环境化学是研究化学物质在环境中迁移、转化、降解规律，研究化学物质在环境中的作用的学科。它不应与绿色化学，即探求如何减少潜在的污染源头的学科搞混乱。它可以定义为研究源头、反应、物质运动、作用效果、以及化学元素在空气、土壤和水利环境的生存和人类活动对其的影响。 环境化学是在各个学科之间的科学，包括大气、水生以及土壤化学，也减轻在分析化学和使环境与其他有关科学的部分发生关系起到很大作用。 环境化学重要的研究成果是发现滴滴涕在环境中很难降解，并会在通过食物链在动物体内蓄积，导致在全世界禁止生产、使用滴滴涕；另外发现氟里昂在环境中不降解，会消耗、破坏臭氧层，导致对氟里昂使用、生产的限制和无氟冰箱的出现，

Environmental chemistry is the scientific study of the chemical and biochemical phenomena that occur in natural places. It should not be confused with green chemistry, which seeks to reduce potential pollution at its source. It can be defined as the study of the sources, reactions, transport, effects, and fates of chemical species in the air, soil, and water environments; and the effect of human activity and biological activity on these. Environmental chemistry is an interdisciplinary science that includes atmospheric, aquatic and soil chemistry, as well as heavily relying on analytical chemistry and being related to environmental and other areas of science.