On the 21 to 22/01 and 24 to 25/01 nights, the air monitoring stations continuously recorded mercury (Hg) concentrations as high as 1 micro g/m³, i.e. 1,000 times greater than the WHO threshold for chronic exposure.
Laborious research involving significant human and material resources including a mobile laboratory helped identify the source of pollution: the incinerator of a metal foundry producing lead bullions from old batteries. A concentration of 9,300 mg/m³ of mercury was measured outside the incinerator’s stack that was stopped shortly after.
An enquiry was conducted. The operator was unaware of the origin of pollution since the company did not recycle mercury.
The environmental police sealed the batches of waste in question (batteries from France) to check for any possible mercury pollution. According to preliminay results, some batches contained mercury batteries. The waste was then treated using an adapted process. A specialised company carried out a land pollution survey around the plant to assess the impact of pollution on health and environment.
Besides the fact that the awareness resulting from the incident led professionals in the battery recycling sector to raise questions on securing their supplies, concrete preventive measures were taken in the company during the various stages of its processes to avoid such accidental spills from reoccurring: increasing accountability among suppliers, checking incoming material with a manual mercury detector, installing a flue gas scrubbing device using activated charcoal, checking the efficiency of gas scrubbing by constantly monitoring the mercury level in the flue, drafting procedures on taking action and informing authorities if atmospheric emission standards are crossed, etc. There measures were made part of the new operating license of the company that stipulated even more stringent emission standards. The company was to be heavily fined by the administrative authorities.