Course: Public Health Toxicology
Students examine basic concepts of toxicology as they apply to the effects of environmental agents, e.g. chemicals, metals, on public health. We discuss the distribution, cellular penetration, metabolic conversion, and elimination of toxic agents, as well as the fundementallaws governing the interaction of foreign chemicals with biological systems. Students focus on the application of these concepts to the understanding and prevention of morbidity and morality resulting from environmental exposures to toxic substances through case study.
Upon successfully completing this course, students will be able to:
- Describe the chemical properties and the biological processes which modulate the toxicokinetics of chemical agents of public health importance
- Explain the significance of biotransformation reactions as a determinant of the toxicokinetic and toxicodynamic activities of chemicals
- Describe molecular, cellular and pathophysiological responses resulting from exposure to chemical agents relevant to human health
- Identify underlying susceptibility factors which contribute to the ability of chemicals to elicit bioeffects which contribute to human disease
- Explain the science underlying testing for the ability of chemicals to elicit adverse human health effects
- Put into perspective the role of toxicology in the risk assessment process
- Discuss in depth the toxicology of selected organs and agents
Introduction to Online Learning; a background in college biochemistry and cell biology strongly encouraged.
There is no required text. However, there are assigned readings for each lecture that are accessed through e-reserves.
Excellent reference texts for those who want more detailed information are:
- Casarett and Doull’s Essentials of Toxicology, 8th (or earlier) edition, C.D. Klaassen and J.B. Watkins III, eds. McGraw Hill Medical, NY, 2013.
- Principles and Methods of Toxicology. Fifth Edition. A. Wallace Hayes (ed). CRC Press, Boca Ratan, 2008. (Older editions also contain basic information that may be helpful.)
There are two assignments. Specific instructions for each assignment can be found on the Assignments page. Be sure to read them!
> Assignment 1:Exposure to hazardous air pollutants (HAPs), or air toxics, are of major concern in US communities. The goal of this assignment is for you to prepare a paper on a specific HAP in a community of your choice, its source and potential for causing an adverse health effect.
> Assignment 2:Each day we are all exposed to environmental chemicals through our diet, personal care products we use, occupation, etc. Your assignment is to become aware of exposures that you have incurred over the past week or two. Choose one chemical that you have been exposed to and then in the context of what you have learned from the BASIC PRINCIPLES (i.e. exposure, absorption, metabolism, etc.) and APPLIED TOXICOLOGY (i.e. potential for causing adverse effects, risk from exposure, biomarker of exposure, etc.) lectures, write an OP/Ed article** on the importance of this chemical and your concerns about exposure to it with regard to potential adverse health effects it may cause.
The course is intended for students in professional degree programs who wish to gain a broad understanding of the basic concepts and principles of toxicology. It also serves as an introductory course for those students in academic degree programs who are planning on following a course of more advanced study in the science of toxicology.
Methods of Assessment
Student evaluation is based on:
Weekly online quizzes
Two individual written assignments
- Basic principles: factors that affect toxicity
- Toxicokinetics: absorption, distribution, excretion, and biotransformation
- Toxicity testing, dose response and risk assessment
- Environmental carcinogenesis
- Biomarkers of exposure and susceptibility factors
- Approaches to primary and secondary prevention
- Hepato and renal toxicology: basic principles and specific examples
- Reproductive and developmental toxicology: basic principles and specific examples (e.g., endocrine disruptors, thalidomide)
- Immunotoxicology: basic principles, cutaneous and pulmonary hypersensitivity
- Persistent organic pollutants (POPs) and dioxins
- Bone marrow toxicity: benzene as a case study
- Metal toxicology: mercury, cadmium
- Ozone, a criteria air pollutant
- Nanoparticle toxicology
Course content is divided into two modules. Within each module are individual lectures, which are presented sequentially and should be completed in that order. Lectures combine audio presentation and slides—just like attending lectures in class. You may return to any previous lecture at any point and review its contents at your convenience.
On each lecture's main page, you will find a listing of the section topics, links to the lecture materials, a listing of reading assignments, and links to Web resources. You'll also find any required course work
We strongly encourage you to initiate and participate in the Discussion Forum with your fellow students. However, you will not be graded on your participation in these discussions.
Grades will be determined as follows:
Midterm exam: 100 points
Final exam: 100 points
Weekly quizzes: 84 points (7 quizzes, each worth 12 points)
Assignment 1: 50 points
Assignment 2: 30 points
Total points possible: 364
Final grade: The total number of possible points will be 364. The final grade will be determined based on the number of points achieved by summing the total points on the exams, quizzes, and assignments versus the total number of points possible (364) and determining a final grading scale. The final grading scale may be curved at the discretion of the faculty.
- >90%of total points = A
- 89-80% = B
- 79-70% = C
- 69-60% = D
- <59% = F
This course has two primary goals:
- To introduce you to the underlying principles governing the interactions of foreign chemicals (xenobiotics) with biological systems
- To help you develop an understanding of the kinds of toxic manifestations that can occur as a result of chemico-biological interactions
The first goal will be accomplished in Modules 1–2 (Lectures 1–7) by presenting lectures emphasizing the principles of chemical distribution, cellular penetration, metabolism, and elimination. Additional topics covered in these lectures will include: toxicity testing, dose-response and risk assessment, the mechanisms of carcinogenesis by environmental agents, biomarkers and susceptibility factors and approaches to primary and secondary prevention.
The second course goal will be accomplished in Module 3 (Lectures 8–16) by the presentation of case studies. The case studies are designed to further develop and illustrate the basic principles and mechanisms of toxicology as applied to various chemicals or classes of chemicals in selected tissues and organs.
Health Toxicology is a four-credit course. It consists of three hours of class time equivalent plus six one-hour LiveTalk discussion sessions (LiveTalk sessions not available in JHSPH Open CourseWare). In addition, students are expected to spend at least two hours outside of class for every hour spent in class to complete the readings assigned to each lecture and the two written assignments.
The most recent student evaluations for this course indicate that successfully completing the course involved a range of time commitments, as follows:
- 21% of all students evaluated spent fewer than 11 hours per week
- 52% of all students evaluated spent 11–15 hours per week
- 28% of all students evaluated spent 16–20 hours per week
- 0% of all students evaluated spent more than 20 hours per week