Study reveals that oil spills are changing marine DNA

A study by the Goa-based National Institute of Oceanography (NIO) has revealed that snails, oysters and clams affected by toxic oil components, if eaten, can cause cancer in humans.

Published in the Indian Journal of Medical Research in February 2005, the study, ‘Detection of DNA Damage (strand breaks) in marine mollusk: An Early Warning Signal of Carcinogenesis’, is the first of its kind in India.

The study, conducted by the NIO’s Marine Pollution Assessment and Ecotoxicology Group, found that polyhydrocarbon (PAH), a toxic component of crude oil, gasoline and fuel oil, had affected the DNA of marine snails (Cronia contracta) and oysters and clams found near Vasco, Goa. PAH accumulations in humans can cause cancer, the study concludes.

A recent oil spill occurred on the Goa coastline on March 23, 2005, when a Maritime Wisdom oil tank, a Singaporean bulk carrier, collided with Prapti. This led to 110 tonnes of oil spilling across three miles. 

“The immediate effect of an oil spill in the vicinity of its occurrence is enormous, but because of the ocean’s dynamism the concentration reduces substantially in a few days,” says Anupam Sarkar, who led the NIO study. But while the concentration diminishes, the damage spreads.

Several factors govern the damage. Says Sanjiv Gopal, Oceans campaigner, Green Peace, “It depends on the type of oil, the thickness of deposits, climate and season, the area’s physical, biological and ecological characteristics, sensitivity of species and biological communities.”

One reason for cheer, say experts, is that there are fewer incidents of oil spills in India as ship construction safeguards are more stringent. Furthermore, damage to the ecosystem is reduced as volatile compounds tend to evaporate in our warm climate.

Still, the study’s findings are ominous. While you nibble on seemingly harmless snails or oysters at a shack in Goa, it is possible they are causing irrevocable damage to your body.