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Background

Health and Hygiene Issues

Health Risk Management

Compiled by:: Gina S. Itchon (Xavier University), Robert Gensch (Xavier University)
Adapted from:: STENSTROEM, A.; SEIDU, R.; EKANE, M.; ZURBRUEGG, C. (2011)

Executive Summary

Sanitation systems should serve as a barrier or a series of barriers against different types of waterborne and excreta related pathogens in order to reduce the associated health risk to an acceptable minimum. It is recognised that a sanitation system including the treatment, safe disposal and reuse of human excreta and wastewater should not be based on a single barrier (such as treatment alone) but that a multi-barrier approach is required to effectively eliminate and/or inactivate the various types of hazardous microorganisms present in excreta. Achieving the objective of the multi-barrier approach requires a paradigm shift from the assessment of sanitation technologies as mere technological units to one that encapsulates the health risk and mitigation, institutional, socio-cultural, environmental and financial dimensions of sanitation technologies (adapted from STENSTROEM et al. 2010).

Multi-Barrier Approach

A barrier is a part of the treatment or handling chain of a sanitation system that substantially reduces the number of pathogens present in excreta. The barrier function is normally expressed in log-terms, where one log is similar to a 90% reduction, two logs similar to 99% reduction and so on. In the technical barriers, the reduction can be simplified to occur through different treatment processes. There is an additional risk of disease transmission related to the usage of sanitation system as well as the handling or use of the end products. These relate to environmental persistence and die-off, dilution factors, exposure and the dose that humans are exposed to (see also waterborne diseases pathogens and contaminants).

Barriers to protect oneself from infection are needed at all different points of exposure and for different exposure groups, i.e., those using the system, those handling the end products or those consuming crops fertilised with them.

A system for the safe disposal and reuse of human excreta and wastewater should not be based on a single barrier such as treatment, but that a multi-barrier approach is required to effectively eliminate and/or inactivate the different hazardous microorganisms spread through various routes as shown in the figure below (CARR 2001) and to obtain a high level of reliability. Achieving the objective of the multi-barrier approach requires a paradigm shift from the assessment of sanitation technologies as technological units, to one that encapsulates the system itself and human behaviour.

Transmission Routes of Excreta-Related Diseases

The transmission routes of excreta related disease, exposure points and the health risk factors involved are directly interlinked. The transmission of excreta related pathogens may be either primary (direct exposure) and/or secondary, (exposure through an external route). Primary transmission includes person to person contact, including short distance airborne transmission. Secondary transmission includes vehicle-borne (food, water etc.), vector borne and airborne long-distance transmission.

The spread of pathogens from excreta of an infected individual to a healthy individual – The faecal oral pathogen transmission routes. Source: CARR (2001)

Critical Questions to Identify Severity of Health Risks

Closely related to the various transmission pathways are the following critical questions that need to be addressed in identifying the severity of the health risk associated with a particular pathway:

WHO is exposed? This defines the groups that potentially are at risk.
HOW MANY people (individuals) are likely to be exposed directly or indirectly? This may include the individual users, but as well maintenance workers or the number of people that are consuming crops fertilised with treated excreta, or the people indirectly exposed due to contamination soil, surface/groundwater or from contaminated drinking water sources.
WHERE does the exposure occur within the sanitation system? With this question, one follows the system from the user to the potential step of reuse or disposal and also account for secondary exposure that occurs due to environmental pollution.
WHICH routes should we consider? Is it mainly due to direct contact? Is it due to contamination of crops, soil or water sources? Is it due to mosquito breeding and so on?
HOW frequently does exposure occur? Is this every time, daily, weekly or perhaps just once a year? Even if exact figures cannot be obtained, it may be of value to at least have a “guesstimate” about the frequency of exposure.
WHAT dose of exposure occurs? This is also difficult to estimate, since it heavily depends on the local situation. It will also differ between groups of individuals but even an rough estimate is of value if one wants to do an overall calculation of the risk of infection. Naturally, this risk based on the exposure value will differ dependent on the prior treatment. This part is heavily linked with the occurring practices.

Groups Affected

In addition, different user and non-user groups may be affected. In this context these groups can be defined as users, workers, farmers and the community. Special consideration should be given to vulnerable groups like children, the elderly or people with other underlying disease.

