Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Environmental Hazard and Risk

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings I. Into to Environmental Hazards A. Environmental health = assesses environmental factors that influence human health and quality of life -Natural and human-caused factors are both considered B. There are 4 types of environmental hazards – physical hazards, chemical hazards, cultural hazards, and biological hazards -We can reduce risk by better environmental choices

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings I. Into to Environmental Hazards C. Physical hazards = occur naturally in our environment 1. Earthquakes, volcanoes, fires, floods, droughts, exposure to UV radiation 2. We can’t prevent them, but we can prepare for them 3. We increase our vulnerability by deforesting slopes (landslides), channelizing rivers (flooding), etc.

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings I. Into to Environmental Hazards D. Chemical Hazards = synthetic chemicals such as pesticides, disinfectants, pharmaceuticals 1. Harmful natural chemicals also exist

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings I. Into to Environmental Hazards E. Biological Hazards = result from ecological interactions 1. Viruses, bacteria, and other pathogens 2. Infectious (communicable, or transmissible) disease = other species parasitize humans, fulfilling their ecological roles -We can’t avoid risk, but we can reduce the likelihood of infection

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings I. Into to Environmental Hazards F. Cultural Environmental Hazards= result from the place we live, our socioeconomic status, our occupation, our behavioral choices -Smoking, drug use, diet and nutrition, crime, mode of transportation

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Smoking = Bad 2009 – 20% of Americans smoke 1965 – 42% of Americans smoke It is the leading cause of preventable death in America, killing 443,000 Americans each year. No Don, No! Don’t light it!

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings II. Biological Hazards A. Disease is a major focus of environmental health B. Despite our technology, disease kills most of us C. Disease has a genetic and environmental basis 1. Cancer, heart disease, respiratory disorders 2. Poverty and poor hygiene can foster illnesses

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings II. Biological Hazards D. Infectious diseases kill 15 million people per year 1. Half of all deaths in developing countries 2. Developed countries have better hygiene, access to medicine, and money E. Vector = an organism that transfers pathogens to a host

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Leading Causes of Death World-Wide 1.Cardiovascular disease (29%) 2.Infectious disease (26%) 3.Cancer (13%) Leading Causes of Death in U.S.A. 1.Cardiovascular disease (25.4%) 2.Cancer (23%) 3.Stroke (5.6%) / Chronic Lower Resp. Disease (5.3%)

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings II. Biological Hazards F. Many diseases are increasing, such as tuberculosis, acquired immunodeficiency syndrome (AIDS), and the West Nile virus G. Our mobility spreads diseases H. Diseases are evolving resistance to antibiotics I. Climate change will expand the range of diseases

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings III. Chemical Hazards A. Toxicology = the study of the effects of poisonous substances on humans and other organisms B. Toxicity = the degree of harm a toxicant can cause 1. “The dose makes the poison” = toxicity depends on the combined effect of the chemical and its quantity 2. Analogous to pathogenicity or virulence = the degree of harm of biological hazards that spread disease C. Toxicant = any toxic agent

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings III. Chemical Hazards D. Environmental Toxicology - Deals with toxic substances that come from or are discharged into the environment E. Studies the health effects on humans, other animals, and ecosystems 1. Focus mainly on humans, using other animals as test subjects 2. Can serve as indicators of health threats

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings III. Chemical Hazards F. The environment contains countless natural chemicals that may pose health risks G. But, synthetic chemicals are also in our environment -Every human carries traces of industrial chemicals 80% of U.S. streams contain at least trace amounts of 83 wastewater contaminants

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings III. Chemical Hazards H. Very few chemicals have been thoroughly tested I. 100,000 chemicals are on the market today -72,000 industrial -8,700 food additives -2,000 new chemicals introduced per year J. We don’t know the effects, if any, most have

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings K. Rachel Carson published Silent Spring in 1962, which began public debate over chemicals 1. Brought together studies to show DDT risks to people, wildlife, and ecosystems 2. In the 1960s, pesticides were mostly untested and were sprayed over public areas, assuming they would do no harm 3. The book generated significant social change

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings IV. Routes of chemical transport

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings IV. Routes of chemical transport A. Toxins may concentrate in water 1. Runoff carries toxins from large land areas to small volumes of surface water 2. Chemicals can leach into the soil 3. Chemicals enter organisms through drinking or absorption -Aquatic organisms are effective pollution indicators

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings IV. Routes of chemical transport B. Airborne toxicants travel widely - Because chemicals can travel by air, their effects can occur far from the site of chemical use C. Pesticide drift = airborne transport of pesticides D. Synthetic chemical contaminants are found globally -They appear in arctic polar bears, Antarctic penguins, and people living in Greenland

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings IV. Routes of chemical transport E. Toxins can degrade quickly and become harmless, or they may remain unaltered and persist for decades 1. Rates of degradation depends on temperature, moisture, and sun exposure F. Persistent chemicals have the greatest potential for harm G. Breakdown products = toxicants degrade into simpler products 1. May be more or less harmful than the original substance 2. DDT degrades into DDE, which is also highly persistent

