Arsenic Affects the Whole Body
Report on Medical Survey in West Bengal, India
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Arsenic affects the whole body An Asia Arsenic Network (AAN) survey team visited the State of West Bengal, India, and Bangladesh, from February 5 through 12, 1996, and carried out medical and environmental surveys in the arsenic affected areas in the two countries.
Arsenic contamination in underground water on the eastern side of the River Hooghly, a branch of the River Ganges, in West Bengal, has been reported since 1978. The first group of patients suffering from arsenic poisoning was found in July, 1983, and since then the af-fected area has been expanding with an ever increasing number of new patients. In particu-lar, since 1988, it has been clear that there are contaminated areas in the six districts of West Bengal; namely, Malda, Murshidabad, Nadia, Burdwan, North 24-Parganas and South 24- Parganas. The area affected covers 3,400 Km2 with a population of approximately 30 mil-lion. The number of people who are using water from arsenic-contaminated tubewells (highest concentration 3.7 ppm) in these areas exceeds one million, among whom 200,000 people were confirmed to have skin lesions characteristic to arsenic poisoning. This is al-ready the largest arsenic poisoning in history to have happened in one area. However, the spread of arsenic contamination has been confirmed in the Ganges delta of Bangladesh, the country neighbouring West Bengal.
The AAN sent three representatives to the "International Conference on Arsenic in Ground Water: Cause, Effect and Remedy" held at Jadavpur University, Calcutta, in February, 1995. According to the suggestion by those representatives, the AAN carried out field sur-veys on this visit to observe the realities of arsenic contamination and to collect information and materials that could assist the finding of solutions. The team visited nine villages in the District of North 24-Parganas, where those residents who drink water from arsenic- contami-nated tubewells gathered and we carried out dermatological, internal, neurological and psychiatric examinations.
Affected after 6-month of drinking
The subjects were examined in a crowd outdoors. Hence, it was not possible to make full records of the epidemiological background of each one. However, of the 169 residents (97 male and 72 female), our records covered the period of drinking tubewell water among the following occupational groups: agriculture 41, housewives 41, manufacturing 6, craftsmen 5, trading 5, students 5, domestic helpers 2, unemployed 2 and others 3.
The period of drinking tubewell water varied from four months to 45 years, with the largest group of 63 for 6-10 years (see Table 1):
Table 1: Period of drinking tubewell water
Less than 1 year 1 1 - 5 years 8 6 - 10 years 63 11 - 15 years 20 16 - 20 years 34 21 - 25 years 7 26 - 30 years 8 Over 30 years 7 148 People
According to the surveys made in the seven districts of West Bengal during 1983 and 1987 by Dr. K. C. Saha (Professor of Dermatology, retired, School of Tropical Medicine, Calcutta), who found the first group suffering from arsenic poisoning in July 1983, the mean level of arsenic concentration in tubewell water was 0.32 ppm (0.06-1.25) and the time lag for the appearance of arsenical symptoms after drinking contaminated water varied between six months and 2 years.
Our survey examined neither the concentration levels nor the date of original arsenic contamination of tubewells. However, it may be reasonably inferred from Dr. Saha's reports that the contamination began in the seven districts of West Bengal around 1980-81. Therefore, it is unlikely that there would be an unduly large error in estimating the longest period of exposure to arsenic of residents in West Bengal in 1996 to be 16 years.
Many diffused hyper-pigmentation cases observed
Hyperpigmentation on the mucosa as well as diffused pigmentation on the trunk and palm is, symptomatologically, one of the characteristic signs of arsenic poisoning in West Bengal.
Of the 167 people on whom the AAN survey team were able to conduct skin examinations, 163 (97.6%; 3-80 years of age) were found to have skin lesions related to arsenic, as shown in Table 2.
Table 2: Dermatological Findings
Hyperpigmentation Trunk Diffused 160 (95.8%) Spotty 114 (68.3%) Palm Diffused 127 (76.0%) Spotty 71 (42.4%) Sole Diffused 4 ( 2.4%) Spotty 15 ( 9.0%) Mucosa Bucca 27 (16.2%) Lip 26 (15.6%) Tongue 21 (12.6%) Gingiva 32 (19.2%) Palate 2 ( 1.2%) Depigmentation: 68 (40.7%) Hyperkeratosis: Palm Diffused 33 (19.8%) Spotty 84 (50.3%) Sole Diffused 142 (85.0%) Spotty 108 (64.7%) Dorsal hand and foot ( 0.6%) Tumor: Bowen's disease 3 ( 1.8%) SCC* 2 ( 1.2%) BCC** 1 ( 0.6%) Non-diagnosed 1 ( 0.6%) Others: Leg edema 1 ( 0.6%) Ichtyosis 5 ( 3.0%) Dupuytren's contracture 1 ( 0.6%)
*)=Squamous cell carcinoma
**)=Basal cell carcinoma
Increase of skin cancer is feared
With regard to skin tumors, Dr. Saha found six cases (0.5%) of SCC (squamous cell carcino-ma) among 1214 people he examined during 1983-87, but he did not observe any other ma-lignant neoplasms like Bowen's disease. Our survey, however, found three cases of Bowen's disease, two SCC's, one BCC and another undiagnosed case; altogether seven cases (4.29%) of malignant skin tumor.
