35 years later, Bhopal gas leak failures resurface in Vizag
As I see images of the Vizag gas leak from the LG plant and hear of the deaths and injured people, it is an eerie flashback to the time I visited Bhopal in 1985 a few weeks after the toxic gas leaked from the Union Carbide plant in December 1984. I was shocked to see the number of people sick and dying in the Bhopal hospitals.
In both cases, the accident happened at night and the gas plume escaping from the plant affected the nearby community. Both plants were resuming production after a period of downtime, and it is clear that errors occurred in the protocols.
As it turned out, the methyl isocyanate gas from the Union Carbide plant was more toxic than the styrene that leaked from the LG plant. However, the 11 deaths so far and hundreds of affected people in hospital indicate that styrene must have escaped in extremely high concentrations and affected the nearby population.
Styrene is a chemical used in plastic and rubber manufacturing, and is toxic to the brain and lungs. The permissible exposure level (PEL) mandated by the US Occupational Safety and Health Administration (OSHA) is 100 ppm (parts per million) for an adult worker for eight hours and the Immediately Dangerous to Life and Health level is 700 ppm. This level has been severely exceeded, indicated by the number of deaths and injured.
The health effects of styrene on the lung include irritation of the eyes, nose, and throat, cough, shortness of breath, chemical inflammation of the lung tissues, and possible accumulation of fluid which can lead to death, a condition known as pulmonary edema. Brain effects include a feeling of drunkenness, changes in colour vision, tiredness, confusion, slowed reaction time, concentration and balance problems.
The International Agency for Research on Cancer (IARC) has classified styrene as a possible carcinogen. There is no known antidote to this toxin so aggressive supportive management and treatment is the need of the hour. The supportive treatment is typically washing skin to remove the chemical, administration of oxygen, and symptomatic treatment.
The questions that need to be answered immediately are: How much of the toxin escaped into the environment? What were the emission levels downwind of the plant? Are there other toxins that also escaped? What is the area of spread of the gas? Which neighborhoods are affected, Did the toxin seep into the soil and water? And how many people were at risk of exposure to this toxic gas cloud?
Some of these questions can be answered by urgently modelling the gas plume dispersion.
Note that the PEL of 100 ppm is for a healthy adult worker but the exposed population in Vizag would certainly comprise children, pregnant women, older individuals, and people with heart, lung, and other disabilities which would render them more vulnerable to the toxic effects of styrene. In addition, in people with Covid-19 infection, the inflammatory effects of styrene could be far worse.
Concurrent with the immediate treatment, a search must be made for the population potentially exposed to styrene, so that they may be monitored in the immediate aftermath, as well as in the medium and long term.
Thirty six years after the Bhopal disaster, it is distressing to see accidents from hazardous industries. The fields of occupational and environmental medicine, toxicology, and epidemiology which study and prevent industrial accidents have still not been developed adequately to cater for the amount of industrial development that has occurred in India. After the Bhopal disaster, I was frustrated that this field was not available in India and I had to go overseas to study these subjects. In 2020, I’m not sure very much has changed.
(The writer is a specialist in occupational and environmental medicine and is a member of the International Medical Commission on Bhopal. He teaches at the Indian Institute of Public Health in Hyderabad).