Pit latrines are one of the most common human excreta
disposal systems globally, and their use is on the rise as countries aim to
meet the sanitation-related target of the Millennium Development Goals (MDGs).
Strong evidence supports the use of these basic toilets as a
way to improve human health. However, improperly designed pit latrines can
actually allow disease-causing microbes or other contaminants to leach into the
groundwater. The contaminated water puts people, and especially children, at
risk of developing potentially life-threatening diarrhoeal diseases.
How the research was
A new study by Jay Graham, PhD, MBA, MPH, an assistant
professor in the Department of Environmental and Occupational Health at the
George Washington University School of Public Health and Health Services
(SPHHS) in collaboration with Matthew Polizzotto of North Carolina State
University first estimates the number of people worldwide that rely on pit
latrines. The study goes on to identify some key knowledge gaps that could be
addressed to keep the drinking water safe and protect the public.
Using survey data, the researchers calculated that an
estimated 1.77 billion people around the globe use pit latrines, a step up from
places that have no sanitation facilities. In the countries where pit latrines
are common, the study suggests that more than 2 billion people rely on the
groundwater for their primary source of drinking water.
Despite the risk of widespread contamination of the water
from improperly designed or poorly located pit latrines, the researchers found
there are very few studies on this risk. Graham and Polizzotto reviewed the
scientific literature and found that the studies that have been done on this
topic are small and limited in scope.
The researchers conclude that much more needs to be done to
identify technologies that can be used to protect the groundwater from
contaminants coming from pit latrines. In addition, the team says that more
work must be done to understand the impact of global warming on coastal areas
of developing countries. If global warming results in flooding of regions
relying on simple pit latrines the end result could be widespread contamination
of the environment, Graham says.
"Poorly built pit latrines or those that are sited
improperly can be a human health risk," Graham said. "Additional
research could identify technologies and guidelines that might help developing
countries build safer pit latrines."
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