Environmental chemistry is the study of chemical processes that occur in water, air, terrestrial and living environments, and the effects of human activity on them. It includes topics such as astrochemistry, atmospheric chemistry, environmental modelling, geochemistry, marine chemistry and pollution remediation.Environmental chemistry focuses on the presence and impact of chemicals in soil, surface water, and groundwater. Environmental chemists study how chemicals - usually contaminants - move through the environment. They also study the effects of these contaminants on ecosystems, animals, and human health.