KD-2017-017 RIVM-onderzoek ammoniak (BO-20-004-121)

A contribution was made to a Dutch article on demonstrable effects of the Dutch ammonia policy since the nineties. The RIVM acted as leading author and contains contributions from WEnR, ECN and the Lichenologisch Onderzoekbureau Nederland.

The article discusses the following aspects:

• Policy has been implemented over the past 25-30 years to reduce ammonia emissions and deposition. Both as part of the acidification policy and separately in specific ammonia emission and deposition policy. In the article, the question is answered to what extent this policy has actually worked.

• We have used as much measured data on ammonia and associated components as possible.

• The article briefly explains what can be derived / concluded on the basis of the measurements, taking into account the processes that influence the relationship between emissions and measurement.

• To this end an overview is given of ammonia-related processes in the atmosphere and (terrestrial) ecosystems. Discussed: emissions, concentrations, conversions, particulate matter, deposition, upper groundwater nature area, biomonitoring such as lichens.

The results show that:

• For all measurements of ammonia and ammonium, they have fallen in the 1990s. For a number, the decline continues (rainwater, aerosol).

• For some, the decline does not continue and little change or even an increase is observed. The increase for a number of components mainly occurs after approx. 2004-2005 (ammonia in air, throughfall).