2.12 Types of impacts
EnTA focuses on characterising potential impacts associated with
outcome categories, or endpoints. The outcome categories are: Human Health
Impacts, Local Natural Environment Impacts, Social and Cultural Impacts, Global
Impacts, and Resource Sustainability. The performance of each technology option
is evaluated using these broad categories.
Each outcome category aggregates a large amount of information
associated with the environmental consequences of a technology. This approach
provides a useful way to combine impacts so that different technological options
can be compared against common criteria. However, it must be acknowledged that
specific impacts of a technology intervention may not receive appropriately
detailed or balanced attention in such an approach. Moreover, there is no
simple, objective way to combine impacts.
While there are various schemes that attempt to assign relative
weights to individual impacts, thus allowing them to be subsequently aggregated
in a rational way, their somewhat complex and arbitrary nature make them
inappropriate for use in EnTA. One objective of an EnTA is to show if more
information-intensive and rigorous assessments, such as environmental risk
assessment and environmental impact assessment, are necessary and justified.
Such tools can provide a more rational way to aggregate impacts, resulting in
increased confidence in the assessment findings.
A description of each of the outcome categories, or endpoints,
is provided below.
Impacts involving human health and safety
This category focuses on the potential impacts of a technology
on the health, safety and well being of the community and workers. Impacts may
be associated with injury, discomfort or death. There are three main impact
pathways that need to be considered in the assessment of human health and
- Communicable Diseases - Vector borne diseases (e.g. malaria), sanitary
hygiene diseases, risk associated with handing of infectious wastes;
- Injury - Risk of accidents from traffic, explosions, falls, heat stress,
operation of machinery, handling of physically hazardous wastes and resources
(e.g. sharps), loss of hearing; and
- Exposure to hazardous chemicals - Inhalation (e.g. air pollution), dermal
contact, ingestion of contaminated food and water (e.g. pesticide residue) of
hazardous chemicals and of radioactive material.
The primary focus for this category normally involves
characterising the effects of chemical releases and other hazards associated
with the technology. When assessing the effect of chemicals three principal
questions should be asked:
- What is the toxicity or potential hazard associated with release?
- How much of this chemical is likely to be released either through normal
operational practices or as a consequence of spills and other accidents?
- How many people will likely be affected by the hazard?
Impacts on the local natural environment
This category focuses on the effects a technology may have on
organisms, their habitats, the life supporting capacity of natural ecosystems,
and on biodiversity. Of particular concern is the loss of endangered and rare
plant and animal species, and destruction of endangered and limited habitats.
Three principal impact pathways should be considered when assessing impacts in
- Habitat loss or alteration through land clearance (e.g. as a consequence of
raw material demand or development of a site);
- Physical disruption of habitat; for example, the construction of pipelines
that inhibit the migration of animals; and
- The chemical contamination of the environment through the release of wastes
that have a direct toxic effect on flora and fauna (e.g. pesticides) or that
alter the functionality of an ecosystem through such processes as eutrophication
(e.g. the discharge of nutrients or other chemicals with high biological oxygen
demand (BOD)) and acidification.
Global environmental impacts
This category is concerned with the impact of the technology at
a global scale, typically as a cumulative impact. These impacts may or may not
be associated with a significant effect on a given local ecosystem or community.
Particular emphasis is placed on the release of substances that:
- Enhance global warming (i.e. greenhouse gases such as carbon dioxide,
methane and nitrous oxides); and those that
- Deplete the stratospheric ozone layer, for example chloroflurocarbons.
The significance of gaseous emissions with global warming or
ozone depleting potential varies with the chemical species, the amount released
and the time frame over which the impacts are considered.
Some technology interventions might also reduce the
effectiveness of carbon sinks, such as through the clearing of treed areas or
through soil degradation leading to the release of carbon into the atmosphere.
Impacts on scarce or non-renewable resources
This impact category relates to the effect that the technology
has upon the continued existence and availability of valued and scare resources.
There are two principal ways a technology can affect resource sustainability:
- By consuming a resource at a rate greater than it is replenished or greater
than the rate at which it may be continually supplied over the lifetime of the
- By contaminating a resource that is either used by the technology operators
or by other parties, but which has no direct link to the technology (e.g.
contamination of groundwater by an industrial manufacturing process).
When identifying and evaluating impacts on such resources it is
necessary to consider the relative scarcity of the resource, in both local and
regional or global terms, as well as the demands of the technology over its
lifetime (e.g. how much will be consumed or contaminated).
In general, three basic resource categories should be considered
in the assessment:
- Living Resources: Consumption or destruction of flora and fauna
resources such as crops, forests (e.g. tropical rainforests), and fisheries;
- Non-living resources: Mineral and chemical resources such as the
fossil fuels used in energy generation or the materials used in production, and
also the consumption or contamination of water resources; and
- Land resources: The land required by the industrial site, wastes, and
by supporting infrastructures and services which may reduce its potential for
To evaluate the significance of resource consumption it is
necessary to consider the future demands for the resource and how the technology
limits the potential for this resource to be used in the future. A technology
that uses recyclable materials and recycles wastes will generally have a lower
impact than a process that does not.
This category is related to the effects of a technology on a
community's values, social services and social cohesion. These impacts are in
addition to those related to human health, safety and well being. There are many
ways in which a technology may affect the social structure and well being of a
community, but the EnTA process will normally focus on three principal concerns:
- Cultural resources and values: Attention is directed towards the
effects a technology may have on sites or areas that have significant cultural,
religious, historical, scientific or other value to the community. Possible
pressures include the inappropriate use of a resource (e.g. the clearance of a
site leading to disruption of culturally valued ecosystems), or the potentially
detrimental effect that emissions may have on a resource (e.g. by way of acid
rain). When evaluating potential consequences, consideration should also be
given to visual, aesthetic and nuisance impacts. For example, an industrial
plant, or power lines, might be inappropriate in a landscape well known for its
historic or natural beauty, or the release of odourous compounds from an
industrial process might be unacceptable to the neighbouring community.
- Social disruption to the community: Included here are impacts that
may be associated with significant consequences for the social and economic
structure of the community. Important issues that might need to be considered
include the effect new workers (and their dependants) may have on the community,
the possible loss of livelihood through the over use of a resource (e.g.
fisheries), and the relocation of people as a result of a technology
- Equity issues: It is unlikely that impacts associated with a
technology will be equally distributed through the community - specific sections
of society may suffer disproportionately. In many instances the people most
affected are those without strong institutional support. Particular attention
should be paid to the potential effects of a technology development on
indigenous people, the poor, children and women.
Since many of these concerns will also be related to the heath
impacts and resource demands associated with the technology, it is appropriate
for this impact category to be the last to be examined.