Question

A gold mine is located beside a river that is a source of food for a nearby village. Miners extract gold from the ore through the process of mercury amalgamation, in which crushed ore is mixed with mercury. The mercury bonds with the gold and draws it out of the surrounding waste, which is then disposed of in tailings ponds located between the mine and the river. Which of the following health risks does the mine most likely pose to the nearby villagers who eat fish from the river?
I.Stomach tumors resulting from acid mine drainage

II. Brain damage resulting from the bioaccumulation of heavy metals

III. Kidney and liver diseases resulting from groundwater contamination

A. I only

B. II only

C. III only

D. I and II only

E. II and III only

Answer 1

Answer:

B. II only. Brain damage resulting from the bioaccumulation of heavy metals.

Explanation:

The mercury concentrated mine tailings dumped in the nearby water bodies undergo methylation process and is converted to methyl mercury by bacteria in the aquatic environment. The aquatic plants absorb this and when fishes eat these plants, they also get contaminated with mercury. This leads to bioaccumulation of mercury in the aquatic environment.  

Mercury is a neurotoxin and contamination in humans by consuming mercury-contaminated fishes leads to neurological damage like memory impairment, decreased concentration and IQ, decreased motor skills or dexterity, tremors, movement disorders, depression, anxiety, or psychosis. Chronic mercury contamination can lead to neurological disorders like Alzheimer’s, autism, Parkinson’s etc.