Session 3: Pollution

Question 1

Overall, describe water pollution.

Answer 1

Can occur from urban, industrial, or agricultural sources and enters ground water or directly into surface waterways from runoff. Some pollution alters the water pH, temperature, and turbidity (higher amounts of solid particles/cloudiness/sediments), and can also add harmful substances to the water.

Question 2

What are the elements and sources of water pollution?

Answer 2

sediment, sewage, infectious particles, organic compounds, thermal changes, radioactive pollution, inorganic chemicals, plastic waste, and inorganic plant nutrients.

Question 3

How does sediment count as water pollution?

Answer 3

soil erosion (e.g. top soil being washed away) and silt/sediment built up can alter waterways and their habitats.

Question 4

How does sewage count as water pollution?

Answer 4

while treatment is often carried out and minimises the impact, human waste, soaps, and detergents are often released into waterways and the oceans

Question 5

How do infectious particles count as water pollution?

Answer 5

disease causing microbes from animals and humans can be a major issue particularly with drinking water (can come from sewage, etc.)

Question 6

How do organic compounds count as water pollution?

Answer 6

organic compounds, meaning they come from living matter, including fossil fuels, such as oil spills and manufacturing waste products such as dioxins can be released into waterways and be toxic to organisms.

Question 7

How do thermal changes count as water pollution?

Answer 7

definition: heat (pollution)

some industries like power generation can increase water temperatures which can alter habitats and reduce oxygen levels.

Question 8

How does radioactive pollution count as water pollution?

Answer 8

mining and nuclear power stations can release dangerous levels of radioactive material, generally as waste that pollutes the soil and waterways that is dangerous because it can last a very long time

Question 9

How do inorganic chemicals count as water pollution?

Answer 9

mining, acid rain, heavy metals (mercury, arsenic, etc.) and many chemicals are toxic and can contaminate water (they sometimes come from the soil)

Question 10

How does plastic waste count as water pollution?

Answer 10

every year, about 8 million tons of plastic waste escapes into the oceans from coastal nations and plastics can take up to 400 years to break down

Question 11

How do inorganic plant nutrients count as water pollution?

Answer 11

artificial fertilisers with large amounts of nitrogen and phosphorous can lead to accelerated nutrient enrichment, causing algal blooms and weed growth (eutrophication)

Question 12

Define eutrophication and where and why it occurs.

Answer 12

The enrichment of an ecosystem (typically aquatic) with chemical nutrients (nitrates, phosphates, etc.). It is a common occurrence in Australia and can be caused by nutrients being leached from soil by rainfall or released as part of sewage. It is a common occurrence around agricultural land.

Question 13

What are the effects of eutrophication?

Answer 13

• algal blooms (which can block sunlight for other plants and kill them)
• a subsequent spike in the number of decomposers as algae dies
• increased biochemical oxygen demand (BOD) due to the high rate of decomposition by saprotrophic bacteria (they consume available quantities of dissolved oxygen leading to deoxygenation)
• all of the above stress the survival of aquatic organisms, potentially leading to reduction in biodiversity

Question 14

Describe air pollution.

Answer 14

Consists of gases, liquids, or solids present in the atmosphere at levels high enough to be harmful to organisms. It is concentrated around areas of high/dense human population and industry, and can sometimes affect enclosed/indoor environments, e.g. buildings, cars, etc. Can be caused by forest fires, volcanic activity, burning of fossil fuels, industry, and vehicles.

Question 15

What is smog?

Answer 15

Sunlight reacting with a mixture of pollutants from industry and vehicles.

Question 16

What are the air pollutants?

Answer 16

carbon monoxide, hydrogen sulfides, sulfur dioxides, nitrogen oxides, smoke, lead, ozone, and hydrocarbons.

Question 17

Describe carbon monoxide air pollution.

Answer 17

Caused by power plant and industrial emissions, fossil fuel combustion, petrol and diesel combustion, and bushfires. Carbon monoxide poisoning limits the body’s ability to transport oxygen to where it needs it and can cause health problems ranging from headaches to death.

Question 18

Describe hydrogen sulfides air pollution.

Answer 18

Caused by fossil fuel combustion, oil refineries, wood pulp processing, power plant and industrial emissions, and oil and natural gas extraction. Can cause eye and respiratory system irritation and can be life threatening depending on its concentration.

Question 19

Describe sulfur dioxides air pollution.

Answer 19

Caused by power plant and industrial emissions, fossil fuel combustion, and volcanoes. Mainly affects the respiratory system (lung function) but can also irritate the eyes.

Question 20

Describe nitrogen oxides air pollution.

Answer 20

Caused by power plant and industrial emissions, burning fossil fuels, and petrol and diesel combustion engine emissions. It forms photo-chemical smog which can irritate the eyes and nose, also affects plant growth.

