In 1986, on the border of Switzerland and Germany, 1350 tonnes of highly toxic compounds suddenly went up in flames at a warehouse belonging to Sandoz (now part of Novartis). The fire brigade responded promptly and put out the fire in about five hours. But to do so they used millions of liters of water. Due to inadequate catch basins at the factory, 20 tonnes of a pesticide-brew tagged along and flowed into the Rhine. Eventually within a couple of weeks, along a 400 km path, fish and birds were killed, and so were most of the eels in the river. The Ijssel River as far as the Netherlands was affected, even though they closed floodgates. Initially a Sandoz spokesperson had dismissed the 70-km long red slick as “a harmless dyestuff” Understandably the safety director of the company was later pelted with dead eels by protestors.
The most problematic compounds in the mixture released into the river were dinitro-orthocresol, propetamphos and parathion. Until 1991, the first compound was used as a pesticide. It’s toxic to aquatic organisms at low concentrations(0.07 to 5.7 ppm). The latter two are organophosphate pesticides, which are cholinesterase inhibitors and which are also moderately to highly toxic to fish. Parathion, specifically, is lethal after 96 hours of exposure to 50% of fish at concentrations ranging from 0.02 to 2.7 ppm, depending on the species.
As a result of the public outcry from the disaster, the Rhine Action Program came into effect in the following year. It set goals to cut 1985 discharge levels by half. It increased safety regulations for industries. Adequate catch basins had to be set up to prevent leaks into the river. Spawning grounds for salmon had to be restored in the Rhine’s tributaries with the hope of having salmon again in the river by the year 2000. Finally, shoreline ecosystems had to be revived with indigenous species. Fourteen years later, three years ahead of schedule, salmon returned to the Rhine. Nitrates and phosphate levels were cut by 50% and there was a 80 to 100% reduction in some other forms of water pollution.
A second program came into effect in 2001 when the ministers in charge of the Rhine adopted “Rhine 2020“. Here’s an outline of its main goals.
(1)The presence of salmon in the Rhine is still dependent on human intervention. One aim of the new program is to get wild salmon from the ocean to return and to increase population to self-sustaining levels.
(2) A second commendable goal is to keep improving water quality. A number of target values have been set, and currently the elements and compounds whose concentrations are still above desired levels are copper, cadmium, zinc, diurone and benzopyrene. Diurone was a mercury-based diuretic Benzopyrene is a group 1 carcinogen formed from the combustion of oil, wood and tobacco.
(3) Since lowered groundwater tables pose a problem in parts of Moselle/Saar, the Lower Rhine and the Delta Rhine, in particular in mining zones, Rhine 2020 also aims to protect drinking water in those areas.
Here in Quebec, we have something comparable to the Rhine 2020 program known as the St. Lawrence Action Plan, but unfortunately it does not include specific goals with regard to reducing contaminants. And yet the sediments of the St.Lawrence are moderately contaminated as revealed by this 2012 map:
We also have a serious problem with belugas, whose population in the gulf of the St. Lawrence River has declined from 8000 individuals in 1920 to 886 in 2012, Hunting of belugas was banned in 1979, yet the species continued to suffer. Although the concentration of many contaminants declined, there was a doubling of PBDE levels in male belugas between 1985 and the 2000s. PBDEs are polybrominated diphenyl ethers, compounds used as flame retardants in many household goods. A number of toxicological studies have demonstrated that exposure to PBDEs may have critical endocrine disrupting effects during fetal development of belugas. Biologists realize that a number of other stress factors are involved, many of which are, however, also caused by mismanagement of the river. For instance, toxins released by some algal blooms could very well be involved. There were also 334 spills involving ships in the St. Lawrence River between February 2002 and November 2012. Meanwhile Environment Canada is at least currently considering prohibition of PBDE compounds.