GEOG10161 – Environmental Pollution
Week 1 – Introduction
Definition of pollution – any substance introduced into the environment which
adversely affects the usefulness of a resource, as well as adversely impacting human
health and the ecosystems/natural environment
The type of pollutant substances (many substances can be pollutant, it mainly
depends on the amount, which will drive the impact):
- Natural – organic chemical = e.g. oil, inorganic chemicals = e.g. metals (mercury)
- Anthropogenic – organic chemical = e.g. pesticides
Pollutant – mobile
Pollutants discharged into the atmosphere are carried by the wind, which is one of
the key ways in which pollutants are transported away from the source and across
boundaries, e.g. all the way to the poles
Another key way in which pollutant is transported is via the hydrological cycle,
through the flow of water at the surface or in the ground. Lakes are the key congilate
for moving pollutant from the terrestrial zone to the fluvial environment (water
environment). Water sources, like aquifers, can become contaminated because
urban areas can introduce pollutants which get transported below ground in the
aquifer. The polluted aquifer may then get upwelled to the surface somewhere far
away through wells
Furthermore, the artificial drainage of polluted water via pipes, as it moves and
discharge the pollutant to the environment. E.g. sewage
Moreover, the ocean can become contaminated by pollutant due to accidents or
intentional introduction through dumping
Pollutant – change form
Pollutant can change into different substances as it evolves, it can become toxic, in
which there are multiple drivers that underpin the change
The physical breakdown, chemical or biological reaction can change the form of the
pollutant
The changes in which the pollutant undergo can change the toxicity of the substance
– its relative impact on humans and the environment
Microbes can remove and control pollutants, as it can break them down, through
bioremediation (introducing microorganisms to consume and breakdown
pollutants). In order to improve the environment which was once polluted
Pollution extremes
There’s different levels of pollution extreme:
- Some are very obvious (visible) and cause devastations, such as big accidents
whereby the impact is very well-known
- However, there are pollutions that’s less obvious (it’s invisible, odourless and
tasteless)
, Pollution impacts formula (PAT) = population x affluence x technology
Chemical toxicity
Pollution is concerning to the environment because it
toxic to the terrestrial and/or aquatic ecosystem and
human health
All substances are potentially toxic, whether it’s natural
or anthropogenic, but it’s underpinned by the dose. As
some pollutant only require a small dose to be highly
toxic, while other substances require high dosage to be
toxic, e.g. gold. So, the dose makes the poison
This is known as the dose-effect relationship
Acute and chronic toxicity
Acute toxicity – refers to the adverse effect seen soon after a one-time exposure to
the chemical substance. Acute toxicity usually occurs due to accidents, e.g. the
mining accident which released cyanide and other toxic metals to the Tiszar river in
Hungary, and the spilling of the tailing pond in Ajka
Chronic toxicity – refers to the adverse effects seen after a long-term exposure to the
low-moderate level of chemical substance. E.g. some lakes in the Lake District are
enriched with nutrients, whereby it comes from agricultural runoff and sewage,
which has had a negative impact on the biological composition of those lakes
Factors influencing toxicity
Species – certain types of species are highly tolerant or intolerant to environmental
pollutions
Gender
Age – the young and the old are particular prone to environmental pollution
Nutrition – low nutrient diet can make one to be unhealthy, and so become more
prone to the impact of environmental pollution
Effects of environmental pollution
In terms of humans, environmental
pollution can affect many organs and tissues: liver, kidneys, immune system, skin,
central nervous system and lungs, as well as cognitive development
High level of pesticides sprayed in the air onto crops, will affect the cognitive
development of children. A study was done in America
Bio- key terms
Bioavailability – refers to the proportion of a substance that enter the organism and
have a simulated effect
Bioaccumulation – refers to pollutants being in a higher concentrates/level in the
body of an organism than in the environment
, Biomagnification – refers to pollutant becoming progressively higher concentrations,
as it moves through the food web
Persistent, Bioaccumulate and Toxic (PBT) chemicals
PBT is the worst type of pollutant as it stays around for a while and accumulate so
the toxicity of the concentration becomes higher
Therefore, there’s great concern over the impact of PBT chemicals
There’s much PBT:
- Organic PBT’s – polychlorinated chemicals and pesticide
- Inorganic PBT’S – metals
Risk Assessment
Risk assessments are carried out to decide what’s safe and not
The factors considered includes:
- The scope of the effect, e.g. skin, lung, cognitive development or all, so is the scope
wide-ranging
- The likeliness of the adverse effect
- The trend of the specified pollutant, e.g. is it getting worse (linear and exponential
increase)
- The trend of other stresses, as a change in the environment can cause more
exposure to another pollutant
- The recovery time, e.g. a pollutant may occur frequently, but the recovery time may
be quick, or it comes once in a while, but the recovery time takes a long time or
never
Chemical risk assessment
Risk refers to the probability of suffering harm from a hazard
It’s only a risk if one is exposed to the hazard
The chemical risk assessment is a process that systematically examines the nature
and magnitude of a particular risk to a particular chemical
The risk characterisation:
- Hazard identification – how is the chemical hazardous (e.g. via skin or inhaling)
- Dose-response (dose-effect) – how much of the chemical substance is needed have a
negative impact. This is often done with lab test with animals and a reference dose is
developed to find out the dose-response (to see what level is still safe for humans)
- Exposure assessment – how one become expose to the chemical substance source
(e.g. water or water), and how one become exposed to the chemical substance - so
the route in which one become exposed (e.g. drinking or inhaling), and where is the
most highly exposed population
In the end, the risk manager, such as the organisation of Environment Agency and
World Health Organisation, decides how to lower the risk after being given the
information
The risk management tools for lowering the risk include:
- Implementing law and regulations
, - Use new technology
