Environmental Impact Assessment (Human Health Effects)


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.
Text Box: EIA: Project Categories
Agriculture, Airport, Drainage and Irrigation, Land reclamation, Fisheries, Forestry, Housing, Industry, Infrastructure, Ports, Mining, Petroleum, Power generation and transmission, Quarries, Railways, Transportation, Resort and recreational development, Waste treatment and disposal and Water supply.
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.
M. K. C. Sridhar
Professor of Environmental Health,
Faculty of Public Health, College of Medicine, University of Ibadan, Nigeria
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