Example: confidence

Allan H. Smith, Elena O. Lingas, & Mahfuzar Rahman

Contamination of drinking-water by arsenicin bangladesh : a public health emergencyAllan H. Smith, 1 Elena O. Lingas, 2& Mahfuzar Rahman3 The contamination of groundwater by arsenic in bangladesh is the largest poisoning of a population in history, withmillions of people exposed. This paper describes the history of the discovery of arsenic in drinking-water inBangladesh and recommends intervention strategies. Tube-wells were installed to provide pure water to preventmorbidity and mortality from gastrointestinal disease. The water from the millions of tube-wells that were installedwas not tested for arsenic contamination. Studies in other countries where the population has had long-termexposure to arsenic in groundwater indicate that 1 in 10 people who drink water containing 500mg of arsenic perlitre may ultimately die from cancers caused by arsenic , including lung, bladder and skin cancers.

Contamination of drinking-water by arsenic in Bangladesh: a public health emergency Allan H. Smith,1 Elena O. Lingas,2 & Mahfuzar Rahman3 ...

Tags:

  Bangladesh, Arsenic

Information

Domain:

Source:

Link to this page:

Please notify us if you found a problem with this document:

Other abuse

Transcription of Allan H. Smith, Elena O. Lingas, & Mahfuzar Rahman

1 Contamination of drinking-water by arsenicin bangladesh : a public health emergencyAllan H. Smith, 1 Elena O. Lingas, 2& Mahfuzar Rahman3 The contamination of groundwater by arsenic in bangladesh is the largest poisoning of a population in history, withmillions of people exposed. This paper describes the history of the discovery of arsenic in drinking-water inBangladesh and recommends intervention strategies. Tube-wells were installed to provide pure water to preventmorbidity and mortality from gastrointestinal disease. The water from the millions of tube-wells that were installedwas not tested for arsenic contamination. Studies in other countries where the population has had long-termexposure to arsenic in groundwater indicate that 1 in 10 people who drink water containing 500mg of arsenic perlitre may ultimately die from cancers caused by arsenic , including lung, bladder and skin cancers.

2 The rapidallocation of funding and prompt expansion of current interventions to address this contamination should befacilitated. The fundamental intervention is the identification and provision of arsenic -free drinking water. arsenic israpidly excreted in urine, and for early or mild cases, no specific treatment is required. Community education andparticipation are essential to ensure that interventions are successful; these should be coupled with follow-upmonitoring to confirm that exposure has ended. Taken together with the discovery of arsenic in groundwater inother countries, the experience in bangladesh shows that groundwater sources throughout the world that are usedfor drinking-water should be tested for : bangladesh ; arsenic poisoning, prevention and control; arsenic poisoning, therapy; water pollution,chemical, prevention and control; water treatment; environmental page 1100 le re sume en franc ais.

3 En la pa gina 1101 figura un resumen en espan is grappling with the largest masspoisoning of a population in history because ground-water used for drinking has been contaminated withnaturally occurring inorganic arsenic . It is estimatedthat of the 125 million inhabitants of Bangladeshbetween 35 million and 77 million are at risk ofdrinking contaminated water (1,2). The scale of thisenvironmental disaster is greater than any seenbefore; it is beyond the accidents at Bhopal, India,in 1984, and Chernobyl, Ukraine, in 1986. This papersuggests guidelines for responding when a popula-tion is exposed to arsenic , and it is based oninformation from several visits to bangladesh madeby Allan H.

4 Smith as a consultant for the WorldHealth Organization between 1997 and 1998 (3 5).In 1983, the first cases of arsenic -induced skinlesions were identified by Saha then at theDepartment of Dermatology, School of TropicalMedicine in Calcutta, India (6). The first patients seenwere from West Bengal, but by 1987 several hadalready been identified who came from neighbouringBangladesh. The characteristic skin lesions includedpigmentation changes, mainly on the upper chest,arms and legs, and keratoses of the palms of thehands and soles of the feet (Fig. 1). After ruling outother causes, water sources used by the patients wereanalysed, and the diagnosis of arsenic -caused diseasewas confirmed.

5 The primary drinking-water sourcesfor the patients were tube-wells, which drew waterfrom underground aquifers (Fig. 2 )(6).Tube-wells have been used in bangladesh sincethe 1940s (7). However, the problem of arsenic -contaminated water has only recently come to lightdue to the increasing number of tube-wells used overthe past 20 years and the subsequent increase in thenumber of individuals drinking from them. Histori-cally, surface water sources in bangladesh have beencontaminated with microorganisms, causing a sig-nificant burden of disease and mortality. Infants andchildren suffered from acute gastrointestinal diseaseresulting from bacterial contamination of stagnantpond water. Consequently, during the 1970s theUnited Nations Children s Fund (UNICEF )workedwith the Department of Public Health Engineering toinstall tube-wells to provide what was presumably asafe source of drinking-water for the wells consist of tubes that are 5 cm in diameterthat are inserted into the ground at depths of usuallyless than 200 m.

