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 Australia Netherlands Japan Nigeria 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.
ARTICLE SOURCE:
M. K. C. Sridhar
Professor of
Environmental Health,
Faculty of Public
Health, College
of Medicine University of Ibadan Ibadan