Conducting Environmental Impact Assessment in Developing Countries (United Nations University, 1999, 375 p.): 9. Emerging developments in EIA: 9.5 Environmental health impact assessment: 9.5.2 Potential methodologies and approaches for addressing health impacts: 9.5.2.2 Integrate health impacts into EIA

Conducting Environmental Impact Assessment in Developing Countries (United Nations University, 1999, 375 p.)

9. Emerging developments in EIA

9.5 Environmental health impact assessment

9.5.2 Potential methodologies and approaches for addressing health impacts

		(introduction...)
		9.5.2.1 Adapt EIA study activities
		9.5.2.2 Integrate health impacts into EIA
		9.5.2.3 Use a targeted approach
		9.5.2.4 Probabilistic risk assessment

9.5.2.2 Integrate health impacts into EIA

Integrate an existing health impact methodology into the typical activities in an EIA study or use the health impact methodology as the focus of the EIA study. To serve as an example, a generic methodology for EHIA has been suggested by the WHO. It consists of the nine steps listed in Table 9.11. Steps 1 and 2 are related to the normal EIA process in which primary, secondary, and tertiary impacts on environmental parameters are assessed. Step 3 is derived from information given in the EIA and for which environmental health factors can be identified. Methods for identification of environmental health factors could be based on epidemiological and/or toxicological evidences of causal links between environmental parameters and health effects. Step 4 involves the study of exposure pathways. Steps 5 and 6 use epidemiological and toxicological information on dose-incidence and dose-response relationships between environmental parameters and specific health effects. Step 7 can be used to evaluate significance and acceptability of adverse health effects, and step 8 focuses on mitigation measures. Finally, step 9 involves appropriate decision-making. This generic EHIA methodology has been modified to allow its use for chemical manufacturing facilities.

Table 9.11 Steps in EHIA methodology

Item number	Steps to be taken	Tools to be used
Step 1	Assessments of primary impacts on environmental parameters	Regular impact assessments process
Step 2	Assessments of secondary and tertiary impacts on environmental parameters	Regular impact assessments process
Step 3	Screening of impacted environmental parameters of recognized health significance (EH factors)	Epidemiological knowledge
Step 4	Assessments of the magnitude of exposed population for each group of EH factors	Census, land use planning
Step 5	Assessments of the magnitude of risk groups included in each group of exposed population	Census
Step 6	Computation of predicted health impacts in terms of mortality and morbidity, if possible	Results from risk assessments studies
Step 7	Definition of acceptable risk (or of significance of adverse health impacts)	Assessments of trade off between human and economic requirements
Step 8	Identification of mitigation measures to prevent or reduce significant adverse health impacts	Abatement of EH factors? Magnitude reduction of exposure, reduction of exposed populations, protection of risk groups
Step 9	Final decision on whether or not the project should proceed

Source: Giroult, 1988, WHO Interest in EHIA, In: Wathern, P. (Ed.) Theory and Practice, Routledge: London.