Environmental Toxicology, Bachelor of Science College of Agricultural & Environmental Sciences

Toxic agents in the environment include pesticides, food additives, industrial waste, and metals as well as chemicals produced by animals, plants, fungi and bacteria. Students in the Environmental Toxicology major learn how toxicants produce adverse effects by understanding their environmental fates and biological activities. They learn about monitoring concentrations and the distribution and persistence of agents found in water, soil, air and foods. Toxicity testing procedures and exposure assessments are used to help evaluate the potential for harm to humans and other species. By understanding the cellular targets and biochemical mechanisms of perturbation by toxicants, toxicologists can better estimate adverse effects. Overall, students learn mechanisms by which toxic agents act, their origin and fate and how toxicologists evaluate the risk of adverse effects and balance them against the benefits.

The Program

Preparatory courses in biology, chemistry, mathematics, and physics are required to provide fundamental principles that underlie toxicology. Students in the major are expected to understand the environmental fates and biological activities of different classes of toxic substances, and the legislative issues that arise from chemical use. Opportunities are available to develop an in-depth understanding in areas of emphasis through a selection of electives.


Elective course work in many disciplines can complement the required core courses. Providing a framework for selecting restricted electives, the major offers specializations in (1) Ecotoxicology & Environmental Chemistry, (2) Forensic Science & Regulatory Toxicology, and (3) Molecular & Biomedical Toxicology. The first category includes topics in chemical fate, transport and degradation, as well as ecology, wildlife, and aquatic toxicology. The second category includes forensic science, environmental policy and management, and public health. The third category includes pharmacology, biotechnology, medicine, veterinary medicine, and food toxicology. Students are encouraged to select course work from these Emphases and beyond to match their interests.

Internships & Career Alternatives

Occupations that use environmental toxicology include risk assessment, pharmaceutical development, food additive toxicity testing, managing regulatory compliance, residue or forensic analysis, pest control, monitoring and field sampling, industrial hygiene, and environmental health and safety. A substantial proportion of graduates elect to pursue advanced professional training in law, medical, pharmacy, or veterinary medical school, or in graduate programs in pharmacology, toxicology, agricultural and environmental chemistry, or public health. During undergraduate study, optional internships or research projects are recommended to provide training and work experience to help students pursue future goals.

Lead Faculty Advisor

Michele La Merrill

Environmental Toxicology Major Advisor

Erica Cefalo

Advising Center for the major is located in 1086 Academic Surge. Contact the Environmental Toxicology major advisor at 530-754-9796.

The major requirements below are in addition to meeting University Degree Requirements & College Degree Requirements; unless otherwise noted. The minimum number of units required for the Environmental Toxicology Bachelor of Science is 118.

Preparatory Subject Matter
Biological Science
BIS 002AIntroduction to Biology: Essentials of Life on Earth5
BIS 002BIntroduction to Biology: Principles of Ecology & Evolution5
BIS 002CIntroduction to Biology: Biodiversity & the Tree of Life5
Choose a series:15
General Chemistry
and General Chemistry
and General Chemistry
Honors General Chemistry
and Honors General Chemistry
and Honors General Chemistry
Chemistry for Life Sciences: Determining Structure & Predicting Properties
and Chemistry for Life Sciences: Predicting & Characterizing Chemical Change
and Chemistry for Life Sciences: Controlling Processes & Synthetic Pathways
Choose CHE 118 series or CHE 128 series & CHE 129A or CHE 103 series:10-12
Organic Chemistry for Health & Life Sciences
and Organic Chemistry for Health & Life Sciences
and Organic Chemistry for Health & Life Sciences
Organic Chemistry
and Organic Chemistry
and Organic Chemistry
and Organic Chemistry Laboratory
Chemistry for Life Sciences: Determining Organic Structures & Properties
and Chemistry for Life Sciences: Predicting & Controlling Organic Pathways
Choose a series:12
Calculus for Biology & Medicine
and Calculus for Biology & Medicine
and Calculus for Biology & Medicine
and Calculus
and Calculus
PHY 007AGeneral Physics4
PHY 007BGeneral Physics4
PHY 007CGeneral Physics4
Choose one:4
Applied Statistics for Biological Sciences
Applied Statistics for Business & Economics
Applied Statistical Methods: Nonparametric Statistics
Applied Statistical Methods: Analysis of Variance
Applied Statistical Methods: Regression Analysis
Upper Division Writing
Choose one: 14
Advanced Composition
Advanced Composition
Advanced Composition
Writing in the Professions: Business Writing
Writing in the Professions: Business Writing
Writing in the Professions: Business Writing
Writing in the Professions: Law
Writing in the Professions: Journalism
Writing in the Professions: Elementary & Secondary Education
Writing in the Professions: Science
Writing in the Professions: Health
Writing in the Professions: Health
Writing in the Professions: Health
Writing in the Professions: Internships
Satisfaction of the General Education requirement to include courses selected with advisor's approval to complement the major; courses in agricultural economics, environmental studies, political science, psychology, and sociology are particularly recommended.
Preparatory Subject Matter Subtotal72-74
Depth Subject Matter
Biological Science
BIS 102Structure & Function of Biomolecules3
BIS 101Genes & Gene Expression3-4
or BIS 103 Bioenergetics & Metabolism
Environmental Toxicology
ETX 101Principles of Environmental Toxicology4
ETX 102AEnvironmental Fate of Toxicants4
ETX 102BQuantitative Analysis of Environmental Toxicants5
ETX 103ABiological Effects of Toxicants4
ETX 103BBiological Effects of Toxicants: Experimental Approaches5
Choose ETX 127 or two others:6-10
Environmental Stress & Development in Marine Organisms
Environmental & Nutritional Factors in Cellular Regulation & Nutritional Toxicants
Perspectives in Aquatic Toxicology
Food Toxicology
Role & Applications of Toxicology in Modern Industry
Environmental Toxicology of Air Pollutants
Health Risk Assessment of Toxicants
Legal Aspects of Environmental Toxicology
Exposure & Dose Assessment
Restricted Electives
Choose three-four courses:12-16
Electives selected for area of Emphasis with faculty advisor's approval with 6 unit combined maximum of 190, 192, 198, and 199; see department website for details.
Depth Subject Matter Subtotal46-55
Total Units118-129

Preferably, the course should be taken prior to enrollment in ETX 102B & ETX 103B.