Water Contamination Problems by Drinking water contaminants: Arsenic Contamination, Fluoride Contamination

The Arsenic Problem

The provision of clean, wholesome water is a fundamental requirement for a healthy life. Sadly, in many countries this is a major problem because of a variety of reasons, be they chemical or bacteriological. In many countries, to avoid health problems from water borne bacteria, tube wells have been sunk to aquifers containing water free from such micro-biological contaminants. In some instances, these aquifers have been found to contain water with high arsenic levels. This arsenic contamination invariably arises from natural geological and environmental conditions. Arsenic arises in many ores and minerals and is frequently present in combination with iron and manganese oxides; under various natural conditions it can be rendered soluble and released into the groundwater. This problem is experienced in widespread regions across the globe: Argentina, Bangladesh, Hungary, India (West Bengal), Mongolia, Northern China, Thailand, UK, USA (Arizona, Illinois, New Hampshire, New Mexico, Southern California). The problem is especially acute in the Ganges delta region, where the arsenic is believed to be associated with the iron and manganese oxides in the alluvial sediments. In Bangladesh and West Bengal some 35 million people drink water from wells where the arsenic level in the water exceeds the Bangladesh/Indian standard (0.05mg/l). If the proposed new World Health Organization guideline (0.01mg/l) were adopted then a further 20-25 million people are likely to be included. The scale of the disaster in Bangladesh is greater even than the accidents in Bhopal and Chernobyl (WHO, 2000).

Prolonged exposure to arsenic can cause very serious health problems. Exposure to arsenic has been identified as a long-term cause of skin lesions, gangrene, cardiovascular disease, pulmonary disease, neurological disease, hypertension, peripheral vascular disease, diabetes mellitus, skin cancer, bladder cancer, lung cancer and cancer of the kidneys. In high concentrations, arsenic poisoning can also lead to an acute condition called arsenicosis.

Further background on the problem can be found at http://www.bgs.ac.uk/arsenic/bphase1

The Fluoride Problem

Fluoride is a major, naturally occurring contaminant in drinking water in many regions of the world. At low levels, say 1mg/l, it is found to be beneficial in preventing dental caries. However, exposure to high levels can cause structural tooth damage and at a high enough level can cause skeletal damage. Certain areas of India and China have very high levels giving rise to major health problems.

In India, over 66 million people, including 7 million children, in 17 States out of the 32 States and Union Territories are afflicted with endemic Fluorosis. There is no specific treatment for endemic Fluorosis apart from drinking water free from fluoride.