One of the reasons for the small number of cases of skin tumor in Dr. Saha's reports is pro-bably that his surveys were made after only a relatively short period of exposure to arsenic.
Our medical examination was carried out more than 10 years after his last survey, and even after taking account of the latency period of skin cancer due to chronic arsenic poisoning, it is feared that the number of skin cancer patients will increase in future among the exposed resi-dents. It is therefore of vital importance to monitor the health conditions of residents in this area.
Hepatomegaly as a characteristic sign
The number of residents examined for clinical manifestations excluding the skin was 153 (86 male and 67 female), and the ages ranged from 3 to 80 years. Details are given in Table 3.
Dr. D. N. Guha Mazumder, Professor and Head of Department of Gastroenterology, Institute of Post Graduate Medical Education & Research in Calcutta, reports many cases of hepato-megaly, splenomegaly and non-cirrhotic portal fibrosis (NCPF). The reason why those three diseases appear at a higher rate in West Bengal than other cases of arsenic poisoning elsewhere is unknown, but many patients of hepatomegaly were found in our survey, too.
Disturbances of respiratory and digestive systems are often observed as the first sym-ptoms of chronic arsenic poisoning caused through drinking water contaminated at this level (2 ppm).
Neither Dr. K. C. Saha nor Dr. D. N. Guha Mazumder mention cases of disturbances of the circulatory system. Such disturbances mainly appear at later stages of arsenic poisoning as an arteriosclerotic change. It is not clear how much arsenic has acted on the circulatory distur-bances observed in our survey. However, it is recorded here as one of the symptoms found among the arsenic-affected residents in West Bengal.
Polyneuropathy, a peripheral neuro-logical disturbance, is often found among patients with arsenic poisoning, but only 3 cases, all at light levels, were found during our survey.
Table 3: Clinical manifestations except skin
Disturbance of respiratory system including bronchitis: 39 (25.4%) Hepatomegaly: 27 (17.6%) Disturbance of digestive system: 22 (14.3%) Disturbance of circulatory system: 16 (10.4%) Heart disturbances 10 (6.5%) Cerebral infarction 3 (1.9%) Gangrene in the extremities 3 (1.9%) Neurological symptoms: 37 (24.1%) Superficial sensory disturbances 17 (11.1%) Hyporeflexia and areflexia 16 (10.4%) Polyneuropathy 3 (1.9%) Auditory disturbances 8 (5.2%) Muscular atrophy 5 (3.2%) Psychiatric symptoms: 14 (9.1%) Depressive state & hypochondria 10 (6.5%) Apathy 2 (1.3%) Dementia 2 (1.3%)
Check on internal cancers is necessary
Generally speaking, arsenical cancers appear, symptomatologically, first on the skin followed by cancers on the internal organs. There have been no reports of internal cancers so far in cases of arsenic poisoning in West Bengal. It could be because the West Bengal cases have not passed latency periods for internal cancers.
Suppose the arsenic contamination began 16 years ago in 1980. It may then be inferred that it would take some further years for internal cancers, such as lung cancer, to appear. However, as reported above, there are unmistakable signs of the occurrence of skin cancer. What is required therefore, is a systematic examination for internal cancers at the time of medical check-ups of the residents in arsenic affected areas in the future.
Due to in-stability associated with the general election, our activities in Bangladesh from February 9, 1996, were limited to a meeting with the Bangladesh Arsenic Committee and a visit to Nara-yanganji in the suburbs of Dhaka.
On Friday, February 10, members of the Arsenic Committee and officers of the Narayanganji Public Health Office guided us to the New Palpara District. We were informed that in 1995 an arsenic concentration of 1.0 ppm had been found in tubewell water there, and that skin lesions of chronic arsenic poisoning were observed on five people including the family using the tubewell. A tubewell water analysis, using a simplified method of arsenic measurement, found concentrations of arsenic ranging from 0.2 ppm to 0.5 ppm, far above the permissible standard set by WHO, among 5 of the 17 samples examined.
It is clear therefore that thorough surveys are required in Bangladesh.
Dr. Masazumi Harada and Ms. Pranati Sarkar at PG Hospital, Calcutta (February 9, 1996). Pranati died of kidney cancer on April 26 at the age of 32.
The survey team consisted of Nobuyuki Hotta* (presently a psychiatrist at Sakuragaoka Hospital, Kumamoto), Masazumi Harada (Associated Professor, Kumamoto University School of Medicine), Yasuko Kojo (Head of Dermatology Division, Kumamoto Central Hospital), Hiroshi Yokota* (Professor, Faculty of Engineering, Miyazaki University), Hiromi Hironaka* (analytical chemist; Environmental Inspector for Hakata Public Health Office, Fukuoka), Shoko Oshikawa (pharmacist), and Sachie Tsushima (Director - International Re-lations, AAN). [Those with an asterisk (*) also visited Bangladesh.]