Toxicity moves from mercury as chemical toxicant affecting nervous system of humans to the toxicity of (implicit) waves of colonization/imperialism with their imported gendered systems of manliness and capitalist extraction. The matador-bull fight art form/ritual is juxtaposed in the essay, implicitly, to the art form (center of gratuitous expenditure) that is (Swiss designed) remediation science.
the center of a chromatogram (if that's the right word for this) is where a sample is first placed but it becomes a blank spot as it is drawn out radially. toxicity only becomes visible or evident in its downstream, down-time after effects.