Visakhapatnam gas leak Why in News : The Visakhapatnam gas leak, also referred to as the Vizag gas leak, was an industrial accident that occurred at the LG Polymers chemical plant in the R. R. The gas was confirmed to be styrene or vinyl benzene. The leak reportedly occurred because of overheating, leading to pipe leaks. The impact zone has been in the range of 2-3 kilometres around the company. What is Styrene?  Styrene — an organic compound used in the production of polymers, plastics and resins — is manufactured in petrochemical refineries.  It is a poisonous, inflammable gas.  It is used in the production of polystyrene plastics and resins.  These materials are subsequently used in food packaging, rubber, plastic, insulation, fiberglass, pipes and automobile parts.  It is also known as PVC gas (polyvinyl chloride), as it is used in the production of PVC.  Styrene is the 20th most-used chemical in the world, according to the World Health Organization. Where it can be found? The chemical can be found in air, water and soil once released into the environment. It is broken down in air in 1-2 days, while it evaporates from soil and shallow water surfaces. It is broken down by micro-organisms if it reaches soil. How it affects living beings?  It can enter the human body through breathing, eating food and contact through skin.  Once it enters the human body, styrene takes a few days to break down into other chemicals and pass through urine.  It is the most harmful in its most basic form as a monomer (a single unit of styrene).  When humans are exposed to styrene, it causes eye irritation and gastro-intestinal effects.

 It also impacts the outer layer of tissues in the skin causing erosion and bleeding in the short term.  Long-term effects include central nervous system dysfunction, depression, hearing loss and peripheral neuropathy (a numb feeling in the hands and feet).  It also leads to an increase in the colour confusion index that may lead to colour blindness.  Animal studies show they are more sensitive to styrene exposure and suffer greater effects. The styrene concentrations that cause these effects are more than a thousand times higher than the levels normally found in the environment.  Styrene is a possible carcinogen and can cause cancer under long exposure. How people are treated? The most important immediate treatment is to give oxygen to affected people. The people in the zone also need to be evacuated as long-term exposure can be detrimental to their health. Concerns ahead: Styrene at the levels of 300-375 ppb for a short period can cause neurological disorders and levels less than this can cause other health impacts. It stays in air for weeks and is highly reactive. It can also combine with oxygen to form styrene dioxide which is more lethal. Way ahead: Risks are unavoidable while operating petrochemical units, which is why countries in the European Union are moving towards green approaches such as bioplastics which will reduce the demand for toxic chemicals such as styrene. Research is still underway on biodegradable bioplastics using agricultural wastes, which could replace polystyrene.

Sources: down to earth. https://www.downtoearth.org.in/dte- infographics/vizag_gas_leak/index.html#:~:text=THE%20GAS%20leak%20incident%20at,in%20the%2 0country%20that%20day.&text=The%20result%20was%20leakage%20of,how%20toxic%20it%20is').