Human excreta may be attractive as fertilizer because of the high demand for fertilizer and the relative availability of the material to create night soil. In areas where native soil is of poor quality, the local population may weigh the risk of using night soil.
The use of unprocessed human feces as fertilizer is a risky practice as it may contain disease-causing pathogens. Nevertheless, in some developing nations it is still widespread. Common parasitic worm infections, such as ascariasis, in these countries are linked to night soil use in agriculture, because the helminth eggs are in feces and can thus be transmitted from one infected person to another person (fecal-oral transmission of disease).
These risks are reduced by proper fecal sludge management, e.g. via composting. The safe reduction of human excreta into compost is possible. Some municipalities create compost from the sewage sludge, but then recommend that it only be used on flower beds, not vegetable gardens. Some claims have been made that this is dangerous or inappropriate without the expensive removal of heavy metals.