environmental science: chapter 8

5 types of Environmental Hazards and Sources

1. biological

2. physical

3. mechanical

4. psychosocial

5. chemical

• natural

• man-made

poverty

• 45% of deaths

• linked to population growth

• greatest risk factor for poor health

• minorities at risk

biological hazards

all forms of life and nonliving products they produce that can cause adverse health effects

• plants

• fungi

• viruses

• toxins

• bacteria

• insects

zoonotic infectious diseases

diseases transmissable to humans from vertebrate animals, spread by vectors

caused by:

• new agents

• known agents that occur in new spaces

Examples:

• zoonotic disease

• lyme disease

• southern tick associated rash illness

• babesiosis

• west nile virus

• covid-19

• powassan

• marbug virus

(can impact cats and dogs too)

factors driving the increase in infectious diseases

• climate

• land use conservation

• meat consumption

• economy

• migration

• war

different hazards for environmental health

• physical (radiation, noise, heat)

• mechanical

• psychosocial (stress)

• chemical (inorganic, organic)

physical hazards - radiation

1. ionizing radiation

• high energy, atoms vibrate and electron is removed from neutral atom, pair of ions are produced, highly reactive

2. non-ionizing radiation

• atoms vibrate but electrons are not removed

• low energy

• uv radiation from sun

physical hazards - noise

unwanted sounds

intensity of sound

depends on the frequency or tone of a sound

could lose hearing

physical hazards - heat

climate change

weather related cause of death

heat exhaustion, dehydration, can’t breathe

mechanical hazards

posed by transfer of mechanical energy

kinetic energy: the energy of motion

types:

• injury

• accidents

• occupational

• recreational

• home

psychosocial hazards - stress

stress is a negative or adverse reaction

increase in heart rate, blood pressure, respriration

chemical hazards

1. inorganic

• small molecules

• metals

• corrosive materials

• halogens: salt by direct union with metal

2. organic

• large molecules with carbon

• hydrocarbons, pesticides, solvents

how to improve environmental health issues

address poverty/population growth

access to health care

address climate change

better land management

stabilize government

toxicology

environmental toxicology

t: study of poisons, adverse effects of chemical on living organisms

et: study of the impacts of pollutants upon the structure and function of ecosystems

posion

any substance capable of producing a illness or death in a biological system, all poisons are hazardous but not all hazards

toxic substances and their health impacts

allergens: activate the immune systems

antigens: recognized as foreign by white blood cells and stimulates the production of antibodies

immune system depressants: pollutants that depress the immune system

endocrine disruptors: disrupt normal hormone functions

neurotoxins: attack nerve cells, extremely toxic and fast acting

mutagens: damage or alter genetic material

teratogens: cause abnormalities during embryonic growth and development

carcinogens: cause cancer, invasive, viruses, chemicals

factors that affect movement and impacts of toxins

solubility

route of exposure

bio-accumulation

bio-magnification

persistence