The Dutch foundation ToxiWatch, commissioned by an association of Zubieta neighbours to monitor the contamination of the incinerator of Gipuzkoa, has shown in a new investigation that the authorities have little control over the slag or slag and ash left in the incinerators once the waste has been burned. They are investigating the case of the Dutch incinerators and the result has been disseminated by Zero Waste Europe, the largest organisation in Europe.

Apart from the very toxic ashes and particles trapped in the chimney filters, which require special treatment, the ovens of the incinerators generate on the one hand the slag or slag and on the other the ashes that the authorities consider ‘recyclable’ and that the industry presents as very suitable for soils, building materials and road fillings and even as ‘components of the circular economy’.

Approximately 20% of the mass of waste introduced into the furnaces is left in slag or slices. Of the 13 incineration plants currently in operation in the Netherlands, two million tonnes of slag are calculated which, after being stored, must be transferred to a treatment plant. In 2012, the employers of the incinerators and the Dutch Government agreed to use these resources within the framework of the country’s Green Pact. The first problem, says ToxiWatch, is that the amount of dioxins from escorts and other toxins does not appear at any time and that the standards used for quality control of these materials have been outdated by the new information that has been generated over these years. For example, recently the Basel Treaty, which monitors the standards of dioxins and other similar pollutants, has demanded that the maximum level of POP persistent organic pollutants be reduced from 15 to 1. The spread of slag poisons in nature brings the risk to humans, as a result of the consumption of plants, animals and derivatives (eggs, milk...) that live and feed on poisoned land.

Contaminants accumulate in the food chain, which explains why they exceed the standards in eggs in which dioxins spread by scurvy may appear. The aquatic fish from ports and swamps that transport escorts also show the finding of typical malformations of these POP pollutants in meats and fish eels. The Dutch government's health inspection has already warned that such problems of contamination and food fraud are occurring, which require the authorities to change the standards of these toxic materials.

However, this demand clashes with the economy, as analyzing the escorts before using them in public works would be economically unsustainable for companies. “In the end,” says ToxiWatch, thousands of tons of escorts are being used in public works, in pipelines for soils and dam waters, but there is no data on their number or on the location of these materials.”

The ashes and remains of the chimney filters form another polluting solid residue from the incinerators: 10% of the total mass of waste deposited in the kilns remains in the kilns. ToxiWatch has not even found an analysis of its toxicity. However, it is known that these hazardous wastes are either used for cement manufacturing in cement factories or deposited in deep underground deposits. As a result of the ban on landfill in the Netherlands, a German empty salt mine offers a store for them and the industry finally gets permission to move them from Holland to Germany, as the Amsterdam Government initially saw no clear export of polluting substances.

In the conclusions section of the study, ToxiWatch has asked the authorities to suspend the use of slag and ash from incinerators until its toxicity is analysed and demonstrated to be risk-free: “Continuing to use them in this way puts our health and the environment at risk.”