An ecologist studies pollution
An environmental scientist or an environmental chemist typically studies pollution, its effects on the environment, and methods to mitigate its impact. They may specialize in air, water, soil, or marine pollution.
A mineralogist studies minerals.
There are several scientific field dealing with pollution. Some of them are:EcologyEngineeringBiologyAgricultureMeteorologyMedicineHydrologyForestryEnvironmental studiesIndustrial Hygiene
The kind of scientist who studies Urology would be a Biologist, since Urology concerns a biological function (urination). If you mean the kind of doctor who studies Urology, that would be a Urologist.
meteoroligists
Audiologist
An Ichthyologist.
A zoologist.
Botanist
seismologist
a biologist
cosmologists