the environment and human health chapter 20. toxicologists study the harmful effects of substances...

The Environment and Human Health

Chapter 20

Toxicologists study the harmful effects of substances on organisms?

Epidemiology is the study of the spread of diseases--Trace disease to find its origin and how to prevent it from spreading.

1. Estimate the risk2. Look at existing information3. Determine toxicity4. Risk to public

Risk Assessments

Pathogens are organisms that cause disease.

• TB and Whooping cough are spread through the air

• Cholera is spread in water• Malaria is carried by a

secondary host—a mosquito

Emerging viruses

• previously unknown• Ex. AIDS, West Nile, H1N1,

Avian flu• Vaccines are main

defense, but viruses are always changing and need a new vaccine for each change.

WHO’s estimates (World Health Org.)• Estimates the number of days of life lost to

death and disease per person each year.

Why do people in developing countries suffer greater health impacts?

•Main factor is the role of infectious diseases which are more common in crowded areas with poor sanitation.

•Ex. Tuberculosis and cholera

Food that is making a difference

• http://www.cbsnews.com/video/watch/?id=50136247n

• Chocolate can save a life!

Natural Sources of Pollution• Radon—radioactive gas that seeps

up from granite bedrock; causes cancer

• Particulates—dust, soot, volcanic ash, wildfires; irritate lungs

• Heavy metals—arsenic, lead, mercury; cause nerve damage

Lead Poisoning

• effects

Lead Poisoning and Mental Ability Lab

On the back of notes….Plot the data for each group—it is NOT a line or bar graph. You will have a cluster of data points to analyze when finished.

Human Activities cont.

• A. BURNING FOSSIL FUELS!! • B. Pesticides Ex. DDT• C. Industrial chemicals—exposed

every day at low rates. Ex. New buildings, carpets, cleaning fluids, and furniture

• D. Waste Disposal—much of the pollution is a byproduct of inadequate waste disposal

Human activities that pollute.

• Little is known (only 10% of commercial chemicals have been tested for toxicity)

• 1000 new chemicals introduced/year

• US Regulations have reduced our exposure—ex., pollution control devices on vehicles and factories

Antibiotic Resistance• Pathogens evolve resistance to

medicines used to kill them. • Ex. E.coli, salmonella, TB• SuperBugs

Climate Change/Global Warming are increasing the spread of some diseases.

Why?How is it spread?

Extreme Heat

• Heat stroke and dehydration

• Increased use of Electricity for air• conditioning

Extreme Weather Events

• Reduce availability of water, food, services, etc.

• Carbon monoxide poisoning from portable generators, water-borne illnesses, and mental health impacts (ptsd)

Reduced Air Quality• Increase in Ground Level Ozone

which damages lungs• Warm, stagnant air increases its formation

Changes in Allergens• Earlier spring pollen season• Spread of Ragweed (an invasive

species)

Food and Water-borne Diseases• Salmonella and other bacteria

grow faster in warmer climates• Flooding can cause sewage spills

which can contaminate crops and lakes, etc

Animal Borne Diseases• Higher temps increase the Area for

ticks to spread Lyme disease • West Nile and Malaria spread by

mosquitoes that need standing water for breeding

Plastic Rap (CS: Ion Flux p.6-7)

• What is BPA and where can it be found?

•Why is it used?

•List at least 3 adverse side effects of BPA.

•Why do big companies dislike the FDA’s study on BPA?

Avoiding ExposureProduct Safer Alternative

Plastic Baby Bottle   

Non-disposable plastic water bottle

Canned food   

Canned soft drink   

Plastic food container   

Body Burden Test

• Test to determine presence of various toxins in the body

• Planet in Peril (Disc 1, Ch. 12)

Environmental Racism??

• Are certain ethnic groups at greater risk for environmental health risks?

• Planet in Peril (Disc 2, Ch.11)

Cancer Cluster (CS: Paintball Gun Control)

• What is a “cancer cluster?”

• What do some believe to • be the cause of the • leukemia in so many • children in Fallon, NV • (List 3 different reasons)

So What Do We Do?

• BE AWARE—don’t be afraid to ask questions if things don’t seem right.

• BE EDUCATED—read labels, and watch for recalls, etc

• BE NATURAL—anytime you can eat/buy products that are in a natural state vs. processed, it will be better for you!

Erin Brockovich

• Based on a true story of PG&E Electric and the people of Hinkley, CA.