5.3: Environmental Hazards and Human Health

Risk

the probability of suffering harm from some sort of hazard

risk- hazard examples

injury, disease, death, economic loss

Possibility

the event could happen

Probability

the chances of the event happening

three parts of risk assessment

hazard identification

probability of risk

consequence of risk

four parts of risk management

compare risks

risk reduction

risk reduction strategy

financial commitment

____ can play a big role in how we view risk

media

media’s role on risk assessment example

avian bird flu killed no one in US

common flu kills 35k ppl in US per year

5 types of hazards that humans face

biological

chemical

physical

cultural

lifestyle choices

Biological hazards

pathogens infecting humans

pathogens

living organism that causes disease in another organism

pathogen examples

bacteria

viruses

parasites

protozoa

fungi

Chemical hazards

in the air, water, soil, or food

chemical hazards examples

mercury in fish

radon in ground

ozone in troposphere

physical hazard examples

fire

earthquakes

tsunami

floods

hurricanes

Cultural hazards examples

bad working conditions

unsafe highways

poverty

lifestyle choices hazard examples

smoking

drinking

drugs

unprotected intercourse

overeating

3 examples of high risk health problems

indoor/outoor air pollution

pesticide residue on food

worker exposure to industrial or farm chemicals

3 examples of high risk ecological problems

global climate change

ozone depletion

loss of biodiversity

medium risk ecological problems (4)

acid deposition

pesticides

airborne toxic chemicals

toxic chemicals, nutrients, and sediment in surface water

3 examples of low risk ecological problems

oil spills

groundwater pollution

acid runoff

risk analysis

identify hazards and evaluate and ranking risk, making decisions about reducing risks and then informing decision makers and the public

what are statistical probabilities based on

past experience, animal testing, tests determining risk from older chemicals and technologies

what is the greatest risk to human’s reduced life span

poverty

what lifestyle choices can help reduce risk

avoid smoking, lose excess weight, eat healthy, exercise, drink minimal alcohol, avoid excess sunlight, practice safe intercourse

the more ____ a technological system, the more difficult it is to estimate _____

complex, hazarads

reliability

probability that a person/ device will complete a task w/o failing

reliability equation

technological reliability * human reliability= system reliability (%)

unfair distribution “not in my backyard” factor

no one wants landfills or power plants near them even though risk is small

so found in low income and minority areas

evaluating risk- fear

ppl over-estimate risk

worry more about unusual risks than common risks

new and unknown technologies have more “fear” to them

evaluating risk- degree of control

greater fear over things they can’t control

evaluating risk- catastrophic vs chronic risk

catastrophic events are more eye catching vs effects spread out over time don’t

evaluating risk- optimism bias

risks apply to other ppl but not them

evaluating risk- instant gratification

pleasure that behavior brings overrules brain’s realization of risk

non-transmissible disease

disease not caused by pathogen and not spread between people

non-transmissible diseases have multiple____ and develop _____

causes, slowly

non-transmissible disease examples

heart disease, cancer, asthma, malnutrition

as life expectancy ______ non transmissible diseases ______

increase, increase

transmissible disease

an infectious disease that can be transmitted from one person to another

transmissible is not always______

infectious

infectious disease

caused by pathogen

infectious disease examples

flu

HIV

Malaria

Chicken pox

spillover

inter-species spread of infectious disease

Genetic disease

passed from parent to offspring

what has caused the decrease of death by infectious disease after 1950

better health care, use of medicine, vaccination programs

as life expectancy increased the leading cause of death shifted to ______. why?

non-transmissible diseases.

body starts deteriorating with age and can’t defend itself as well

where are infectious diseases still a major threat

developing countries

what are the main pathways for infectious diseases to humans

air

food

water

animals

unsanitary habits

Epidemic

large-scale outbreak of an infectious disease in a particular country

Pandemic

outbreak of a disease becomes worldwide

pandemic example

AIDS

Disability Adjusted Life Years (DALYs)

measure of a disease’s burden

Tuberculosis

bacterial disease infecting 10m/ year killing 1.5m, easily infect other people

drug treatments effective, but allows bacteria to develop resistance to antibiotics if they cut treatment short and leave some bacteria in body

Multi-drug resistant TB

infects 500,000/year in Africa, China, India, Russia

people with multi-drug resistant TB must do what

be permanently quarantined from society bc it’s incurable

multi-drug resistant TB pose threats to who? and how?

