Unnecessary and Deadly: The Post-Disaster Catastrophe of Waterborne Diseases

Too often, the death toll caused by flood waters is measured in terms of the initial drowning and trauma victims. Yet the death toll does not plateau after the waters have receded. Waterborne diseases often wreak havoc on victims who have already suffered great loss, particularly in developing nations. Preventing these diseases from occurring requires solutions which are not so much scientific as they are infrastructural, entailing many of the practices used for flood relief in general. These solutions necessitate long-term commitments, individual state preparations, and international reactions.

Clean water is an aid item even more essential than food after a disaster: the human body can survive for weeks without food but only for about three to five days without water [1]. Unfortunately, flood victims often have no access to clean water, because of the destruction or absence of sanitation facilities, or problems with the distribution of water supplies. Worse, there is often general ignorance about the dangers of waterborne disease. All of these factors place survivors of floods at a great risk. As thirst becomes intolerable, a basic need of life becomes a hazard, and even people who are aware of the risk are compelled to disregard it because they do not know how to render water safe for use. For example, in the aftermath of the Bangladesh floods in 1998, 75% of the victims interviewed who drank from rivers or wells said that they believed the water was contaminated [2].

When heavy flooding occurs, sewage and industrial chemicals mingle in a dangerous microbial soup. Increased volumes of water can change the direction of its flow or divert its course, so that it runs through dung fields, or other places where pathogens are present. The growth of plankton and bacteria increases from the presence of chemical nutrient sources in the water, which will stagnate or flow into rivers, tainting them [3].

Water can transmit disease in a variety of ways. The various illnesses which humans can contract by drinking tainted water can be placed into three main categories according to the causative agent: protozoal, bacterial, and viral. The diseases which are among the most common and the earliest to have an effect are diarrhea-related diseases such as dysentery and cholera, which ironically can lead to death by dehydration [4]. External contact with tainted water can be enough to cause serious health problems. Microbes can enter the body not only by hand to mouth, but through mucus linings, such as through the nasal passages, down the respiratory tract, wounds and broken skin, and corneal contact [5]. There are numerous diseases and conditions, such as dermatitis, respiratory problems, and gastrointestinal ulcers, which are the result of casual contact with the water by wading or swimming [3]. Indeed, those who swim through muddy water to save someone’s life may compromise their own.

Many factors can magnify the impact of waterborne disease. Exposure to the contaminated water in disaster scenarios comes at a time when immune systems are most likely already impaired due to lack of food and exposure to the elements due to lack of shelter. Floods demolish preexisting infrastructure, including water treatment centers and medical facilities. The gravity of the situation also depends partly on the prevalence of the microorganisms prior to floods, which is difficult to control [2]. But it depends additionally on population density and the amount of people displaced [6]. Makeshift camps are usually crowded, and when the newly homeless pour into established towns and urban areas, the communicability of diseases is increased [6].

Often, the most serious humanitarian crises occur in developing nations such as Pakistan and Bangladesh where general poverty and a lack of infrastructure exacerbate the problems affecting disaster areas. When these poorer countries are affected, another concern is the widespread ignorance of the risks associated with drinking untreated water, especially among children. Citizens of these nations, whose standard of living is low, are also usually unable to wash their hands in clean water and lack proper latrines [7]. In these environments there are greater probabilities of fecal matter mixing into waters [2].

All of these dilemmas may find solutions in two sources: the governments of stricken countries and outside aid. Disasters and humanitarian crises give the domestic governments and the international community the opportunity − indeed, the responsibility − to take action. But these are reactive steps – responses to crisis. Even before a crisis can befall a nation, as a preventative measure, the populace should, once aware of the risk present in water, be educated about the necessity of taking simple steps to render water safe for drinking.

These steps are numerous and not at all difficult. Boiling water has long been known to destroy the potency of microbes. When obtaining firewood is a problem, purification tablets are an essential part of aid packages [8].  Bleach added thirty minutes prior to drinking may change the taste of the water, but is an effective disinfectant [8]. Recently, electrolysis cells which can produce a disinfecting solution, sodium hypochlorite, from salt and water have been developed [8]. Inexpensive and easy to use, these cells can run on solar power [9]. On a far simpler note, covering jars prevents microbe entry [2, 7].

