Fig.7 presents a surface concentration risk and maximum concentration at coasts of Conakry with a north-northwest wind direction and 3.4 m/s spreading, the dominant wind direction for the proposed between Guinean dry and rainy seasons date. Also, a surface contaminant: concentration risk and maximum concentrations/spill mass fraction in percent, with wind direction southwest (SW) and3.4m/s spreading is presented in Fig.8.