A USER is the person who uses the technology on a regular basis.
A WORKER is a person who is responsible for maintaining, cleaning, operating or emptying the technology. However to avoid ambiguity, the emptying of a given technology is not addressed in the technology description, but is considered under the Function group ‘conveyance’.
A FARMER is the person who is using the products generated (though that could be the same person as the user or the worker, for example, if the same person uses, cleans, empties and applies the products the different parts of the sanitation system. This group is only applicable to the category of use and/or disposal.
A COMMUNITY includes anyone who is living near to, or downstream from the technology, and may be passively affected. ‘Community’ also includes anyone who consumes products (for example crops or fish) that are produced using sanitation products.

Mitigating Health Risks

Sanitation is considered as a system comprising technical (functional groups) and non-technical components that work in synergy to safeguard human health. Each sanitation technology is related to this grouping or components.

Technologies are defined as the specific infrastructure, methods, or services that are designed to contain, transform, or transport products to another functional group or component. Five main functional groups make up a full sanitation systems. These are

user interface (e.g. toilet systems)
storage and treatment
conveyance collection
secondary treatment
disposal and/or reuse

Each of the functional groups may be represented by different technologies that are chosen depending on the local context. The selected technology within each of the functional groups will govern the overall reduction efficiency and the likelihood of disease transmission. Each is linked to critical points where pathogens may be transmitted or controlled (see also toilet systems).

Non-Technical Aspects

Furthermore, the extent of human health protection by the sanitation system relates to non-technical socio-cultural aspects linked to specific features of the system, e.g. traditions, local believes, behaviours or taboos, or also predominant hygiene practices. These may further reduce (or sometimes elevate) exposure to pathogens at these critical points or as end-use related risks.

An example of such socio-cultural aspects are the Koranic edict where excreta are regarded as impure (najassa) and its use only permitted when the najassa is removed (FARUQUI 2001). Similarly, the Luo of western Kenya dispose of children’s faeces by digging and burying. This further relates to raining. Infants are trained to defecate in a special place and inform their care-takers so that the faeces are disposed of (ALMEDOM 1996) (see also sociocultural issues).

This picture was taken by Robert Gensch during Global Handwashing Day 2008 activities and the simultaneous launching of the Essential Health Care Package (EHCP) for Filipino Children (includes handwashing, tooth brushing and twice a year deworming). Source: SuSanA on Flickr (2008)

Cultures or traditions may also involve perception that exposes people to disease causing pathogens. This is the situation with child faeces which in other cultures are perceived as harmless, also when diarrhoeal diseases are prevalent. When mothers in areas with high prevalence of childhood diarrhoea are asked about the cause of the disease, they often blame it another factors than the poor handling of child faeces or poor hand washing practices (see also hygiene frameworks and approaches).

References

ALMEDOM, A. (1996): Recent Developments in Hygiene Behaviour Research: An Emphasis on Methods and Meaning. Tropical Medicine and International Health. PDF

CURTIS, V.; CAIRNCROSS, S. (2003): Effect of Washing Hands with Soap on Diarrhoea Risk in the Community: A Systematic Review. Lancet Infect Dis.

FARUQUI, N.; BISWAS, A.; BINO, M. (2001): Water Management in Islam. Tokio, New York, Paris: IDRC and UNU Press.

STENSTROEM, A.; SEIDU, R.; EKANE, M.; ZURBRUEGG, C. (2011): Microbial Exposure and Health Assessments in Sanitation Technologies and Systems. Stockholm: Stockholm Environment Institute (SEI). URL [Accessed: 28.11.2011]. PDF

CARR, R. (2001): Excreta-related Infections and the Role of Sanitation in the Control of Transmission. In: FEWTRELL, L. ; BARTRAM, J. (2001): Water Quality: Guidelines, Standards and Health. London, 89-113. URL [Accessed: 06.10.2010].

Further Readings

A detailed chapter of an online book which highlights the possible routes of diseases transmission as well as possible measures which could stop the transmission of diseases. The improvement of sanitation system plays an important role if the transmission should be interrupted.

PEASEY, A. (2000): Health Aspects of Dry Sanitation with Waste Reuse. London: London School of Hygiene and Tropical Medicine. URL [Accessed: 06.10.2010]. PDF

This review compiles current knowledge on health risks which are associated with dry sanitation systems and the use of the products as well as their maintenance. It contains also a survey on the application of dry sanitation systems in Mexico which is considered as one of the countries with the most dry sanitation toilets.

