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Genetic study of high background radiation regions/India

Nuclear Monitor Issue: 

(April 27, 1990) The US National Academy of Sciences recently revised the risk estimate for radiation induced cancer which is now 10 to 14 times higher than their 1980 estimate (see WISE News Communique 326/7.3261). The new estimate is based on recent reanalysis of data on bomb survivors and the studies of medically irradiated persons conducted by Dr. Alice Stewart and others.

(331.3311) WISE Amsterdam - However, as members of the Centre for Industrial Safety and Environmental Concerns in India point out, the estimate of radiation induced genetic and congenital anomalies is still based on extrapolation of findings among animals. The gross underestimation in this area still continues. "What," they ask, "will be the effect of an increase in radiation exposure due to nuclear power and other human-made sources on the health and well being of future generations? How many more unfinished children (known as Downs syndrome caused due to an extra two chromosomes) will be born if Kaiga and Koodamkulan (nuclear plants being built in India) start functioning?"

The center says a near accurate answer to that question would already be available had the nuclear research establishment conducted a recommended detailed health study among the people living in higher natural background radiation regions (HBRRs) in Kerala and Tamil Nadu, India. Due to the presence of thorium and uranium, the background radiation in the fishing villages of Neendakara, Chavara, Ponmana and Alappat in Kollam and all the coastal villages in the Kanyakumari district is very high. People have been living in these HBRRs for several generations. Considering the uniqueness of these people, the World Health Organization had, in 1957, recommended that such a study be conducted there. However, the nuclear energy researth establishment instead went to the extent of preventing or dissuading researchers from civil medical research establishments such as the All India Institute of Medical Sciences and the Medical College Trivandrum from conducting it. So, now, the center has taken on the task.

So far, the center has completed a survey in the Kerala and Tamil Nadu HBRRs, details of which are summarized below:

  1. Collection of socio-economic and demographic information from 6500 households from Kerala HBRR and 5500 households from a comparable control area in Alleppey district.
  2. Detailed clinical examination and review by specialists of all diseases suspected to be of genetic or congenital origin.
  3. Copying of parish registers for baptism, burial and marriage for the past 100 years from 30 parishes in coastal Alleppey, Quilon and Kanyakumari districts.
  4. Collection of birth and deaths from local government offices in Quilon and Alleppey for the past 10 years.
  5. Details of disabled students in the above districts examined by a government medical board for the past three academic years.
  6. Clinical records of 16,000 cancer patients from hospitals in Kanyakumari district.
  7. A study of chewing, drinking and smoking habits of a sample cancer patients in the KK district.
  8. Chromosome study of 100 normal and mentally retarded persons conducted at a national laboratory.
  9. Measurement of gamma activity at more than 700 locations, indoor radon concentration in 12 houses and analysis of fish samples f or radionuclide concentration. The radon study has been done by a lab in the US while the fish studies are being conducted in a European lab.

Between 18 and 25 February of this year the center's international advisory board met and discussed the findings. The preliminary results show that the prevalence of Down's syndrome in the radiation exposed population is three times higher than that of the control population. There is a significant deviation from an earlier study showing no cases of Down's syndrome in the control area (population 6,000). There was a statistically significant difference In the prevalence of mental retardation, epilepsy, cleft lip and palate, etc. A few extremely rare genetic disorders have also been observed. A further disturbing finding is the higher number of childless couples in the HBRR.

The advisory board meeting, chaired by Dr. Rosalie Bertell of the International Institute of Concern for Public Health in Canada, decided to do a finer analysis of over 96,000 pregnancies of 18,000 mothers from both the regions. The parish data needs also to be analyzed to see if there is any difference In sex ratio at birth and sex-wise age at death in the study and control population. These should be completed during the next few months. In the meantime, the preliminary findings are available from the address below.

Source and contact: V.T. Padmanabhan, Centre for Industrial Safety and Environmental Concerns, Kottamukku, Quilon, Pin: 691 013, India, tel: 0474-2765.