Answer
No. Pollutants are substances that harm the environment and eventually makes it unsuitable for living organisms. Thus, when an ecosystem is highly polluted, only those species who were able to evolve and adapt to unfavorable conditions will survive.
Our species may not be considered keystone species. Being on top of the food chain does not equate to saying that our existence significantly affects those of other species. Life on Earth existed even without humans. In any case, the absence of human beings would mean that the natural way by which the ecosystems function would resume.
Work Step by Step
No. Pollutants are substances that harm the environment and eventually makes it unsuitable for living organisms. Thus, when an ecosystem is highly polluted, only those species who were able to evolve and adapt to unfavorable conditions will survive.
Our species may not be considered keystone species. Being on top of the food chain does not equate to saying that our existence significantly affects those of other species. Life on Earth existed even without humans. In any case, the absence of human beings would mean that the natural way by which the ecosystems function would resume.