Chernobyl is the worst industrial disaster of the 20th century

False !

In brief

Chernobyl (1986) was the worst civilian nuclear accident. 2 workers died immediately, 28 of the 134 workers who received extreme doses died within one year, and another 50 have died since. WHO calculates a few thousand potential deaths among the most at-risk populations. But the worst industrial disaster of the twentieth century remains the Bhopal chemical accident in India (1984), with 5,000 - 25,000 dead and 200,000 - 800,000 injured.

In detail

The comparison should distinguish between immediate deaths, short-term attributed deaths, long-term projections, and total number of people affected. In Chernobyl, UNSCEAR recorded 2 immediate deaths and 134 cases of acute radiation syndrome, with 28 deaths in 1986 among these 134 people [1]. In 2005, WHO reported that fewer than 50 deaths were then directly attributed to radiation, while retaining up to 4,000 possible additional deaths among the most exposed groups [4]. UNSCEAR also reported more than 6,000 thyroid cancers observed in people exposed in childhood or adolescence, including 15 deaths by that time [1].

In Bhopal, WHO counted at least 3,800 immediate deaths due to the explosion of a pesticide plant [4]. The ILO indicates that more than 500,000 people were exposed to the toxic gas [2]. The cumulative assessments then vary according to the sources and the date chosen: the ARIA database (French Ministry of the Environment) recalls an initial official assessment of 1,754 deaths and 170,000 intoxicated, then mentions 3,350 deaths in 1989, 16,000 in 1998, and, in a subsequent summary, a range from 5,000 to 25,000 deaths and 200,000 to 800,000 injured depending on the sources [3].

Chernobyl remains the most serious civilian nuclear accident [1]. But as soon as we compare the impact on human life, Bhopal is much higher by orders of magnitude: the few dozen deaths directly attributed to the radiation of Chernobyl and a few thousand deaths projected, at most, for the most exposed populations [1] [4] must be compared to the thousands of immediate deaths and hundreds of thousands of victims in Bhopal [2] [3].

Sources:

[1] UNSCEAR, The Chernobyl Accident.

[2] ILO, Introduction to chemical safety in the world of work.

[3] ARIA Base, French Ministry of Ecological Transition. https://www.aria.developpement-durable.gouv.fr/wp-content/files_mf/FD7022bhopal_India_10042014_GB.pdf

[4] WHO, Chernobyl: the true scale of the accident.

Illustration: https://www.lemonde.fr/europe/article/2011/04/19/vingt-cinq-ans-apres-la-communaute-internationale-au-chevet-de-tchernobyl_1509685_3214.html