The Rhine is one of the world's most scenic and storied waterways. It was a commercial route before Christ, and Julius Caesar first spanned it with a bridge in 55 B.C. Along its picturesque banks, flanked by medieval castles, are Drachenfels, the cliff where Siegfried slew his dragon, and the Lorelei rock, where a beautiful siren lured rivermen to their death on the treacherous shoals.
The Rhine is also one of the world's filthiest rivers. The crystalline waters that tumble from Alps near Reichenau, Switzerland, are choked with wastes by the time they pour into the North Sea, 820 miles away. At Basel, the Rhine picks up city sewage; the chemical industries near Mannheim dump acids, oils, phenols, ammonia, dyes, chlorine, sulphate, iron, copper, bleach, cadmium and formaldehyde into its waters; the coal mines near the confluence of the Ruhr disgorge calcium deposits and sludge; the steel mills of Cologne contribute iron dross, furnace slag, oils and fats. As a result, the Rhine has come to be known as "Europe's longest sewer."
Closing the Sluices. Over the years, the pollution has taken an ecological as well as esthetic toll. The Rhine salmon, once a river staple, has long since disappeared from the murky waters, as has the sturgeon. The hardy varieties of fish that remain—bream, carp, perch and pike—cannot be sold because the river's high phenol content makes them smell and taste foul. Last week even the survivors were imperiled. Millions of dead fish floated to the surface, victims of the worst case of pollution in the river's history.
The first public warning to the Dutch came from a German police boat at the tiny border town of Lobith, where the Rhine flows from West Germany into The Netherlands. "The river is poisoned!" a German policeman shouted to a Dutch police launch. "Nobody knows what it is."
The Dutch, dependent on the Rhine for nearly half their drinking water, closed off the sluices that fed the river into purification plants. As rumors swept The Netherlands that nerve gas had contaminated the Rhine, police warned farmers to evacuate their cattle from riverside meadows. Some intrepid souls who still take dips in the rancid waters were dragged from the river. Within hours, tons of dead fish began drifting, belly up, across the border.
Delayed Warning. The Dutch were understandably furious. Five days before they were warned, dead fish, ducks and rats had been observed below the German town of Bingen. Why had the Germans failed to sound the alarm sooner? The North Rhine-Westphalian state government explained that a warning was issued to all German waterworks along the river. But then along came the weekend, and officials simply took off without passing the word.
The Germans were also slow in identifying the offending poison. Though nearly 50 German laboratories were reportedly making tests, it was the Dutch who first isolated the killer. The substance, they said, was a bug-paralyzing insecticide called endosulvan and marketed as Thiodan. A sulfurous acid ester, endosulvan is described by its manufacturers, the Hochst chemical works just west of Frankfurt, as harmless to warm-blooded animals, including humans, even though one microgram (less than one three-millionth of an ounce) in a quart of water is enough to kill coldblooded fish.