Physiological Nitrogen release from human population
Human population living in rural areas with no sanitation might be considered as N pollution source not only due to its Nfootprint, but also via direct physiological N release. We found that in the region of Prut and Dniester catchment in 2015 N consumption was equal to N release from humans. N release varied from 4.3 to 6.8 kgN cap-1 yr-1 being substantially larger that the WMO-recommended N protein consumption (2.9-3.5 kgN cap -1 yr-1 ). Estimated N load from this source to the environment made 33 GgN yr-1 .
Per capita N footprint in various regions differs and strongly related to protein consumption rates and food production N losses (Galloway et al., 2014). It is essential that in regions with sanitation facilities physiological N excretion from humans is not considered as potential N loss pathway to the environment. This study aims: i) to compute mean food N consumption/ physiological N release from population, ii) to estimate potential contribution of human N release as N source in rural areas lacking sewage system.