The city of Bhopal, in Madhya Pradesh, central India, suffered the world’s worst ever industrial disaster in December 1984, when around 500 000 inhabitants were exposed to toxic gas from the Union Carbide India Ltd (UCIL) pesticides factory. Somewhere around 8,000 people died immmediately, with estimates ranging from 3,000 to 20,000. A further 150,000 sustained long-term injuries.
Where as the components of the gas cloud were comparatively short-lived, the factory, now abandoned, remains heavily contaminated with a range of persistent pollutants, both organic and inorganic in nature. Green peace first investigated the contamination in and around the site in 1999, focussing primarily on the contamination of soil and drinking water.
However, there are also significant chemical stock piles housed in several of the buildings of the former factory. They are investigated in this current study, which also updates the status of contamination in the soil of Union Carbide’s former solar evaporation ponds (SEPs), into which process waste waters were discharged over a period of some seven years. Twelve “stockpile” samples were collected from six locations inside the site and four soil samples were collected from the SEPs. The stockpile samples were analysed to determine their content of carbaryl (sevin), the main product manufactured in Bhopal, as well as hexachlorocyclohexane (HCH) isomers that were also used as an insecticide under the common name of BHC, and hexachlorobenzene, one of the known contaminants of BHC. They were also screened to identify as many of the other organic constituents as possible. In addition to the stockpiles that were sampled, dumped materials were noticed at sever allocations and the laboratory building was found to contain many bottles of unused reagents. The soil samples from the SEPs were screened for organic contaminants and concentrations of heavy metals were determined.
Eleven of the twelve stockpile samples were found to contain carbaryl at concentrations in the low part per billion range. Ten contained hexachlorocyclohexanes, with total concentrations varying between tens of parts per million and almost 10%. HCB was detected in five samples and quantified in three. Concentrations ranged from 580 to 5,800 parts per billion.