Humans have tripled mercury levels in upper ocean XL Label

Inflectionals

Humans have tripled mercury levels in upper ocean, Industrial Revolution, heavy metal, marine water, mercury, mercury levels in the upper ocean

Same spelling in use by the following Labels:

Increased mercury in Swedish rivers, Batteries, New environmental convention to limit mercury emissions worldwide, Global mercury ban, Minamata Convention Agreed by Nations, Minamata Convention on Mercury to enter into force