Sanitation and health: partners to achieving sustainable development

Hello. My name is Lawrence Gill and I am a Professor of Environmental Engineering at Trinity College Dublin. My research focuses on exploring provision and sustainability of clean water and sanitation around the globe. I have a particular interest in how contaminants from human activities move through the environment and how they can pose a risk to both human health and natural ecosystems. I’ve been involved in understanding and researching sustainable sanitation projects in places as diverse as Ireland, Tanzania, India, Niger, and South Sudan. This week, we’re going to be investigating the impact of SDG 6 clean water and sanitation. And you may be wondering why we are focusing on this particular goal.

This vital SDG is interlinked with almost all of the other goals. But in particular, it has a major influence on what you were learning last week with Martina, good health. Between 1990 and 2015, 2.6 billion people gained access to improved sources of drinking water with 2.1 million people getting access to improved sanitation. However, around 660 million people still use unsafe drinking water sources. And more worryingly, 2.4 billion people still lack access to improved sanitation. Over 840,000 people in low and middle income countries die as a result of inadequate water, sanitation, and hygiene each year. Water and sanitation-related diseases, such as cholera, typhoid, and diarrheal diseases challenge many of the sustainable and development goals.

If we don’t seek to attain the goal of clean water and sanitation, other goals, such as health care, poverty, economic growth, and sustainable cities, will never be reached. But we also have to think about the sustainability of projects related to clean water and sanitation in relation to local communities and the environment. In this step, we are going to focus on the impact of clean water and sanitation on last week’s goal good health. Poor public health related to water-based diseases is long rooted in human history. Before we look into the issues that we are facing today we’re going to look back on the history of sanitation and how it became an essential part of understanding how diseases are transmitted.

In the mid 19th century, scientists believed that diseases such as the Black Death and cholera were caused by what they termed myasthma or a noxious form of bad air. But this thinking was transformed following the London cholera epidemic in 1854 by John Snow, an English physician, who noticed a spread of one outbreak of disease seemed to be centred around a water pump. When the council removed the pump handle the epidemic appeared to slow down. Our germ theory of disease is embedded in this notable event and is known as the founded event of the science of epidemiology.

Well though it took some years for this theory to be fully accepted, European cities started to construct sewerage systems to remove the wastewater from the streets and local water courses. In London, an extensive sewage system was designed by a civil engineer, Joseph Bazalgette, in 1858. This sewage system diverted waste from the city much further out to the Thames estuary, downstream of the main centre of population. Thus significantly helping to improve public health in the city. Later, the negative impacts of discharging such wastewater on the environments, i.e. Into the rivers, lakes, or the sea, were also realised.

So the focus of dealing with such waste has progressed from just targeting public health in cities by removal of the waste to somewhere else to thinking about how best we can manage the impacts of effluent being discharged into the natural environment. This requires the treatment of wastewater in specialised unit processes, which target reduction of different compounds, such as removal of organics, ammonia, phosphorus, et cetera. Focusing on public health, it is important to understand how diseases linked to provision of water and disposal of wastewater can be spread and how the provision of clean water, effective sanitation, and hygiene are intractably linked to public health.

It is obviously important that the water we drink and use for cooking, washing, et cetera is free from harmful microorganisms and chemicals. But it is equally important that the waste we dispose of, which may contain these harmful microorganisms and chemicals, does not pollute the water supplies. Our personal hygiene activities linked to the use of water are also critical to ensure good public health. It is counter-productive to provide a high quality of water from a well, for example, if it is then carried back to a house and left to stand in a place where it can be polluted before it is consumed.

Hence, all three elements– safe water, improved sanitation, and hygiene– need to be addressed at the same time for the optimum improvement and protection of public health. One important area where this can be seen is when diseases manifest in our water cycle.