Poo gurus? Researching the threats and opportunities presented by human…
Poo gurus? Researching the threats and opportunities presented by human waste (Jewitt 2011)
Huge Spatial inequalities exist in the extent to which waste threatens human, environmental and economic health, broad awareness in the UK of the need to wash hands and the environmental problems associated with sewage treatment and disposal. In Asia, 52% of people have no access to basic sanitation, 95% sewage untreated.
Facilitates the transmition of disease such as typhoid and cholera, plus significant economic impact e.g. lost of tourism revenues due to perception of poor sanitation
Human excreta could also be used as a resource to be utilised to promote environmental quality, meet human livelihood needs and generate economic benefits- humanure for agriculture- improved nutrient status and fertiliser
Geographical research on the spatial and temporal elements of human excreta focused on faecal transmission routes, cultural and historical geographies of agriculture, sanitation and cholera,
Particular attention is drawn to the (temporally fluctuating and regionally varied) tensions and ambiguities that
exist between the status of human excrement as a threat to human/ environmental health and as an important resource (in the form of ‘humanure’, ecological sanitation and ‘excrement to energy’) for human livelihoods. Examples are drawn from both the global North and South.
Dirt pollution and taboo; insights into the spatial and cultural boundaries surrounding human waste
concepts of dirt, pollution and taboo enable different cultures to construct boundaries and identify (real and symbolic) spatial limits that enable them to feel secure and in control of their environment. Geographical tensions over the private production and usually public management of excreta
The conceptualisation of dirt and cleanliness in different temporal and spatial contexts and investigate how these find expression within (and influence the arrangement of) different urban and rural spaces.
Dealing with the threat of excrement
Human disgust for excrement universal, variations in sanitation systems geographically and historically
Not until late 19th c that the linkages between bacteria and disease were fully understood, germs and pathogens equal a wide range of illnesses. quickly contaminating food and water. Cross contamination by using same sites
open defecation is the norm: a situation that facilitates the spread of disease due to poor understandings of the
health risks associated with human waste. For those lucky enough to have access to sanitation, the most widely used systems consist of either ‘flush and discharge’ or ‘drop and store’ arrangements
There is no connection between water shortages and disposal of excreta, higher pressures with an extra 2bn urban dwellers in 20 years time
Even where sewage treatment systems are widespread, human waste still represents a significant environmental threat. Primary and secondary treatment of sewage often fails to treat industrial pollutants or to prevent nitrate and phosphate rich effluent reaching water bodies and causing eutrophication. The dehydrated sludge that results from such processes contains a wide range of toxic materials including heavy metals, organochlorine oestrogen mimickers, radioactive material from hospitals, and phenols
sewage sludge has little nutrient value as most of the nitrogen is lost during sewage treatment and disposed along with the wastewater. By contrast, heavy metal concentrations are very high and sewage sludge also contains complex mixtures of chemicals which have
much greater potential to cause environmental health problems than when present in isolation. But alternative sewage treatment methods are very expensive. A 2001 estimate of the cost of achieving full compliance for sewage in the EU by 2010 was $150e215 billion, while
in the USA, pollution control between 2001 and 2021 is likely to cost $325 billion, with $200 billion for treating sanitary overflows
Less developed country governments are faced with the choice of expanding existing centralised sanitation and sewage treatment systems of seeking alternative solutions making better use of human waste and creating fewer environmental problems
Human waste as a resource: 'where there's muck there's brass'
Are local taboos surrounding excreta change a resource rather than a threat
Humanure: transforming filth into food
Sewage as agricultural fertiliser on and off in European history
England- efforts to transform 'filth into food', carting sewage from urban to rural areas to be used as an agricultural fertiliser
However competition made animal manure a more viable option
Ecological sanitation: a more rational use of human secretions?
The adoption of on-site ‘composting’ or ‘ecological sanitation’
(ecosan) systems in different geographical contexts indicates how
positive associations between sanitation and fertilizer production
or income generation can sometimes promote quite significant
changes in attitudes towards (and practices surrounding) human
excreta. In Sweden, for example, composting toilets have become
quite popular as sanitation and waste management systems in
holiday cottages, despite their users being accustomed to conventional ‘flush and discharge’ systems in their main homes
Ecosan systems being developed in the global south to provide sanitation and income generating opportunities. Environmentally or economically appropriate sanitation as it requires neither water for flushing drains nor drains for excrement removal . Remove the need for water collection associated with pour flush toilets
ecosan systems that divert urine provide an important source of free fertilizer as the 4-500 L of urine that each adult produces annually “contains enough plant nutrients to grow 250 kg of grain, enough to feed one person for one year”
the extent to which this is considered acceptable
varies greatly from place to place and between ethnic, socioeconomic and cultural groups: a situation that limits the widespread adoption of ecosan systems where preferences for ‘flush and discharge’ systems are pronounced
Excrement to energy
biogas digesters are widely used for energy production in many parts of the global South world with China having been a leader in the field since the late nineteenth century
Bio gas methane has a wide variety of uses including the provision of cooking and heating gas, electricity, vehicle fuel when processed and introduced into natural gas pipelines
When combined with China’s annual production of night soil, this ‘waste’ could theoretically generate 130 billion m3 of methane (equivalent to 93 million tonnes of coal) as well as reducing the proportion of waste going to landfill
re-integration of human waste or biogas sludge into soil systems can help to address global warming by reducing methane emissions, promoting plant growth and sequestering carbon
greenhouse gas emissions from biogas
production are lower than for many competing fuels
the biogas used to fuel vehicles produces 95% less CO2 and 80% less nitrous oxide than diesel as well as having no particulate emissions and there is enough of it available to fuel half the UK’s HGV fleet.
Nepal’s national biogas program supported the construction of 200,000 plants between 1992 and 2009 while Vietnam’s national program promoted the construction of 26,000 plants between 2003 and 2006
Despite the many inter-linkages between excreta, environmental quality and human health plus the fascinating ambiguities and variations over time and space in socio-cultural attitudes towards it, human waste rarely forms a central part of geographical analysis or academic research more generally
Wider taboos associated with human waste often render them culturally unacceptable- ecosan and anaerobic digestion
Social conceptualisations of disgust vary enormously between different places and cultures are rarely static
there is an urgent need to understand how local socio-cultural norms surrounding human excreta interact with
wider political, physical and environmental constraints if appropriate and sustainable excreta management systems are to be developed for over 2.6 billion people
translating such research into policy can be an uphill struggle given the low priority given to sanitation in much of the global South and a general lack of awareness among policy-makers about alternative sanitation systems such as ecosan.
success is often greatest where the co-benefits of such systems (waste water treatment, sanitation, energy) are clearly demonstrated to potential users, funders and policy-makers.