Feature N° 203
WATER - TOO MUCH OR TOO LITTLE - THE FOREMOST CAUSE OF NATURAL DISASTERS
Almost two billion people – one-third of humanity –were affected by natural disasters in the last decade of the 20th century. Floods and droughts accounted for 86% of them.
Quick-onset disasters like earthquakes, volcanic eruptions and landslides may be more dramatic and take a very high toll in human lives. But floods and droughts – too much water or too little – often have longer lasting and more far-reaching effects on the health of their victims.
"The most vulnerable victims are the poor and the marginalized, most of whom live in low-quality housing in flood-prone or drought-prone regions," says Jamie Bartram, Coordinator of the World Health Organization’s Water, Sanitation and Health Programme. "In periods of drought, their desperate search for water leads them to drink contaminated water and fail to exercise personal hygiene. And those fleeing floods often drink unclean water too.
"If the drinking water supply and the sanitation systems are already inadequate, flooding poses a major health threat. Inundated industrial waste, such as used engine oil and refuse dumps add to health risks. People who have lost everything in the flood – their homes, their food, their livelihood – are all the more vulnerable to disease."
Floods are the second most frequent cause of natural disaster after windstorms, but affect more regions and more people than any other phenomenon. Drought is the largest cause of death because it often leads to famine.
"Statistical studies indicate that floods are becoming more frequent," says Jamie Bartram. "From 66 major floods in 1990 the number rose in 1999 to 110. The number of people who died in floods in 1999 was more than double the number killed by floods in any other year in the decade of the 1990s. All this is happening on an increasingly crowded planet. And while the world’s leaders continue to debate long-term solutions, related, for example, to climate change, what are most needed are better preparedness and better prevention measures, especially in the Least Developed Countries (LDCs), and more generally for the vulnerable poor."
With recent or current floods in Poland, Indonesia, the Mississippi Valley, Zimbabwe, Siberia, Angola, Brazil, north-eastern France, Peru, and with drought in Afghanistan, Cuba, Florida, the Horn of Africa, central Asia, the south-western United States of America, and the United Kingdom, the media spotlight is on these two natural disasters. One unfortunate region, the poor Indian state of Orissa, experienced massive flooding last year, followed this year by the worst drought in a decade and new floods. Around 27 million people out of a population of 32 million have already been affected.
Notwithstanding the magnitude and widespread geographical distribution of floods and drought, a great deal can be done to prevent or mitigate their adverse effects on health. Clean, safe water is the key.
Simple, practical measures such as teaching people how to conserve water and keep it safe from contamination and how to store emergency supplies of safe drinking water will go a long way to helping communities at risk. Chlorination is known to reduce diarrhoea, cholera and other diseases.
A four-month study of water contamination in a Malawi refugee camp, where there had been repeated outbreaks of cholera and diarrhoea, showed that the water flowing from source wells had little or no microbial contamination, but that refugees collecting the water quickly contaminated it, primarily through contact with their hands. The introduction of a simple improved container for collecting the water resulted in a 69% reduction in faecal coliform levels in household water and 31% less diarrhoeal disease in children under five years of age among those who used the improved bucket.
In tropical countries receding floodwaters provide an ideal breeding ground for mosquitoes, and create an increased risk of such diseases as malaria, dengue and Rift Valley fever. Floodwater combined with effects of open sewage and reduced opportunities for good personal hygiene, lead to cholera, diarrhoea and gastrointestinal viruses and displace rodent populations which can cause outbreaks of leptospirosis and hantavirus infection.
Early warning systems to detect rises in mosquito-borne and diarrhoael diseases and to evaluate the risk of floods and drought also need to be set up. Sanitation in many regions should be improved because countries with a good infrastructure for drainage and disposal of human waste have far fewer direct health problems during water-related disasters. Most important, however, is helping local communities themselves to prepare for and respond to these disasters.
Flooding is visible to everyone, but drought is a great deal more difficult to recognize. When does a dry spell in fact become a drought? Unlike a typhoon or an earthquake, a drought may cover a large geographical area and take months or even years to develop. Decision-makers may put off acting until the effects are dramatic, and that could be too late to do anything effective.
Drought triggers or exacerbates malnutrition and famine. Accurate statistics for droughts are hard to come by because deaths are mainly due to lack of food and the worsening of pre-existing malnutrition, but also to migration, homelessness, damage to public health infrastructure, to water distribution and to health care. In hot countries or during heat waves deaths may be caused by a combination of heat and shortage of water.
Note to journalists: for more information or interviews please contact: Jamie Bartram, WHO, Coordinator, Water, Health and Sanitation Unit, WHO, Geneva. Telephone (+41 22) 791 3537, E-mail:email@example.com; Paul Ress, Media Consultant, Geneva. Telephone (+41-22) 734. 9813, E-mail: firstname.lastname@example.org; Nada Osseiran, Project Manager, WHO, Geneva. Tel: (+41 22) 791 4475, Fax: (+41 22) 791 4159 E-mail: email@example.com
All WHO Press Releases, Fact Sheets and Features as well as other information on this subject can be obtained on Internet on the WHO home pagehttp://www.who.int/ and on www.worldwaterday.org