Pollution is usually defined as contamination that has crossed a set threshold, matter out of place in harmful amounts. The idea that nature has a 'carrying capacity' that can safely absorb waste up to a limit is itself an assumption. It treats the environment as a cargo hold, a container regulators can permit industry to fill.
Pollution doesn't begin in a factory. It begins with the prior assumption that land and water are available for someone else's purposes: as a source of raw materials, a site for plants, and a place to store waste. Pollution is that assumed access put into practice, not a technical malfunction or simply a side effect of profit-seeking.
Colonialism is not only bad actions or bad intentions. It is a set of relations that makes harmful uses of land seem normal and sensible. Environmental research and activism aimed at helping can still rest on those same assumptions of access to land, however well-meaning the people doing it.
Every research method either aligns with or works against colonial relations, because methods are ways of being in the world, not neutral tools. Doing science differently is not an ethical add-on. It reorganizes knowledge, obligation, consent and responsibility, and such science is already being practiced.
When only scientists are allowed to define harm, anything their instruments and methods can't detect gets dismissed. What science measures, or fails to measure, shapes what regulators recognize as pollution and what they bureaucratically allow.