Question 21

Describe smoke air pollution.

Answer 21

Mainly caused by Power plant and industrial emissions, but also burning fossil fuels, and petrol and diesel combustion engine emissions. Can cause irritation or more serious effects on cardiovascular and respiratory systems.

Question 22

Describe lead air pollution.

Answer 22

Caused by petrol and diesel combustion engine emissions, and ore and metals processing. Lead pollution/poisoning causes damage to the nervous system, convulsions, and comas.

Question 23

Describe ozone air pollution.

Answer 23

In the presence of direct sunlight, pollution from industry and vehicles react to form ozone (caused by vehicles, industry emissions, fossil fuel combustion). Can cause sick building syndrome and other damage to respiratory system.

Question 24

Describe hydrocarbons air pollution.

Answer 24

Caused by petrol and diesel combustion engine emissions. Can cause pneumonia and other effects to respiration.

Question 25

What does it mean for pollutants to move through an ecosystem?

Answer 25

Like nutrients and energy, other substances, like pollutants (e.g. plastics), can move through an ecosystem and cause two problematic environment issues known as bioaccumulation and biomagnification. E.g. plastics, which do not break down, instead they exist as microplastics that can cycle for hundreds of years, if not more.

Question 26

What is bioaccumulation?

Answer 26

Refers to how pollutants enter a food chain or food web. It involves an increase in concentration of a pollutant from the environment to the tissues of
an organism. Smaller, simpler organisms towards the bottom
of a food chain will often absorb these
pollutants more easily.

Question 27

What is biomagnification?

Answer 27

Refers to a pollutants ability
to increase in concentration as it moves from
one trophic level to the next. It involves an increase in concentration from
one link in a food chain to another due to the
relative amount each organism in the chain
consumes.

Question 28

For biomagnification to occur, the pollutant must be:

Answer 28

long lived (doesn’t break down easily), mobile, soluble in fats (doesn’t readily dissolve and be excreted - accumulates in fat tissue), and biologically active (can affect living matter).

Question 29

What is an indicator species? and why use them?

Answer 29

A species whose presence, absence or abundance reflects a specific environmental condition, habitat or community. Indicator species may provide information on the overall health of an ecosystem, reflect a particular environmental condition, such as pollution, and be indicative of a particular habitat type or biological community. Indicator species can provide early warning of environment changes and be used to assess the health of an environment or ecosystem - they can be a useful management tool. Indicator species like their environment a certain way, so whether or not the species is present can tell you about the ecosystem.

Question 30

How do indicator species show changes in the environment?

Answer 30

increase or decrease in abundance, presence or absence, change in behaviour, and/or change in physiological or chemical make up. E.g. different invertebrate species are able to tolerate different levels of water pollution and so the composition of the species within a study area can indicate the level of pollution.

Question 31

What is a biotic index?

Answer 31

A form of measurement that compares the relative frequency of indicator species and provides an overall environmental assessment of an ecosystem. A change in the biotic index indicates a change in environmental conditions - high biotic index indicates an abundance of pollution sensitive organisms = unpolluted environment (and vise versa, low biotic index = polluted environment).

Question 32

What is the biotic index equation?

Answer 32

Sum of (number of individuals of a species x tolerance rating of a species) / total number of individuals collected

Question 33

How do bioaccumulation and biomagnification differ?

Answer 33

Bioaccumulation refers to toxins/pollutants accumulating within the organism, whereas biomagnification refers to toxins/pollutants accumulating throughout trophic levels.

Question 34

Why are bioaccumulation and biomagnification bad?

Answer 34

They negatively affect organisms, they can affect functions and systems, e.g. digestion, reproduction, etc and often lead to the death of the organism.

Question 35

Summarise DDT and its impact on organisms.

Answer 35

DDT was a modern synthetic insecticide/pesticide used to control diseases (typhus & malaria) by controlling the insect carriers of the disease. In birds, high concentrations of DDT is known to lead to disturbance in their calcium metabolism which causes premature breaking of eggs (thinning eggshell). In humans, it has been linked to cancer, reproductive problems, and developmental disorders. DDT is now banned as its cons of damage to the environment and humans outweighed the pros (effective, cheap, long-lasting).

Question 36

Summarise the impact of microplastics on the environment.

Answer 36

It is plastic pollution formed from plastic produced to be that size or from the breakdown of larger plastics. It can be harmful when ingested (cause damage to organs, be toxic/have toxic chemicals, and/or spread pathogens/parasites). As one example, ingestion of microplastics has led to malnutrition, starvation, and death for Laysan Albatross because it can cut up their stomachs and make them feel full. In sea turtles, ingestion can harm their intestines and turtles often become dangerously entangled in plastics.

Question 37

What does it mean to use indicator species passively or actively?

Answer 37

Passively means just observing. Actively means changing the environment and observing the results.