Release of zinc from facilities
Zinc exemplifies the pollutants released into the water by industrial operations. The indicated amount comprises zinc and zinc compounds that are released directly into bodies of water, not into waste water. Zinc is used primarily as an alloying component and for coatings. The main sources of the zinc that is released into bodies of water are metal-processing operations, loss of zinc from galvanised pipes and quantities remaining in waste water after treatment. This data is based on the SwissPRTR (Swiss Pollutant Release and Transfer Register).
In 2020, approximately 1800 kg of zinc were released into water. The value is thus below the fluctuation range of the last 10 years and is based on the marked decrease in individual facilities. Fluctuations may be due, among other things, to uncertainties in data collection based on sample measurements.
At first glance, a reduction in the release of pollutants would seem to be a positive development for the environment, an increase negative. However, as a rule, it is not possible to judge the situation without knowing the reasons for the change and the consequences of it. It is particularly important to clarify whether a reduction is due to production being transferred abroad. If that is the case the pollutants are merely released abroad instead of in Switzerland. Switching to a different production method may bring about a decrease in levels of pollutants released, but cause an increase in other pollutants. The same considerations apply to volumes of pollutants in waste water. Furthermore, depending on the pollutant, treating the substance in waste water may be a preferable option to uncontrolled release to the atmosphere. For these reasons, the status and trend have not been evaluated.
Data on the release of pollutants and transfers of wastes are compiled in comparable ways in all countries where the PRTR Protocol has been implemented, and this includes all EU countries. However, since the figures are in absolute terms, a meaningful comparison cannot be made at the national level, because such a comparison would automatically favour smaller countries with less industry. Detailed data on individual facilities can be compared, however.
The Swiss Pollutant Release and Transfer Register (SwissPRTR) provides information about releases of pollutants and transfers of wastes. Facilities in certain industries and of a minimum size are required to report the quantities of 86 specific pollutants that were released into the air, water or ground by their operations in the previous calendar year. Threshold values specific to the different substances apply, which when exceeded trigger the reporting requirement. The data do not show directly how large the facilities in question are. Important parameters such as the production volume, number of workers or capacity of a facility influence the amounts of pollutants and waste produced directly or indirectly, and naturally vary greatly depending on the branch of industry. Industries’ self-reporting is based on measurements, calculations and estimates and is monitored by cantonal authorities.