Retrospect on expert meeting ‘Connected Circularity’

December 19, 2022

Human excreta need to be used in a proper circular food production system. This will come along with challenges as became clear during the expert meeting of the project team ‘Ensuring Quality and Safety’ within the Wageningen University & Research investment theme of ‘Connected Circularity’.

Animal- and public health experts of RIVM, Wageningen Food Safety Research, GGD and Wageningen Bioveterinary Research were invited to come to Wageningen on 1 November to exchange thoughts about the potential risks of circular food production.

Fertilise arable land

Climate change and the growing world population put more pressure on our ecosystem. Therefore, we are forced to think about food production in a more sustainable way. For example, residuals from food production and nutrients need to be (re)used as much as possible or used differently in order to produce sustainable food. The project team ‘Ensuring Quality and Safety’ within the WUR investment theme ‘Connected Circularity’ deals with this topic. The project is especially focussed on bringing back both human and animal excreta in the food production chain, to fertilise arable land and pastures.

Potential risks

Excreta is rich in nutrients and minerals. Most of these nutrients and minerals get lost in the current food production system. Our current food production is therefore dependent on the use of artificial fertilizers. A dozen experts in the field of animal- and public health discussed the risks of such a circular system. Attention was mainly centred towards potential pathogens like viruses, bacteria, and parasites, which risks’ will possibly be different from the current system.


Pasteurisation of excreta before spreading on arable land and pastures could kill or inactivate many of these pathogens. A disadvantage of this is that many proteins denaturate if they are exposed to high temperatures. Consequently, a valuable component gets lost. On top of that, the process of pasteurisation is energy consuming, which is not desirable from a sustainability perspective.

A multi-barrier approach would be a good alternative. Action is than taken at various points in the food production chain if irregularities occur. For example, infected animals could be held separately from healthy animals or the excreta of infected animals could be kept and processed separately from that of healthy animals. However, the excreta needs to be tested then on the presence of various pathogens.

The experts agreed that there is still much work to be done before a transition from a linear towards a circular system can be made. Yet, that changes will occur is for certain.