JEDDAH: The Health Directorate and Jeddah Mayoralty have issued a warning to residents to clean their water tanks regularly because of the danger of contracting life-threatening diseases. The health authorities stressed that contaminated water can lead to residents contracting Hepatitis A, typhoid and parasitic diseases. The World Health Organization (WHO) has stated that 40 diseases are linked to contaminated water. Dr. Sami Badawood, Director of Heath Affairs in Jeddah, said it was important to clean and disinfect water tanks yearly. The tanks should also be cleaned immediately after floods and heavy downpours. Dr. Ahmad Nabeel Abu Khatwa, an advisor at the mayoralty, said tanks should be emptied and then cleaned of all sand, dust and moss. They should then be thoroughly examined for cracks. He emphasized the importance of spraying chloride solutions inside a tank to disinfect it. The chemicals should be washed out of the tank and its walls should be washed thoroughly. He said this procedure should be repeated several times before the tank is filled with clean water. Once the tank is checked for cracks, it should be closed tightly to prevent any leakage into the tank. The Health Directorate and Mayoralty have distributed thousands of bulletins to inform the public on how to clean and disinfect tanks properly. Information is also provided on how to combat mosquitoes which transmit dengue fever.