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings IV. Routes of chemical transport H. Some toxicants can be excreted or metabolized -Fat-soluble toxicants are stored in fatty tissues 1. Bioaccumulation = toxicants build up in animal tissues 2. Biomagnification = toxicants concentrate in top predators -Near extinction of peregrine falcons and brown pelicans

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings IV. Routes of chemical transport I. Chemical toxicants also exist naturally and in our food -Don’t assume natural chemicals are all healthy and synthetic ones are all harmful J. Some scientists feel that natural toxicants dwarf our intake of synthetic chemicals 1. Natural defenses against toxins are effective against synthetic ones, too 2. Critics say natural toxins are more readily metabolized and excreted, and synthetic chemicals persist and accumulate

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings V. Risk analysis A.Environmental Risk Assessment involves understanding the potential for harm to people, organisms, and the greater environment posed by different hazards. B.Hazard, Exposure, and Risk are three terms used frequently, and these terms mean different, non- interchangeable things

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings V. Risk analysis C. Hazard = is the inherent potential for something to cause harm. Hazards range from minimal to deadly in terms of human injury, or from minimal to catastrophic damage to the environment, or a specific component of the environment (water, air, etc.) D. When thinking about overall risk, determining the severity of the hazard is important.

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings V. Risk analysis E. Exposure = What is the probability of being exposed to the risk? Can be based on occurrence (I only fly twice a year vs. drive times a day) or number of individuals (only 100 people of a city of 1 million live within a mile of the chemical plant)

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings V. Risk analysis F. Risk = The likelihood that the hazard will actually happen and cause harm. How probable is it that the hazard will actually happen? Risk = hazard x exposure (so how dangerous something is times the likelihood of actually being exposed to it, or the level or time of exposure)

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings V. Risk analysis G. Evaluating Environmental Risk by regulatory agencies or companies involves three steps: 1.Risk Assessment – What are the hazards? What is the toxicity and extent of exposure? 2.Risk Acceptance – What is the acceptable level of risk (based on social/economic/political considerations) 3.Risk Management – Determine policy with input from citizens, industry, and interest groups.

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings H. Risk Assessment 1.Risk assessment seeks to identify a potential hazard and determine the magnitude of the potential harm. 2.MANY companies, organizations do risk assessment 3. Developed nations have federal agencies to manage risk -The U.S. has the Centers for Disease Control (CDC), the EPA, and the Food and Drug Administration (FDA)

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings V. Risk analysis Question 1: Which is riskier, driving 25 miles a day or flying 1,000 miles per year? Risks: 1.3 deaths per 100,000,000 miles for driving 1.9 deaths per 100,000,000 miles for flying Question 2: Use the Risk Assessment Matrix, and determine the level of risk for the following 2 scenarios: 1.Students getting injured using 12 M HCl 2.Students getting injured using 1 M HCl

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings V. Risk analysis I. We try to minimize risk, but we often misperceive it -Flying versus driving J. We feel more at risk when we cannot control a situation -We fear nuclear power and toxic waste, but not smoking or overeating

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings K. Risk Acceptance 1.Most difficult in the risk- analysis process 2.EPA lists a 1 in 1 million risk as acceptable for most environmental hazards. 3. Scientific assessments are considered with economic, social, and political needs and values 4. Comparing costs and benefits is hard a. Benefits are economic and easy to calculate b. Health risks (costs) are hard-to-measure probabilities of a few people being affected

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings L. Risk Management 1.Risk management is the policy put in place that is determined from the research as well as economic factors. 2.All levels of pollutant contaminants (air, water, toxins) that are set nationally and internationally are a result of implementing risk management. 3.Most companies have risk management plans in place.

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings M. Federal Risk Management M. Federal agencies apportion responsibility for tracking and regulating synthetic chemicals 1. FDA: food, food additives, cosmetics, drugs, and medical devices 2. EPA: pesticides 3. Occupational Safety and Health Administration (OSHA): workplace hazards O. Many public health and environmental advocates fear it isn’t enough 1. Many synthetic chemicals are not actually tested 2. Only 10% have been tested for toxicity 3. Fewer than 1% are government regulated

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings N. One approach to determining safety 1. Innocent until proven guilty approach: generally assumes products/chemicals are safe unless demonstrated negative event occurs -Benefits: not slowing down technological innovation and economic advancement -Disadvantage: putting into wide use some substances that may later on turn out to be dangerous, big recalls

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings O. Precautionary principle approach: General assumption that chemicals/products are inherently dangerous, must prove safe before released on the market 1. Far fewer recalls 2. Identifies troublesome toxicants before they are released 3. But, this may impede the pace of technology and economic advance

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings P. Philosophy affects policy Different nations use different policies; most use a mix between the “innocent until proven guilty” principle and the precautionary principle -Europe is shifting more towards the precautionary principle -Industries like the “innocent until proven guilty” approach because it allows them to produce more and make more money

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Two approaches for determining safety