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.
Botanist
cosmologists
seismologist
a biologist
Mathmaticion