Passage Summary: A Canadian lake is full of a pesticide that hasn't been allowed in North America for decades and is rarely used elsewhere.

Reasoning: No reasoning (Fact Set).

Analysis: This paradox presents a local presence of a substance despite a long-standing regional ban and limited global use. To resolve this, we need a mechanism that explains how the pesticide is reaching Lake Laberge specifically. Look for an answer that provides a transport method, such as atmospheric currents or water runoff, that could carry the chemical from the few places it is still used.