Lessons to be learned

The discovery of arsenic contamination of ground-water in many nations, including Argentina, Chile, China, India, Mexico, Taiwan, Thailand, the United States and, now, Bangladesh shows that this is a global problem. All groundwater sources used for drinking-water should be tested for arsenic. A retrospective look at the situation in Bangladesh is instructive in that a declaration of a public health emergency might have expedited a more rapid response to the problem. In the three years after the original consultancy in Bangladesh for WHO (3–5), the rapid intervention team has only reached a few hundred villages. Millions of wells and people remain to be tested and examined. This experience in Bangladesh has reinforced the importance of using organizations and systems that are already in place in the affected area. When a rapid response to a health emergency is needed, it is not the time to reorganize or implement completely new systems. Rather, it is the time to take advantage of existing governmental and nongovernmental organizations, which already have contacts in the field and can thus respond quickly. The rapidity of the response is crucial - the longer the exposure continues, the greater the likelihood of disease.

Contamination of drinking-water with arsenic further illustrates the difficulties of community-based interventions. It is likely that a single visit to a village, during which the water is tested and the nearest well painted red, will not have a long-term impact on the behaviour of members of the community, particularly if none of the villagers has any signs of arsenic-caused disease. Habits are difficult to break; one visit will not be convincing when the villagers look at the clear, clean water.

Follow-up monitoring and education are integral to sustaining the impact of the first intervention and to safeguarding the population's health.

Most importantly, the arsenic contamination of groundwater in Bangladesh has indicated that delaying action in an attempt to be thorough in research and long-term planning can be a mistake. Long-term solutions will likely have to be tailored to local environments, and it is counterproductive to defer immediate action until the long-term alternatives are completely designed. The cause of arsenicosis is clear and continuing exposure increases the risk of non-fatal outcomes and death; these diseases can be eradicated at relatively low cost. In such a situation, the worst thing that can possibly be done is nothing.