The four major areas that are emphasized in Mercer’s graduate Environmental Systems program are epidemiology and toxicology, water quality issues, solid and hazardous wastes, and air quality. The program is open to a broad range of applicants including those that hold a Bachelors of Science in Biology, Chemistry, and Environmental Science, etc. Students who do not have an adequate background in biology, calculus, or chemistry may be required to take additional courses. The Master’s degree program in Environmental Systems requires a minimum of 30 credit hours with a minimum of 18 hours in major.