Environmental Health and Toxicology

Slides:



Advertisements
Similar presentations
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 8 Lecture Outline.
Advertisements

Chapter 17 Human Health and Environmental Risks
Environmental Health and Toxicology
Environmental Health and Toxicology
Chapter 17 Human Health and Environmental Risks. Objectives Identify the three major categories of human health risks List the major historical and emerging.
1 ESC110 Chapter Eight: Environmental Health and Toxicology Principles of Environmental Science - Inquiry and Applications, 2nd Edition by William and.
Environmental Health and Toxicology
CH 8 - Environmental Health & Toxicology In some parts of Eastern Europe and the former USSR, up to 90% of all children suffer from environmentally linked.
Environmental Science Inquiry and Applications Cunningham • Cunningham
Chapter 17 Human Health and Environmental Risks. Three categories of human health risks physical biological chemical.
Toxicology please grab a notes sheet. Toxicology: the study of the adverse effects of chemicals on health. Toxicity: how harmful something is. Depends.
The Environment and Human Health
APES Get out Ecological Footprint Assignment. Chapter 17 Environmental Hazards & Human Health.
Environmental Hazards and Human Health By Brittney Jones
1 William P. Cunningham University of Minnesota Mary Ann Cunningham Vassar College Copyright © The McGraw-Hill Companies, Inc. Permission required for.
Environmental Health & Toxicology. Health & Disease The common disease of sentient beings is to be diligent and earnest when catastrophe strikes but lax.
Human Health and Environmental Risks Chapter 17. Categories of Human Health 3 major categories of risks a. physical – natural disasters, radon, UV rays.
Chapter 17 Human Health and Environmental Risks
1 William P. Cunningham University of Minnesota Mary Ann Cunningham Vassar College Copyright © The McGraw-Hill Companies, Inc. Permission required for.
1 Chapter 8: Environmental Health and Toxicology Hong Kong residents concerned about SARS Copyright © The McGraw-Hill Companies, Inc. Permission required.
Chapter 17 Human Health and Environmental Risks. What is Risk? Risk: possibility of suffering harm from a hazard.
What risks do these pollutants pose to us? To determine this we need to understand the following.
Chapter 8: Environmental Health and Toxicology
Disability-Adjusted Life Year (DALY) combines premature deaths and loss of healthy life resulting from illness or disability. (1.4 billion a year) 90%
Key Concepts  Types of hazards people face  Methods of toxicology  Types and measurement of chemical hazards  Types and effects of biological hazards.
 Physical hazards = occur naturally Earthquakes, volcanoes, fires, floods, droughts Can’t prevent them, but can prepare for them Increase our vulnerability.
Chapter 15 Environmental Health, Pollution and Toxicology.
Chapter 15 Environmental Health, Pollution and Toxicology.
Environmental Hazards and Human Health Chapter 17.
Human Health and Environmental Risks
Page 1 Unit 7 Environmental hazards and human health- (ch 17)
Environmental Health and Toxicity- Reverse Lesson 1 Presented by Mrs. Perryman.
Chapter 17 Hazards and Risks. Questions for Today What is Risk and how do we handle Risk? What is a Hazard? What is Toxicology? What affects Toxicity?
Chapter 17 Human Health and Environmental Risks. Three categories of human health risks physical biological chemical.
ENVIRONMENTAL CHEMISTRY A Global Concern Chem-440 1/19/2016Dr Seemal Jelani1.
1 William P. Cunningham University of Minnesota Mary Ann Cunningham Vassar College Copyright © The McGraw-Hill Companies, Inc. Permission required for.
Chapter 17 Environmental Hazards & Human Health
Toxicology Toxicology—measure of how armful a substance is – Potential harm is dependent on Dosage Bioaccumulation—some molecules are absorbed & stored.
1 Environmental Health and Toxicology. 2 Reflection What problems are unique to each habitat? What problems are common to each habitat?
Environmental Hazards and Human Health. Are Baby Bottles & Food Cans Safe To Use? 1.Some synthetic chemicals act as hormone mimics and disrupt the human.
Chapter 17 Human Health and Environmental Risks. Three categories of human health risks physical biological chemical.
Chapter 20 – The Environment and Human Health Hong Kong residents concerned about SARS.
Students type their answers here
MEASUREMENT OF TOXICITY By, Dr. M. David Department of Zoology, Karnatak University Dharwad.
Risk, Toxicology & Human Health Chapter 10. I. Risk A.The probability of hazard (injury, disease, economic or environmental damage B. Risk Assessment.
Chapter 17 Human Health and Environmental Risks.  Key Ideas  Three major categories of human health risk: – physical – biological – chemical  Historical.
Environmental Health and Toxicology
Chapter 19 – The Environment and Human Health
Chapter 17 Human Health and Environmental Risks
Chapter 17 Human Health and Environmental Risks
Chapter 08 Lecture Outline
Environmental Health, Pollution and Toxicology
THE DOSE MAKES THE POISON
Chapter 17 Human Health and Environmental Risks
Environmental Toxicology
Toxicology (Impact of poisons).
Chapter 17 Human Health and Environmental Risks
Chapter 17 Human Health and Environmental Risks
Chapter 17 Human Health and Environmental Risks
Chapter 17 Human Health and Environmental Risks
Module 57 Toxicology and Chemical Risks
Environmental Health and Toxicology
Chapter 17 Human Health and Environmental Risks
Chapter 17 Human Health and Environmental Risks
Apes Ch 11 Risk, Toxicology, and Human Healthy
Environmental Health Health - a state of physical, mental, and social well-being Disease - an abnormal change in the body’s condition that impairs physical.
Risk, Toxicology, and Human Health
Environmental Health, Pollution and Toxicology
Chapter 17 Human Health and Environmental Risks
Chapter 17 Human Health and Environmental Risks
Presentation transcript:

Environmental Health and Toxicology Chapter 9 Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Outline: Environmental Health Hazards Infectious Organisms Antibiotics and Pesticide Resistance Toxic Chemicals Movement and Fate of Toxins Minimizing Toxic Effects Measuring Toxicity Risk Assessment Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

ENVIRONMENTAL HEALTH HAZARDS Health - A state of complete physical, mental, and social well-being. Disease - A deleterious change in the body’s condition in response to an environmental factor. Diet and nutrition, infectious agents, toxic chemicals, physical factors, and psychological stress all play roles in morbidity (illness) and mortality (death). Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Infectious Organisms For most of human history, the greatest health threats have been pathogenic organisms and accidents or violence. Infectious diseases are still responsible for about 24% of all disease-related deaths. Majority of these deaths in poorer countries with poor nutrition, sanitation, and vaccination programs. AIDS now largest single cause of communicable death in the world. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Morbidity and Quality of Life Death rates do not tell everything about burden of disease. Total economic and social consequences of diseases are difficult to obtain. Disability-Adjusted Life Year (DALY) combines premature deaths and loss of healthy life resulting from illness or disability. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Disability-Adjusted Life Year WHO reports communicable diseases are responsible for nearly half of all 1.4 billion DALY’s lost each year. About 90% of all DALY losses occur in developing world where one-tenth of all health care dollars are spent. Malnutrition exacerbates many diseases. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Emergent Diseases An emergent disease is one never known before, or has been absent for at least 20 years. An important factor in the spread of many diseases is the speed and frequency of modern travel. Foot and Mouth Disease Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Antibiotic and Pesticide Resistance Protozoan parasite that causes malaria is now resistant to most antibiotics, while the mosquitoes that transmit it have developed resistance to many insecticides. Short life spans. Speeds up natural selection and evolution. Human tendency to overuse pesticides and antibiotics. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Antibiotic Use At least half of the 100 million antibiotic doses prescribed in the US every year are unnecessary or are the wrong drug. Many people do not finish full-course. More than half of all antibiotics manufactured in the US are routinely fed to farm animals to stimulate weight gain. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Toxic Chemicals Dangerous chemicals are divided into two broad categories: Hazardous - Dangerous Flammable, explosive, irritant, acid, caustic. Toxic - Poisonous Can be general or very specific. Often harmful even in dilute concentrations. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Toxic Chemicals Allergens - Substances that activate the immune system. Antigens - Allergens that are recognized as foreign by white blood cells and stimulate the production of specific antibodies. Other allergens act indirectly by binding to other materials so they become antigenic. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Toxic Chemicals Neurotoxins - Special class of metabolic poisons that specifically attack nerve cells. Different types act in different ways Heavy Metals kill nerve cells. Anesthetics and Chlorinated Hydrocarbons disrupt nerve cell membranes. Organophosphates and Carbamates inhibit signal transmission between nerve cells. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Toxic Chemicals Mutagens - Agents that damage or alter genetic material. Radiation Teratogens - Specifically cause abnormalities during embryonic growth and development. Alcohol - Fetal Alcohol Syndrome Carcinogens - Substances that cause cancer. Cigarette smoke Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

