There are two mythic rivers that run through China. One, the Yellow River, takes its name from the colour it naturally takes on as it carries clay from the Szechuan highlands to the sea. The other is the Yangtze, which is not supposed to have an unusual hue—but last week it suddenly flowed through the city of Chongqing a shocking, garish orange-red, a colour you would expect to find on fingernails or a car.
Rivers have turned bright red before in fast-industrializing, pollution-plagued China. A 2008 incident on the Han River, a Yangtze tributary, was blamed on a permanganate spill; the chemical is used in tanning, metal cleaning and bleaching. Last year, an illegal recycling plant dumped red dye from plastic bags and wrappers into the Jian River. The source of the Yangtze’s new hue is not yet established. Algae can create what is known as a “red tide,” but that is a saltwater phenomenon. A deadly earthquake in the upper Yangtze valley did precede the sudden discoloration of the river. Western scientists (and conspiracy theorists) declared themselves skeptical of natural explanations for the lurid colour.
Official Chinese news sites reported that local environmental officials in Chongqing found no evidence of dangerous substances in the water. They ascribed the red colour provisionally to higher-than-normal outflows of iron-rich silt from upstream, and promised that results of their follow-up “would be announced to the public in a timely manner.” But offshore, business and local news websites hinted at a cover-up, noting that pollution is an acknowledged problem along the Yangtze, whose basin contains more than a tenth of the human race. The Yangtze River dolphin, or “baiji,” a freshwater cetacean indigenous to the river, was declared “functionally extinct” in 2006.