A comprehensive environmental assessment of oil-impacted sites in the Ogoni region of Nigeria's Niger Delta is to be launched by the United Nations Environment Programme....Achim Steiner, UN Under-Secretary General and UNEP Executive Director, said:.."We will be deploying several teams of international and local experts...to conduct...assessments in over 300 sites to identify the impacts of oil on environmental systems...as well as the direct and indirect effects on biodiversity and human health," he added. [refers to Shell]