Abstract:

Long used in the domain of archaeology, the C14 isotope has become an essential tracer in the evaluation of environmental fossil pollution. Since modern times, the combustion of fossil fuels such as coal, oil, natural gas, etc. in urban and/or industrialized areas releases a significant amount of fossil CO2 into the environment. Thisincrease the concentration of CO2, but also causes changes in the isotopic composition of carbon resulting in a deceased of the C14 concentration in the atmosphere and in other carbon reservoirs (terrestrial and marine biosphere).This phenomenon is the SUESS effect. The most favorable types of samples for such a study are leaves of trees or cernes. These reflect better the changes of the radiocarbon concentration in the atmosphere due to the biological assimilation of carbon from the air through photosynthesis. The evaluation of the Suess effect in polluted areas (Dakar region:UCAD Botanic Garden, Mbao Forest, SAR Factory, Beach)can be done using mass balance equations. From this model, we determined the fraction of fossil fuels .The values we found vary between 0.25% in UCAD Botanic Garden and 4.19% in Mbao Forest, and they are all positive, which effectively proves the existence of the Suess effect in our sites. 

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