Polyaromatic hydrocarbons (PAHs)

Polyaromatic hydrocarbons (PAHs)

Why it matters? 

  • Following the ELSA 3 shipwreck in the Arabian Sea, a scientific investigation by the Centre for Marine Living Resources and Ecology (CMLRE) confirmed significant ecological disruption from leaked furnace oil and diesel.  

  • The study detected elevated levels of PAHs like naphthalene and fluorene in the water, which have bioaccumulated in the marine food chain. 

  • Asia contributes ~55% of global PAH emissions, with China and India as top emitters. 

What you should know? 

  • PAHs are a group of chemical compounds generated from the incomplete combustion of organic materials like coal, oil, gas, and wood.  

  • Other PAH Compound includes: Anthracene, phenanthrene, fluoranthene, and pyrene. 

  • They are ubiquitous contaminants found in air, water, and soil, and can exist in both gas and particulate phases.  

  • Benzo[a]pyrene (B[a]P) is often used as a key indicator for the entire PAH family. 

Hydrocarbon-degrading bacteria 

  • Hydrocarbon-degrading bacteria such as Neptunomonas acidivorans, Halomonas tabrizica, and Acinetobacter baumannii.  

  • Their abundance at the spill site points to natural bioremediation potential. 

Sources: 

  • Anthropogenic sources  

  • biofuel combustion, motor vehicles, industrial processes (coal coking, petroleum refining, aluminium production, etc.), residential heating, tobacco smoke. 

  • Other major sources  

  • These include industrial processes, motor vehicle traffic, residential heating, and waste incineration. 

  • Natural sources  

  • Include forest fires and volcanic eruptions. 

Health and Environmental Impacts: 

  • Many PAHs are carcinogenic.  

  • PAHs can bioaccumulate in the food chain.  

  • For example, zooplankton can absorb PAHs, which are then transferred up the food web to fish and potentially humans

  • Exposure linked to lung cancer, even in non-smokers.  

  • Other risks: DNA damage, genetic mutations, and oxidative stress.