Preamble
Environmental Impact Assessment (EIA) can be defined as the systematic
identification and evaluation of the potential impacts (effects) of proposed
projects, plans, programmes, or legislative actions relative to the
physico-chemical, biological, cultural, and socio-economic components of the
total environment”. The primary purpose of the EIA process, is to encourage the
consideration of the environment in planning and decision making and to
ultimately arrive at actions which are more environmentally compatible. The
first legislation on EIA started in 1969 in USA and was called as National
Environmental Policy Act (NEPA). This was rudimentary till 1970 and later every
State adopted it by 1973. Australia
closely followed in 1974. The Netherlands
and Japan
followed by 1981 and 1984, European Union by 1985. Subsequently all other
countries made it mandatory for their developmental programme. Nigeria enacted
after the Rio summit and brought out the EIA
by a Decree No.86 n 1992.
In the EIA process there are several
stages which include: Coverage of EIA (scooping), Preparation of EIA Report
(Environmental Impact Statement, EIS), Review of the report, Consultation and
participation, Synthesis of the findings of Consultation, Decision making, and
Monitoring and post-auditing. The emphasis, however should be laid on the EIA
and EIS.
EIA coverage includes Scoping, Baseline
study, Impact evaluation, Mitigation measures, Assessment (Comparison of
alternatives), and Documentation. Other steps are EIA review, Public
participation and Post auditing.
The EIA Study is mandatory for at least
19 project categories in Nigeria.
Health Impacts
“Human Environment” shall be interpreted
comprehensively to include the natural and physial environment and relationship
of people with the environment. This means that economic or social effects are
not intended by themselves to require
preparation of an EIS. When the EIS is prepared and economic or
social and natural or physical environmental effects are interrelated, then
the EIS will discuss all of these effects on the human environment. In the
socioeconomic environment (Social-impact Assessment, SIA), data should be
obtained on demographic concerns, economic and employment concerns, Land use,
Values, Taxes, housing, health, social services, education, and transportation. The SIA variables include: population
impacts, community/Institutional arrangements, conflicts between local
residents and newcomers, individual and family level impacts, and community
infrastructure needs.
The tasks involved in the HIA are:
·
Definition of project type and
location
·
Health hazard identification
(Physical, Chemical, Biological and Radiological, Exposure pathways, etc.)
·
Initial Health Examination (use
Health Status indicators, Morbidity indicators, Mortality indicators, Health
resource indicators, Health programme indicators)
·
Establishing the Requirement
for HIA
·
Terms of Reference (TOR)
definition for HIA
·
Health Impact Assessment
·
Health Risk Management, and
·
Benefit Monitoring and
Evaluation
A potential scale for rating health effects
is developed which will have a numerical rating between 0 and 8 with (-) sign
for negative effects and (+) sign for beneficial effects.
In most EIA studies, mitigation measures
for undesirable health effects and these may fall into; mitigation through
control of source, mitigation through health-services development, and
mitigation through health services development.
There can be selection of Proposed-Action
Alternatives whose objective is not to ‘carry out the selection process itself’
but ‘to assist the decision maker’. For this purpose the information has to be
organized giving adequate direction on the classification of health effects
that are significant (grouping into carcinogenic, teratogenic, mutagenic and
hereditary effects, organ-tissue effects, traumatic effects, and infection from
biological health-impact-causing agents), number of affected population,
assignment of rating for the effects, and evaluation of factors that are
affected differently for each alternative.
Preparation of Written Documentation
and Considerations
The voluminous data generated should be
summarized succinctly in the EIS. The most extensive material should be
presented as appendices and the external supporting data and literature should
be adequately referenced. Many impacts can be quantified using multiplier
factors. Logical bases for assessment, derived from institutional guidelines
can be used. Impact mitigation measures are often straightforward; however,
institutional capacity can be a limiting factor in implementing or selecting
mitigation options. It may be necessary to make tradeoffs between positive
socioeconomic impacts and negative natural environment impacts.
SOURCE
M.
K. C. Sridhar
Professor
of Environmental Health,
Faculty
of Public Health, College
of Medicine, University of Ibadan, Nigeria