Prince Sattam bin Abdulaziz, Governor of Riyadh Region and Chairman of Supreme Committee for Environment Protection, chaired here Sunday evening, the 9th meeting of the Higher Committee in the presence of Prince Mohammed bin Saad bin Abdulaziz, Vice Governor of Riyadh Region and Deputy Chairman of the Committee. A Member of Higher Commission for Riyadh Development and Chairman of Projects and Planning Center of the Commission, Eng. Ibrahim bin Mohammed Al-Sultan pointed out that the meeting was briefed on the final report of the committee in-charge of defining anti-environment activities and facilities, south of Riyadh city, numbering 587 plants and facilities, and decided to close and remove all unlicensed activities in areas not dedicated to these activities. He noted that the meeting reviewed the causes of high rate of air pollution with suspended particles in the city of Riyadh, indicating that technical studies have shown that natural factors, particularly dust storms, accounted for 96%, while human activities including factories, power plants and construction projects accounted for 4%.