natural analogues for nuclear waste studies
NORM-industries and deep geological depositories impose
new threats for coupled surface-ground water Interactions

15. Behaviour of U-series nuclides in glacial
deposits above the bedrock

16. The Nile Basin
involves complex
interactions with
several spatio-
temporal scales.
Studies of climate
and environment
impacts need
coordination of a
wide-range of
facilities/resources.

17. Studies of Complex river systems in Africa
Behaviour of radioactivity in these ecosystems
has coupled environment-climate dimensions.
Major issues to consider in these studies:
Eco-system dynamics in regional/global scales
Up-scaling from small-scale to large-scale
Threats from humans, energy and industry
Coupled effetcs from environment and climate

18. Comprehensive Test Ban Treaty ”CTBT”: global
watching gamma spectrometers
”CTBT” global watch can be
extended with African units to
build multi-tracer databases:
- to follow environmental
radioactivity in Africa
- to develop, validate and
test models in Africa
- to support climate impact
studies for sustainability of
African natural resources.

19. Conclusions
Understanding radioactivity in Africa has basic/applied input:
- Filling huge data-gaps in global environmental radioactivity
- Filling huge gaps on the behaviour of radioactivity in Africa
- Assessing climate-environment impacts in complex rivers
- Assessing global cycle of Sahara dust & impacts on climate
- Assessing climate-environment impacts on natural self-cleaning
- Understanding major impacts of climate in Africa on: sustainability of
environment and ecosystems, e.g. erosion of fertile land, salination of
freshwater, changes in evaporation-precipitation, dry-wet periods and
spatio-temporal dynamics of flooding, coupled ground-surface water
interactions, impacts of mining, industry and land-use on air and water
quality as well as quality of food-chain and biodiversity.
Thanks for your attention.