ROMA, E.; PUGH, I, (2012): Toilets for health. London: London School of Hygiene & Tropical Medicine. URL [Accessed: 27.11.2012]. PDF

This is a comprehensive report on why toilets matter. The report is rich in infographics, provides overview of the sanitation crisis and the related burden of disease in developing countries.

SCOTT, R. (2006): Should Ecological Sanitation Carry a Health Warning? Assessing the Health Risks of Ecological Latrines. Loughborough: Water Engineering and Development Centre (WEDC). URL [Accessed: 06.10.2010]. PDF

An assessment of the risk of ecological latrines. Risks can be reduced through a proper application and a couple of simple measures.

STENSTROEM, T.A. (n.y.): Breaking the sanitation barriers; WHO Guidelines for Excreta Use a as Baseline for Environmental Health. Solna: Swedish Institute for Infectious Disease Control. URL [Accessed: 06.10.2010]. PDF

A short paper about the safe use of excreta. The paper includes a summary of problems caused by untreated water and gives a short review of targets which could be reached in the future.

TOUBKISS, J. (2010): How to Manage Public Toilets and Showers. Cotonou and Paris: Partenariat pour le Développement Municipal (PDM) and Programme Solidarité Eau (pS-Eau). URL [Accessed: 19.10.2011]. PDF

The purpose of this decision-making aid is to provide practical advice and recommendations for managing toilet blocks situated in public places. It is primarily aimed at local decision-makers in developing countries and at their partners (project planners and managers).

WHO (Editor); UNICEF (Editor) (2012): Toolkit for monitoring and evaluating household water treatment and safe storage. Geneva: World Health Organization. URL [Accessed: 08.11.2012]. PDF

In order to develop effective mechanisms to encourage and sustain correct use of household water treatment and safe storage (HWTS), there is a need to monitor and evaluate uptake. The Toolkit provides an overall framework for this. One of the key features is the presentation of 20 harmonized, global indicators to assess correct and consistent use of household water treatment and safe storage by those most at risk.

WHO (Editor); UNICEF (Editor) (2012): Rapid assessment of drinking-water quality. A handbook for implementation. Geneva: World Health Organization. URL [Accessed: 08.11.2012]. PDF

This handbook describes the methods and procedures of the Rapid assessment of drinking-water quality (RADWQ) applied by WHO and UNICEF to explore the quality of drinking-water from "improved" sources in five countries. The handbook is for adoption by any authority or institution that wants to prepare a snapshot of the quality of "improved" sources of drinking-water, as a first step towards strengthening drinking-water quality regulations.

WSP (Editor) (2012): Behavioral Determinants of Handwashing with Soap Among Mothers and Caretakers: Emergent Learning from Senegal and Peru. Washington, D.C: Water and Sanitation Program (WSP). URL [Accessed: 27.02.2012]. PDF

A new Water and Sanitation Program (WSP) Learning Note found that beliefs and ease of access to soap and water were correlated with handwashing with soap behaviors for given proxy measures among mothers and caretakers in Peru and Senegal.

ZURBRUEGG, C. (2008): Sanitation Systems, Technology Options, Hygiene and Health. Duebendorf: EAWAG. URL [Accessed: 06.10.2010]. PDF

A short presentation, which contains a collection of present knowledge. This includes strategies, goals and an overview about the best use of excreta products.

WORLD BANK (2013): Handwashing With Soap Toolkit. Washington: World Bank. URL [Accessed: 15.05.2013].

This toolkit, intended for practitioners interested in behavior change, is organized into four modules: Behaviour Change, Sustainability, Integration and Results. Each has reports and presentations about the lessons learned from previous projects, as well as mass media, direct consumer contact, and interpersonal communication tools used throughout previous projects.

Case Studies

GILL, S.; HAYES, J.; COATES, S. (2012): DIARRHOEA DIALOGUES From Policies to Progress. A call for urgent action to prevent the biggest killer of children in sub-Saharan Africa. Teddington and Washington, D.C.: Tearfund and Path. URL [Accessed: 30.05.2012]. PDF

This review looks at the policy environment for diarrhoea control in three African countries, in order to glean lessons learnt about what more we can do to address this problem. While solutions are available to prevent and treat diarrhoea, the political will and health prioritisation are still lacking to make these solutions widely available to those who need them most. To accelerate progress in cutting mortality from diarrhoea, global and national decision-makers need to take urgent action.

