The year of freshwater – but are water regulations out-dated?

The Year of Freshwater will be a reminder to delegates at the World Summit (see related story) that the world has agreed to halve the proportion of people without access to safe water and basic sanitation by 2015.

In Europe, the European Commission has adopted a new directive to reduce freshwater pollution that will come into force in the summer of 2004. The directive bans the use of a chromate-based azo-dye used to colour textiles, following studies showing the dye is toxic to fish and other aquatic organisms and cannot be prevented from being released into wastewater during the colouring process.

But while EU directives such as the Water Framework Directive take effect to protect Europe’s waters, with many warning that the WFD is not stringent enough (see related story), some scientists are concerned that regulations on metal pollutants in water are excessive, resulting in unnecessary measures to curb pollution.

At a European Science Foundation conference on natural waters, scientists voiced their concerns that regulators are using out-dated methods of measuring the metal content and toxicity of water. Freshwater scientists have known for two decades that metal toxicity is related to particular forms of metal. For example chromium (III) is harmless while chromium (IV) is toxic. But regulators may set limits based on total chromium content rather the concentration of toxic chromium.

“The regulations in Europe are based on total metal content and are showing very little sign of changing to incorporate the science we know,” Professor Bill Davison, a freshwater scientist at Lancaster University told edie. “They’re overprescriptive and cost society at large a great deal of money. We’re restricting metals more than we need to because of poor measurement systems.”

Research scientists estimate toxicity based on metal speciation – the ‘species’ or forms of metal known to be toxic e.g. methylmercury, inorganic selenium – and are calling for regulators to start doing the same. Growing awareness in North America is leading to dialogue between scientists and the government, but the pace is slow. Australia is making the best progress, being the first country to have revised its legislation to include speciation. When water samples are found to be over the total metal limit, regulators have the option of using specialist techniques to assess whether this actually poses a threat.

Part of the problem is the lack of cheap and user-friendly methods of measuring metal speciation. But scientists like Davison are on the case. Davison’s invention, an ion-exchange tool based on hydrogels used in medicinal dosing, is being tested in Australia as an alternative method of measuring metals in rivers and streams.