health workers

mass transportation

what is needed to control TB spread

screening and control programs in developing countries (early detection)

develop new antibiotics

better treatment for people with AIDS (weaker immune system)

tuberculosis is density_______

dependent

what is the issue with treating viruses

few anti-viral drugs and they develop rapidly

three most widespread and dangerous viruses

Influenza (Flu)

Hepatitis B (HBV)

Human Immunodeficiency virus (HIV)

how is Influenza transmitted

bodily fluids and airborne

what groups does influenza kill mostly

young, old, immunocompromised, already sick

virulent strains of influenza can have a death rate of __%

80%

how many people did the Spanish flu kill

20-59 million

what do viruses do as they move between species

mutate and swap genetic material

what animals can flu infect

pigs

chickens

ducks

geese

1997 H5N1 bird flue

started in Asia, linked to Spanish flu

65% fatality rate

in chickens first, to humans in Hong Kong, then migratory birds

didn’t spread between humans easily, but w mutation it could

Hepatitis B virus

damages liver

sexually transmitted through exposure to infected blood, and from infected mother to infant

what does the CDC recommend to slow down HBV

campaign for increased vaccinations

increase testing

increase care and treatment for chronic HBV

HIV/ AIDS

sexually transmitted through blood

can only be slowed down

WHO priorities to slow HIV/AIDS spread (6)

reduce new infections

concentrate on those most likely to spread disease

provide free testing

advertising and education

provide low-cost drugs

increase funding for research and medicine development

West Nile virus

humans to mosquitoes that fed on birds w the disease

causes severe illness including encephalitis and meningitis

Ebola

from West Africa Equatorial region

high lethality

spread through contact with bodily fluids

Severe Acute Respiratory Syndrome (SARS) virus

showed up in China

human to human and animal to human

can lead to pneumonia

Covid-19

infected 700m people and killed 7m people

Malaria

mostly in Africa

caused by parasite, spread by vector

infects blood

deaths mostly in young children

describe how Malaria can be spread

female mosquito bites infected person, picks up parasite

mosquito passes parasite to another person

plasmodium moves to person’s liver and multiplies

blood transfusions and drug users can spread the parasite

the malarial cycle will repeat itself unless what?

immunity develops, treatment is given, the victim dies

why did malaria in the 1950s an 60s decrease

drain swamps

pesticides

killing plasmodium in patients

what are the reasons that malaria cases are increasing again

anopheles mosquitoes are pesticide resistant

plasmodium has become resistant to several drugs

clearing rain forests brings workers who contract and spread it

climate range increases range of anopheles mosquitoes

drug studies against malaria

artemisinins from wormwood

fungi acting as biological control

genetically modified mosquitoes to resist plasmodium or infertile females to outcompete natural species

low cost treatments for malaria

giving bed nets and window screens

zinc and vitamin A supplements for immunity

spraying homes with DDT

what are the simplest methods to help prevent deaths from infectious diseases

oral rehydration therapy

better sanitation

toxic chemical

any chemical substance that can cause temporary/ permanent harm or death

Carcinogens

cause or promote cancer

doesn’t develop for 10-40 years

Mutagens

damage DNA which can cause cancer

mutations in reproductive cells can be passed down generations

Teratogens

cause harm/ birth defect to developing fetus or embryo

premature births and low birth rate, and mental issues

teratogen examples

alcohol for pregnant women

pollution in China

what are the 3 major types of potentially toxic agents

carcinogens

mutagens

teratogens

Immune system

specialized cells that protect the body from disease and foreign substances

protects from cancer

what 3 things have been shown to weaken the immune system

arsenic

methylmercury

dioxins

Nervous system- neurotoxins

cause behavioral changes, learning disabilities, retardation, ADD, paralysis, and death

neurotoxin examples

PCBs

methylmercury

arsenic

lead

pesticides

Endocrine system

glands that release hormones

describe how hormones operate

use lock and key model with cell receptors

what do hormones help control

sexual reproduction

growth and development

learning

behavior

chemicals that mimic hormones

hormonally active agents (HAAs)

some HAA examples

aluminum

herbicides

mercury

BPA

hormone blockers

block action of hormones by blocking their attachment to receptors

HAA effect on sexual development and reproduction

mimic estrogen affecting female development

blockers affect androgen