US Age-Adjusted Cancer Death Rates Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Natural and Synthetic Toxins Many natural chemicals are very dangerous while many synthetic chemicals are relatively harmless. Both plants and animals produce chemicals similar to neurotransmitters, hormones, and regulatory molecules. Arsenic and cyanide are both natural. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

MOVEMENT, DISTRIBUTION, AND FATE OF TOXINS Solubility - One of most important characteristics in determining the movement of a toxin. Chemicals are divided into two major groups: Those that dissolve more readily in water. Those that dissolve more readily in oil. Water soluble compounds move rapidly through the environment, and have ready access to most human cells. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Bioaccumulation and Biomagnification Cells have special mechanisms for Bioaccumulation - Selective absorption and storage. Dilute toxins in the environment can build to dangerous levels inside cells and tissues. Biomagnification - Toxic burden of a large number of organisms at a lower trophic level is accumulated and concentrated by a predator at a higher trophic level. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Persistence Some chemical compounds are very unstable and degrade rapidly under most conditions, thus their concentrations decline quickly after release. Others are more persistent. Stability can cause problems as toxic effects may be stored for long period of time and spread to unintended victims. (DDT) Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Bioaccumulation Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Chemical Interactions Antagonistic Reaction - One material interferes with the effects, or stimulates the breakdown, of other chemicals. Additive Reaction - Effects of each chemical are added to one another. Synergistic Reaction - One substance exacerbates the effect of the other. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

MECHANISMS FOR MINIMIZING TOXIC EFFECTS Every material can be poisonous under certain conditions. Most chemicals have a safe threshold under which their effects are insignificant. Metabolic Degradation In mammals, the liver is the primary site of detoxification of both natural and introduced poisons. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Excretion Effects of waste products and environmental toxins reduced by eliminating via excretion. Breathing Kidneys Urine Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. MEASURING TOXICITY Animal Testing Most commonly used and widely accepted toxicity test is to expose a population of laboratory animals to measured doses of specific toxins. Sensitivity differences pose a problem. Dose Response Curves LD50 - Dose at which 50% of the test population is sensitive. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Population Sensitivity Variations Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Acute vs. Chronic Effects Acute Effects - Caused by a single exposure and result in an immediate health problem. Chronic Effects - Long-lasting. Can be result of single large dose or repeated smaller doses. Very difficult to assess specific health effects due to other factors. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. RISK ASSESSMENT Factors influencing risk perception: Rating risks based on agendas. Most people have trouble with statistics. Personal experiences can be misleading. We have an exaggerated view of our abilities to control our fate. News media sensationalizes rare events. Irrational fears lead to overestimation of certain dangers. Fear of the unknown. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Accepting Risks Most people will tolerate a higher probability of occurrence of an event if the harm caused by that event is low. Harm of greater severity is acceptable only at low levels of frequency. EPA generally assumes 1 in 1 million is acceptable risk for environmental hazards. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

ESTABLISHING PUBLIC POLICY It is difficult to separate the effects of multiple hazards and evaluate their risks accurately, especially when exposures are near the threshold of measurement and response. May not be reasonable to mandate protection, no matter how small the risk, from every potentially harmful contaminant in our environment. Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed. Summary: Environmental Health Hazards Infectious Organisms Antibiotics and Pesticide Resistance Toxic Chemicals Movement and Fate of Toxins Minimizing Toxic Effects Measuring Toxicity Risk Assessment Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.

Cunningham - Cunningham - Saigo: Environmental Science 7th Ed.