Awareness Raising Material

HESPERIAN FOUNDATION (Editor); UNDP (Editor) (2004): Sanitation and Cleanliness for a Healthy Environment. Berkeley: The Hesperian Foundation. URL [Accessed: 17.04.2012]. PDF

This book contains well-written information about both personal and public cleanliness including instructions on how to build safe toilets that respect the principles of sustainable Sanitation. The book is also available in Spanish and Creole.

RHEINGANS, R. (Editor); CUMMING, O. (Editor); ANDERSON, J. (Editor); SHOWALTER, J. (Editor) (2012): Estimating Inequities in Sanitation-related Disease Burden and Estimating the Potential Impacts of Propoor Targeting. London: London School of Hygiene and Tropical Medicine. URL [Accessed: 16.03.2012]. PDF

The objectives of this study are to model for 10 low-income countries in sub-Saharan Africa and South Asia: 1) The distribution of sanitation-related health burden by wealth quintile; 2) The distribution of health benefits for targeting different wealth quintile groups; 3) The spatial distribution of sanitation-related health burden and benefits

Training Material

EAWAG (Editor); SANDEC (Editor) (2008): Environmental Health. Lecture notes. Duebendorf: Swiss Federal Institute of Aquatic Science (EAWAG), Department of Water and Sanitation in Developing Countries (SANDEC). URL [Accessed: 23.05.2012]. PDF

This book contains information on environmental health aspects of water and sanitation. It contains a definition of environmental health, describes various water-related diseases and also hygiene approaches. There is also a related PowerPoint to this document.

EAWAG (Editor); SANDEC (Editor) (2008): Environmental Health. Presentation. Duebendorf: Swiss Federal Institute of Aquatic Science (EAWAG), Department of Water and Sanitation in Developing Countries (SANDEC). URL [Accessed: 23.05.2012]. PDF

This PowerPoint presentation contains information on environmental health aspects of water and sanitation. It contains a definition of environmental health, describes various water-related diseases and also hygiene approaches. There is also a related lecture to this document.

HOUSE, S.; MAHON, T.; CAVILL, S. (2012): Menstrual hygiene matters. A resource for improving menstrual hygiene around the world. London: WaterAid. URL [Accessed: 29.01.2013]. PDF

Menstrual hygiene matters is an essential resource for improving menstrual hygiene for women and girls in lower and middle-income countries. Nine modules and toolkits cover key aspects of menstrual hygiene in different settings, including communities, schools and emergencies.

RICHERT, A.; GENSCH, R.; JOENSSON, H.; STENSTROEM, T.A.; DAGERSKOG, L. (2010): Practical Guidance on the Use of Urine in Crop Production. Stockholm: Stockholm Environment Institute (SEI). URL [Accessed: 20.07.2010]. PDF

This practical guideline on the use of urine in agricultural productions gives some background information on basic plant requirements and how they can be met with urine as a liquid fertiliser.

SCHOENNING, C.; STENSTROEM, T.A. (2004): Guidelines on the Safe Use of Urine and Faeces in Ecological Sanitation Systems. Stockholm: Stockholm Environment Institute (SEI). PDF

These guidelines provide a thorough background on the safe use of urine and faeces for agricultural purposes. Aspects like the health risk associated we the use of human excreta in agriculture and how to limit them are discussed.

Important Weblinks

http://www.who.int/ [Accessed: 27.10.2010]

This website contains an abridged and revised second information kit on the guidelines for the safe use of wastewater, excreta and greywater in agriculture and aquaculture.

http://www.who.int/ [Accessed: 27.10.2010]

This is the link to all four WHO guidelines on the safe use of wastewater, excreta and greywater for agriculture: Volume 1 discusses policy and regulatory aspects; Volume 2 presents guidelines for wastewater use in agriculture; Volume 3 highlights guidelines for wastewater and excreta re-use in aquaculture; Volume 4 contains the guidelines for excreta and greywater re-use in agriculture.

http://maternalhealthtaskforce.org/wash-and-womens-health/ [Accessed: 18.03.2013]

Blog on issues relating to Water, Sanitation and Hygiene (WASH) with a focus on women’s health.