Police officers put soluble aluminum chloride into water, which can neutralize cadmium, a highly toxic heavy metal contaminant found in Longjiang River in Liuzhou city, South China’s Guangxi Zhuang autonomous region, Jan 29, 2012. The neutralizers have been dumped at five locations along the river since January 15, when the contamination was first detected. According to authorities monitoring the situation, cadmium level at the pollution source has reached a safe range and tap water will remain safe. [Photo/CFP]