Another preventative measure that governments in particularly flood-prone areas can, where possible, take to preserve both supplies of clean water and the means of rendering water clean, is enforcing construction laws. Currently, during the reconstruction process, buildings are often recreated by aid groups using the same methods as before [10]. Sturdily built housing and infrastructure will minimize the damage to water treatment and sewage plants [10]. A smaller displaced population would mean less crowding in temporary shelters, and decrease the likelihood of disease transmission.

In the midst of a massive crisis, the government can only do so much on its own. The international aid response after the disaster also needs to be prompt and sustained. One would think that any country would, out of compassion for humanity, participate in relief efforts. One would also think that the government would work in conjunction with outside aid groups as much as possible in an emergency. This may not always be the case. An example that is both recent and illustrates this point well is Pakistan.

Pakistan was already a country which had problems establishing and maintaining a clean water supply. About thirty percent of yearly deaths in Pakistan were from waterborne disease, two hundred fifty thousand being of children [11]. The 2010 floods exacerbated the problem, and now ten million, according to the United Nations (UN), are at risk of drinking contaminated water. Despite the urgency of the situation and calls from the UN for millions, the arrival of aid is slow. Pledges to donate are not fulfilled [12].This may be due to fears over the instability of Pakistan. Indeed, there are areas with records of violent outbreaks where the government has restricted aid groups from access, including flying in aid [13]. The national army must provide for these areas alone, and by itself is having difficulty reaching everyone [10]. Yet there is no reason to deny a country aid due to problems in certain areas. Perhaps potential donors fear the use of funds to support violent activity. But reducing the impact of waterborne diseases on post flood death tolls is already a weighty task without the international community seizing upon reasons for half-hearted aid campaign participation.

The elimination of, or at least the drastic reduction of, water-borne illnesses seems to be an insurmountably difficult goal, with a multi-part solution too wide in range to implement. However, the basic science behind the prevention of such diseases is little more than germ theory. With international cooperation and national government action, the incidence of post-disaster waterborne diseases can be lessened when preventative measures are implemented.


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  8. [WHO] World Health Organization. Flooding and communicable diseases fact sheet: Health action in crises. WHO; 2010 [cited 5 Nov 2010]. Available from http://www.who.int/hac/techguidance/ems/flood_cds/en/.
  9. Mintz E, Reiff F, Tauxe R. Safe water treatment and storage in the home: A practical new strategy to prevent waterborne disease. JAMA 1995; 273: 948-953.
  10. Alertnet, Reuters Foundation. Floods. 2010 Jun 7 [cited 5 Nov 2010]. Available from http://www.alertnet.org/db/crisisprofiles/floods.htm.
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  12. OCHA. Pakistan – Flood – July 2010. Table A: List of all commitments/contributions and pledges as of 02 December 2010. 2010 Dec 02. Available from http://fts.unocha.org/reports/daily/ocha_R10_E15913_asof___1012020204.pdf.
  13. M Rowling. Alertnet, Reuters Foundation. Hundreds of thousands in flood-hit Pakistan may never get aid. 2010 Oct 28 [cited 30 Nov 2010]. Available from http://www.trust.org/alertnet/news/interview-hundreds-of-thousands-in-flood-hit-pakistan-may-never-get-aid-icrc/.

Niloufar is a first-year at the University of Chicago majoring in biology.

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  • The various illnesses which humans can contract by drinking tainted water can be placed into three main categories according to the causative agent: protozoal, bacterial, and viral. The diseases which are among the most common and the earliest to have an effect are diarrhea-related diseases such as dysentery and cholera, which ironically can lead to death by dehydration [4]. External contact with tainted water can be enough to cause serious health problems. Microbes can enter the body not only by hand to mouth, but through mucus linings.