This doctoral-level course provides an in-depth examination of the fundamental principles, mechanisms, and applications of toxicology, with a strong emphasis on their relevance to environmental and occupational health (EOH). Students explore how chemical, physical, and biological agents interact with biological systems, leading to adverse effects at the molecular, cellular, organ, and ecosystem levels. Particular attention is given to toxicant disposition, target-organ toxicity, non-organ-directed effects (such as carcinogenesis and developmental toxicity), major classes of toxic agents, environmental toxicology, and the practical applications of toxicology in risk assessment, occupational safety, regulatory decision-making, forensic analysis, and public health protection.

Using Casarett & Doull’s Essentials of Toxicology, Fourth Edition (Klaassen & Watkins, 2021) as the core textbook, the course integrates classic toxicological science with contemporary EOH challenges, including workplace exposures, environmental pollution, emerging contaminants, and climate-related toxicological risks. Through critical analysis of case studies, risk-assessment frameworks, and regulatory approaches, students develop the advanced competencies required to conduct independent research, inform policy, and implement evidence-based interventions in environmental and occupational health settings. The course is structured into five learning periods aligned with the textbook’s seven units, enabling progressive mastery from foundational concepts to applied toxicology.

Credits: 3 (doctoral)

Format: Self-paced or structured online doctoral seminar with required readings, critical reviews, and a final research paper or capstone project.

Prerequisites: Admission to the EUCLID PhD in Environmental and Occupational Health or equivalent graduate-level preparation in biology, chemistry, or public health.

Course Objectives

The primary objectives of EOH-TOX are to enable PhD students to:

1. Master the core scientific principles of toxicology and apply them to real-world environmental and occupational exposure scenarios.
2. Analyze the disposition (absorption, distribution, metabolism, and excretion) and toxicokinetics of xenobiotics and evaluate their implications for human and ecological health.
3. Evaluate mechanisms of toxicity, including organ-specific, non-organ-directed, and transgenerational effects.
4. Assess major classes of toxic agents and environmental toxicants in the context of occupational settings, pollution, and ecosystem health.
5. Apply toxicological knowledge to risk assessment, regulatory decision-making, clinical and forensic toxicology, and the development of prevention and mitigation strategies in EOH.
6. Critically review scientific literature and design research studies that address current and emerging toxicological challenges in environmental and occupational health.

Learning Outcomes

Upon successful completion of the course, students will be able to:

• Demonstrate comprehensive knowledge of the historical evolution, general principles, and mechanisms of toxicity, and articulate their relevance to EOH policy and practice.
• Explain the processes governing the disposition and toxicokinetics of toxicants and predict how these influence dose-response relationships and susceptibility in exposed populations.
• Identify and characterize non-organ-directed toxicities (e.g., carcinogenesis, genetic toxicity, developmental toxicity) and target-organ toxicities, linking them to specific environmental and occupational exposures.
• Evaluate the toxicological profiles of major classes of chemical agents, environmental pollutants, and physical agents, and assess their risks in workplace and community settings.
• Apply toxicological principles to practical applications, including occupational exposure limits, environmental risk assessment, forensic investigation, and the development of evidence-based interventions.
• Synthesize toxicological data to formulate research questions, critique peer-reviewed studies, and propose doctoral-level research projects or policy recommendations in environmental and occupational health.
• Communicate complex toxicological concepts effectively to scientific, regulatory, and public audiences.

Required Textbook

Klaassen, C. D., & Watkins, J. B., III (Eds.). (2021). Casarett & Doull’s Essentials of Toxicology (4th ed.). McGraw-Hill Education.

Syllabus: Five Periods of Learning

The course is organized into five instructional periods. Each period corresponds to specific units from the textbook and includes required readings from the assigned units, supplementary EOH-focused readings (journal articles, regulatory documents, and case studies), critical analysis assignments, and discussion forums. Students are expected to complete all readings, view the recommended YouTube video, and submit period-end assignments (e.g., literature critiques or mini-case analyses) that integrate toxicological principles with environmental and occupational health applications.