6 The tubes are then capped with a cast1 Professor of Epidemiology, 140 Warren Hall, School of Public Health,University of California, Berkeley, Berkeley, CA 94720-7360, USA(email: Correspondence shouldbe addressed to this Research Student, School of Public Health, Universityof California, Berkeley, Fellow, Public Health Sciences Division, InternationalCentre for Diarrheal Disease Research in bangladesh , Dhaka, bangladesh ; Division of Occupational and Environmental Medicine,Faculty of Health Sciences, Linko ping University, of the World Health Organization, 2000,78(9)#World Health Organization 2000iron or steel hand pump. At the time the wells wereinstalled, arsenic was not recognized as a problem inwater supplies, and therefore standard water testingprocedures did not include tests for arsenic (7).)

7 During the 1980s, UNICEF s support forinstalling tube-wells decreased because the privatesector was able to supply and install millions more ofthem (7). By 1997, UNICEF indicated in its countryreport for bangladesh that it had surpassed its goal ofproviding 80% of the population by 2000 with accessto safe drinking-water in the form of tube-wells,ring-wells and taps (8). Presently, three out of fourtube-wells in bangladesh are privately owned (7).Extent of exposure in the populationIn bangladesh , arsenic contamination of water intube-wells was confirmed in 1993 in the Nawabganjdistrict (1). Further testing was done in the followingyears; this included investigations by the Departmentof Occupational and Environmental Health of theNational Institute of Preventive and Social from various laboratories were collated in aWHO country situation report in 1996 (9).

8 Theinstitutions that provided results included theJadavpur University in Calcutta, India, the Bangla-desh Atomic Energy Commission, the Departmentof Public Health Engineering s laboratories in theKhulna and Rajshahi districts, and the NationalInstitute of Preventive and Social Medicine in , 400 measurements were presented in thereport, although contamination in some wells wasmeasured by more than one laboratory. In about halfof the measurements concentrations were above50mg/l (9), which is clearly in excess of themaximum level recommended by WHO of 10mg/l(10 )and greater than the maximum level of 50mg/lpermitted in bangladesh (7).To raise awareness of the seriousness of thearsenic problem in West Bengal and to draw attentionto the need for studies in bangladesh , a conferencewas convened in 1995 by D.

9 Chakraborti and theSchool of Environmental Studies of JadavpurUniversity in Calcutta (11). In the years after theconference, the extent of the problem in Bangladeshhas become clearer through additional surveys of thewater and population, many of which were led study conducted in the Rajarampur village ofthe Nawabganj district, by the National Institute ofPreventive and Social Medicine and the School ofEnvironmental Studies, found that 29% of the294 tube-wells tested had arsenic concentrationsgreater than 50mg/l (12). Between September 1996and June 1997, a survey was jointly conducted byDhaka Community Hospital and the School ofEnvironmental Studies. An examination of 265 wellsin Samta village in the Jessore district found thatabout 91% of the wells had arsenic concentrationshigher than 50mg/l (13).

10 In 1998, a British GeologicalSurvey of 41 districts collected 2022 water samples 35% were found to have arsenic concentrationsabove 50mg/l (Table 1 )and were above300mg/l (14). Based on population density mea-sured in 1998, this group estimated that the numberof people exposed to arsenic concentrations above50mg/l was about 21 million. This number would beapproximately doubled if WHO s standard of 10mg/lwere adopted. Further studies conducted by theTable of groundwaters surveyed in 1998 by theBritish Geological Survey with arsenic levels over 50mg/lDistrict% ofDistrict% ofgroundwatersgroundwaterssurveyedsurvey edBagerhat66 Madaripur93 Barisal63 Magura19 Brahmanbaria38 Manikganj15 Chandpur96 Meherpur60 Chittagong20 Moulvibazar12 Chuadanga44 Munshiganj83 Comilla65 Narail43 Cox s Bazar3 Narayanganj24 Dhaka37 Nawabganj4 Faridpur66 Noakhali75 Feni39 Pabna17 Gopalganj94 Pirojpur24 Jessore51 Rajbari24 Jhalakati14 Rajshashi6 Jhenaidah26 Satkhira73 Khulna32 Shariatpur80 Kushtia28 Sylhet19 Lakshmipur681094 Bulletin of the World Health Organization, 2000,78(9)


Related search queries