by Tanavi Kampli –
Chernobyl is classed as one of the worst nuclear explosions in history [1]. In 1986, the Chernobyl 4 reactor exploded due to inadequately trained personnel. This has caused catastrophic impacts on people’s health which can still be seen today [2].
A review by Cardis E. et al (2006) focuses on the global environmental challenge of human health and contamination by delving deeper into the health implications caused by the Chernobyl accident [3]. They examined 5.2 million people in an ecological study across Belarus, Ukraine and Russia, studying the change in incidence of thyroid cancer and leukaemia [3]. This is essential to planning purposes related to public health, as similar accidents could happen in the future.
Liquidators wearing protective suits while cleaning an area affected by the blast. Source: IAEA Imagebank, CC BY-SA 2.0 via Wikimedia Commons
The incidence of thyroid cancer saw significant increase after the explosion, due to the ingestion of contaminated milk containing high levels of 131I [3]. Controlled case studies carried out by Cadis et al of the young population in Belarus revealed that the risk of thyroid cancer increased by 4.5-7.4, depending on the dose received. This study emphasises the importance of taking good measures during health procedures by showing the implications of being exposed to 131I in childhood [4].
The younger population was more affected by thyroid cancer than adults due to encountering a higher dose of radioactive isotopes via ingestion of milk. The incidence for adults increased after 1995 as the younger population became older, therefore decreasing incidence in children [3]. Studies for adults are inadequate, making the results unreliable. Cases are expected to rise in the future, meaning the extra pressure this will put on health care needs to be carefully estimated, to ensure resources are available to help the population [3].
Effects of radiation exposure contrasted between population groups. 600 000 liquidators (clean-up workers), working in 30km radius of the explosion, were the most affected as they were exposed to the most radiation [3]. They received a mean effective dose of 100mSv, significantly higher than average background radiation [3]. Liquidators had twice as high of a risk of getting cancer [5]. Evacuated inhabitants received a smaller dosage of 33mSv compared to inhabitants who chose to remain in contaminated areas [3]. It is necessary to understand the extent of side effects to being exposed to radiation, so we are able to deal with radioactive waste more effectively.
A controlled case study identifies a link between the risk of leukaemia and radiation dose to the bone marrow [6]. However, there is no significant evidence to suggest Chernobyl increased the incidence of leukaemia due to problems associated with methodology [3]. Data from the Japanese nuclear accident suggests that effects of radiation might not be apparent for decades, highlighting the importance of scientific research in this area and its contribution in improving cancer diagnosis [7].
These studies have clearly showed that Chernobyl has left disastrous, long-lasting health impacts on the population but there are still many unknowns – are there any other undiscovered health impacts? Only time will tell.
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References
[1]: World Nuclear Association (2019) Safety of Nuclear Power Reactors. Available at: https://www.world-nuclear.org/information-library/safety-and-security/safety-of-plants/safety-of-nuclear-power-reactors.aspx [Accessed 3 December 2020]
[2]: World Nuclear Association (2020) Chernobyl Accident 1986. Available at: https://www.world-nuclear.org/information-library/safety-and-security/safety-of-plants/chernobyl-accident.aspx [Accessed 3 December 2020]
[3]: Cardis, E. et al. (2006) Cancer consequences of the Chernobyl accident: 20 years on. Journal of Radiological Protection 26, 127, DOI:10.1088/0952-4746/26/2/001.
[4]: Cardis E. et al. (2005) Risk of thyroid cancer after exposure to 131I in childhood. Journal of the National Cancer Institute 97(10), DOI: 10.1093/jnci/dji129
[5]: Kesminiene A. et al. (2008) Risk of Haematological Malignancies among Chernobyl liquidators. Radiet. Res.170(6) 721-735. DOI:10.1667/RR1231.1
[6]: Davis S. et al. (2006) Childhood leukaemia in Belarus, Russia, and Ukraine following the Chernobyl power station accident: results from an international collaborative population-based case–control study. International Journal of Epidemiology. 35(2) 386-396, DOI:10.1093/ije/dyi220
[7]: Baverstock K., Williams D. (2006) The Chernobyl Accident 20 Years On: An Assessment of the Health Consequences and the International Response. Environmental Health Perspectives. 114(9) 1312-1317, DOI: 10.1289/ehp.9113
[8]: McLaughlin D. (2019) Chernobyl: The lies, the heroes, the horrors. Available at: https://www.irishtimes.com/culture/tv-radio-web/chernobyl-the-lies-the-heroes-the-horrors-1.3878468 [Accessed 3 December 2020]
