A rejoinder to the article “Impact of Natural Background Radiation on Health: Understanding the Debate” by T S Krishnan, Annapureddy Rama Papi Reddy and M V Ramana is brought out to ensure that the public at large is provided with a more scientifically correct and balanced perspective. The statement that any expansion of nuclear plants would result in deleterious effects on public health leads to building up an unnecessary and irrational fear of radiation in the minds of the public.
The article “Impact of Natural Background Radiation on Health: Understanding the Debate” (EPW, 12 September 2020) by T S Krishnan, Annapureddy Rama Papi Reddy and M V Ramana has raised a pertinent issue concerning high levels of naturally occurring radiation, such as that in some regions of Kerala, and the observable impact on health, if any. The authors conclude, without any substantiation, “any increase in radiation dose will result in a detrimental impact on the health of exposed populations.” In order to ensure that the public at large is provided with a more scientifically correct and balanced perspective, and an unfounded public fear is not created due to the above statement, the following anomalies in the report are being brought out:
(i) The authors cite the study by Kochupillai et al (1976) that reported an abnormally high incidence of Down’s syndrome in populations residing in the High Natural Background Radiation Areas (HNBRAs) in the coastal regions of Kerala as compared to those in other countries. This study reported a frequency of 0.93 per 1,000 in the study population while zero cases were reported in a control population of 5,938 which was highly underreported. This frequency is similar to any other general population, for
example, 0.83 per 1,000 in New Delhi (Verma et al 1998) and 0.87 per 1,000 in a multicentric study from Mumbai, Delhi and Baroda (Verma et al 2000). Later, Verma et al (1977) agreed that “comparison of the number of cases of Down's syndrome born to women of specified ages with the frequency at birth may not be entirely valid.” Similarly, Padmanabh et al (2004) reported a frequency of 0.64 per 1,000, again not beyond normal for Down’s syndrome, but extremely low frequency of 0.14 per 1,000 in control population. Discounting the data by Kochupillai et al (1976) and a few others, BEIR V report (1990) concludes,
There were no differences for a large number of hereditary diseases or congenital defects in children. The prevalence of Down’s Syndrome was greater in the high-background region, but this was discounted because the residents of the control area had a lower prevalence of Down syndrome than those of surrounding counties, who had rates similar to those living in the high natural background area.
