Hygiene versus fertiliser: the use of human excreta in agriculture--a Vietnamese example.

The use of human excreta as fertiliser in agriculture is a common practice in parts of South East Asia benefiting production but at the same time a risk factor for increased helminth infections. This paper describes the hygienic handling of human excreta for use in agriculture in Central Vietnam from a practical farming perspective presenting the farmers perceived health risks and benefits of its use. Further, in the study findings are discussed relating to the new Vietnamese guidelines for the use of human excreta in agriculture to their implications on an on-farm context. A total of 471 households in five communes responded to a structured questionnaire. This survey was supplemented by focus group discussions, key informant interviews and participant observations. More than 90% of the surveyed households used their own excreta as fertiliser and a total of 94% composted the excreta before use, either inside or outside the latrine. However, due to the prevailing design of the latrine and the three annual cropping seasons, it was found that for a minimum of one cultivation season per year 74% of the households will have only 3-4 months for composting before the input is needed in production, which is short of the 6 months stipulated in the national guidelines. The community associated great benefits from using human excreta in agriculture, especially if composted, and did not associate risks with the use of composted excreta if it was dry and lacked odour. It is recommended that the guidelines be revised and attempts made to identify ways of reducing the time needed to ensure the die-off of helminth eggs, including the use of pH regulators, such as an increased use of lime in the latrines.

Palaeoparasitology in Japan--discovery of toilet features.

The development of palaeoparasitology in Japan has occurred in recent decades. Despite the fact that archaeology in Japan has been slow to develop techniques for excavating ancient toilets, important information about the development of sanitation has been derived from the analysis of a few sites. This shows that the earliest people had very simple methods of sanitation. As populations increased, sanitation became more complex. Ditches surrounding early towns were used for excrement disposal. Eventually distinct toilets were developed followed by cesspit type toilets and flushing toilets. The parasites recovered from these toilets include many species that infect humans today. These parasite spectra reflect local use of aquatic, marine, and land animals. Fecal borne disease was an increasing problem as represented by whipworm and ascarid roundworm eggs. Interestingly, ascarid roundworms were absent in the earliest cultures and only became common with rice agriculture. Finds of pollen and seeds in toilet sediments reveal the use of medicinal plants to control the emerging problem of parasites.