- Education
Week 1 – Introduction
Definition of pollution – any substance introduced into the environment which
adversely affects the usefulness of a resource, as well as adversely impacting human
health and the ecosystems/natural environment
The type of pollutant substances (many substances can be pollutant, it mainly
depends on the amount, which will drive the impact):
- Natural – organic chemical = e.g. oil, inorganic chemicals = e.g. metals (mercury)
- Anthropogenic – organic chemical = e.g. pesticides
Pollutant – mobile
Pollutants discharged into the atmosphere are carried by the wind, which is one of
the key ways in which pollutants are transported away from the source and across
boundaries, e.g. all the way to the poles
Another key way in which pollutant is transported is via the hydrological cycle,
through the flow of water at the surface or in the ground. Lakes are the key congilate
for moving pollutant from the terrestrial zone to the fluvial environment (water
environment). Water sources, like aquifers, can become contaminated because
urban areas can introduce pollutants which get transported below ground in the
aquifer. The polluted aquifer may then get upwelled to the surface somewhere far
away through wells
Furthermore, the artificial drainage of polluted water via pipes, as it moves and
discharge the pollutant to the environment. E.g. sewage
Moreover, the ocean can become contaminated by pollutant due to accidents or
intentional introduction through dumping
Pollutant – change form
Pollutant can change into different substances as it evolves, it can become toxic, in
which there are multiple drivers that underpin the change
The physical breakdown, chemical or biological reaction can change the form of the
pollutant
The changes in which the pollutant undergo can change the toxicity of the substance
– its relative impact on humans and the environment
Microbes can remove and control pollutants, as it can break them down, through
bioremediation (introducing microorganisms to consume and breakdown
pollutants). In order to improve the environment which was once polluted
Pollution extremes
There’s different levels of pollution extreme:
- Some are very obvious (visible) and cause devastations, such as big accidents
whereby the impact is very well-known
- However, there are pollutions that’s less obvious (it’s invisible, odourless and
tasteless)
, Pollution impacts formula (PAT) = population x affluence x technology
Chemical toxicity
Pollution is concerning to the environment because it
toxic to the terrestrial and/or aquatic ecosystem and
human health
All substances are potentially toxic, whether it’s natural
or anthropogenic, but it’s underpinned by the dose. As
some pollutant only require a small dose to be highly
toxic, while other substances require high dosage to be
toxic, e.g. gold. So, the dose makes the poison
This is known as the dose-effect relationship
Acute and chronic toxicity
Acute toxicity – refers to the adverse effect seen soon after a one-time exposure to
the chemical substance. Acute toxicity usually occurs due to accidents, e.g. the
mining accident which released cyanide and other toxic metals to the Tiszar river in
Hungary, and the spilling of the tailing pond in Ajka
Chronic toxicity – refers to the adverse effects seen after a long-term exposure to the
low-moderate level of chemical substance. E.g. some lakes in the Lake District are
enriched with nutrients, whereby it comes from agricultural runoff and sewage,
which has had a negative impact on the biological composition of those lakes
Factors influencing toxicity
Species – certain types of species are highly tolerant or intolerant to environmental
pollutions
Gender
Age – the young and the old are particular prone to environmental pollution
Nutrition – low nutrient diet can make one to be unhealthy, and so become more
prone to the impact of environmental pollution
Effects of environmental pollution
In terms of humans, environmental
pollution can affect many organs and tissues: liver, kidneys, immune system, skin,
central nervous system and lungs, as well as cognitive development
High level of pesticides sprayed in the air onto crops, will affect the cognitive
development of children. A study was done in America
Bio- key terms
Bioavailability – refers to the proportion of a substance that enter the organism and
have a simulated effect
Bioaccumulation – refers to pollutants being in a higher concentrates/level in the
body of an organism than in the environment
, Biomagnification – refers to pollutant becoming progressively higher concentrations,
as it moves through the food web
Persistent, Bioaccumulate and Toxic (PBT) chemicals
PBT is the worst type of pollutant as it stays around for a while and accumulate so
the toxicity of the concentration becomes higher
Therefore, there’s great concern over the impact of PBT chemicals
There’s much PBT:
- Organic PBT’s – polychlorinated chemicals and pesticide
- Inorganic PBT’S – metals
Risk Assessment
Risk assessments are carried out to decide what’s safe and not
The factors considered includes:
- The scope of the effect, e.g. skin, lung, cognitive development or all, so is the scope
wide-ranging
- The likeliness of the adverse effect
- The trend of the specified pollutant, e.g. is it getting worse (linear and exponential
increase)
- The trend of other stresses, as a change in the environment can cause more
exposure to another pollutant
- The recovery time, e.g. a pollutant may occur frequently, but the recovery time may
be quick, or it comes once in a while, but the recovery time takes a long time or
never
Chemical risk assessment
Risk refers to the probability of suffering harm from a hazard
It’s only a risk if one is exposed to the hazard
The chemical risk assessment is a process that systematically examines the nature
and magnitude of a particular risk to a particular chemical
The risk characterisation:
- Hazard identification – how is the chemical hazardous (e.g. via skin or inhaling)
- Dose-response (dose-effect) – how much of the chemical substance is needed have a
negative impact. This is often done with lab test with animals and a reference dose is
developed to find out the dose-response (to see what level is still safe for humans)
- Exposure assessment – how one become expose to the chemical substance source
(e.g. water or water), and how one become exposed to the chemical substance - so
the route in which one become exposed (e.g. drinking or inhaling), and where is the
most highly exposed population
In the end, the risk manager, such as the organisation of Environment Agency and
World Health Organisation, decides how to lower the risk after being given the
information
The risk management tools for lowering the risk include:
- Implementing law and regulations
, - Use new technology
- Education