Period 1: Foundations of Toxicology – General Principles and Disposition of Toxicants Textbook Units: Unit 1 (General Principles of Toxicology) and Unit 2 (Disposition of Toxicants) Key Topics: Historical development of toxicology; principles of dose-response; mechanisms of toxicity; risk assessment fundamentals; absorption, distribution, metabolism (biotransformation), excretion (ADME); toxicokinetics and modeling. Focus in EOH: Application of principles to occupational exposure assessment, environmental dose modeling, and regulatory risk characterization.

Recommended YouTube Video: “Introduction To TOXICOLOGY” (broad foundational overview of toxicology principles, dose-response relationships, and key concepts) – https://www.youtube.com/watch?v=bnB_p8MeblM

Period 2: Non-Organ-Directed Toxicity Textbook Unit: Unit 3 (Non-Organ-Directed Toxicity) Key Topics: Chemical carcinogenesis; genetic toxicology; developmental toxicology. Focus in EOH: Transgenerational and population-level effects of environmental contaminants and occupational carcinogens; implications for vulnerable populations and reproductive health policy.

Recommended YouTube Video: “Chemical Carcinogenesis Explained: Cancer-Causing Agents, Stages, and Daily Exposures” (detailed mechanisms of chemical carcinogenesis, initiation/promotion, and relevance to everyday exposures) – https://www.youtube.com/watch?v=o1MUueW5ArY

Period 3: Target Organ Toxicity Textbook Unit: Unit 4 (Target Organ Toxicity) Key Topics: Toxic responses of the blood, immune system, liver, kidney, respiratory system, nervous system, visual system, cardiovascular system, skin, endocrine system, and reproductive system. Focus in EOH: Organ-specific effects from workplace chemicals (e.g., solvents, heavy metals) and environmental pollutants (e.g., air toxics, pesticides); clinical and epidemiological correlations.

Recommended YouTube Video: “How toxicants induce toxicity in liver, kidney, lung & brain?” (mechanisms of target-organ toxicity with clear examples across major systems) – https://www.youtube.com/watch?v=oxyoTY4LF0A

Period 4: Toxic Agents and Environmental Toxicology Textbook Units: Unit 5 (Toxic Agents) and Unit 6 (Environmental Toxicology) Key Topics: Major classes of toxic agents (pesticides, metals, solvents, radiation, plant and animal toxins, food-borne toxicants, nanoparticles); ecotoxicology; environmental fate and transport of toxicants; air, water, and soil pollution toxicology. Focus in EOH: Occupational exposure to industrial agents; ecological risk assessment; global environmental health challenges such as climate change and emerging contaminants.

Recommended YouTube Video: “Environmental Toxicology” (comprehensive overview of environmental toxicology principles, mechanisms, common pollutants, and real-world impacts) – https://www.youtube.com/watch?v=eIZr7M-kt2s

Period 5: Applications of Toxicology Textbook Unit: Unit 7 (Applications of Toxicology) Key Topics: Analytical and forensic toxicology; clinical toxicology; occupational toxicology; regulatory toxicology; risk management and communication; ethical considerations in toxicological research. Focus in EOH: Integration of toxicology into occupational health programs, environmental policy development, emergency response, and doctoral research design.

Recommended YouTube Video: “Discover the Basics of Toxicology and Risk Assessment” (practical applications including risk assessment, regulatory toxicology, and real-world EOH contexts) – https://www.youtube.com/watch?v=6fJ0Q4Z3_7s

Assessment & EUCLID Standards

– Five period response papers (critical analysis integrating readings + video).

– Create a 10 question Quiz

– Final integrative paper or oral examination (synthesizing the course).

– Grading: 60% papers + 40% final (per EUCLID norms).

– Student responsibilities: Complete all readings/videos independently, submit scholarly work demonstrating graduate-level synthesis, and prepare for possible oral defense.