Shell\'s managing director in Nigeria on Monday pledged the oil giant would take \"seriously\" a UN study on unprecedented pollution, but reiterated that the company was not to blame for most spills. \"It\'s important for me to emphasise that we are taking the UNEP report very seriously,\" Mutiu Sunmonu told AFP in an interview after the UN Environment Programme released the report last week. \"We are looking at it in greater detail. We are taking a comb through the report to see exactly what necessary follow-up actions will be required of SPDC.\" SPDC is Shell\'s Nigerian joint venture, the Shell Petroleum Development Company. The landmark report set out scientific evidence for the first time of devastating pollution in Ogoniland, part of the country\'s main oil-producing Niger Delta region where Shell and the state petroleum company have operated. It said the pollution may require the world\'s biggest ever clean-up, while detailing urgent health risks, especially badly contaminated drinking water. Shell faced criticism from UNEP, which said \"control and maintenance of oil field infrastructure in Ogoniland has been and remains inadequate: the Shell Petroleum Development Company\'s own procedures have not been applied, creating public health and safety issues.\" The company has long blamed most of the environmental damage in the Niger Delta on oil theft, illegal refining and other criminal activities, an assertion that activists strongly dispute. Over 70 percent of the spills in the delta is caused by sabotage,\" Sunmonu said. \"But even the remaining 30 percent is still of great concern to me because every oil we spill is bad. It\'s bad for the people, it\'s bad for the environment and it\'s also bad for the business.\" He said \"my focus on the UNEP report is to work with all stakeholders to make sure we can restore the environment in Ogoniland to its natural state as quickly as possible.\" Anglo-Dutch Shell was forced to pull out of Ogoniland amid unrest in 1993, though pipelines for its Nigerian joint venture, which includes the state oil company, and other facilities remain there. \"All the assets we had in Ogoniland have been either vandalised or really at the mercy of saboteurs,\" said Sunmonu. \"The only two assets that are active in Ogoniland are our two pipelines, and I am very confident about the integrity of those two pipelines.\"