Environmental Health Impact Assessment., Evaluation of a Ten-Step Model
Rainer Fehr
"Environmental impact assessment" denotes the attempt to predict and assess the impact of development projects on the environment. A component dealing specifically with human health is often called an "environmental health impact assessment." It is widely held that such impact assessment offers unique opportunities for the protection and promotion of human health. The following components were identified as key elements of an integrated environmental health impact assessment model: project analysis, analysis of status quo
(including regional analysis, population analysis, and background situation), prediction of impact (including prognosis of future pollution and prognosis of health impact), assessment of impact, recommendations, communication of results, and evaluation of the overall procedure. The concept was applied to a project of extending a waste disposal facility and to a city bypass highway project. Currently, the coverage of human health aspects in environmental impact assessment still tends to be incomplete, and public health departments often do not participate. Environmental health impact assessment as a tool for health protection and promotion is underutilized. It would be useful to achieve consensus on a comprehensive generic concept. An international initiative to improve the situation seems worth some consideration. (Epidemiology 1999;10:618625)
Keywords: impact, health impact assessment, environment impact assessment, environmental management, evaluation, health protection, health promotion.
Context
The term "environmental impact assessment" usually denotes the attempt to predict and assess the impact of development projects on the environment. First introduced as a formal procedure in the United States,' a variety of approaches now exists for public and private development projects worldwide, for example, approaches suggested by the
United Nations Environment Programme' and the World
Bank.3
In the European Union, environmental impact assessment is based on a European Council Directive4 that covers highways, train lines, airports, industrial plants, waste disposal facilities, and many other development projects. In article 3, the directive states: "The environmental impact assessment will identify, describe and assess ... the direct and indirect effects of a project on the following factors: human beings, fauna and flora, soil, water, air, climate and the landscape, the inter-action be-
From the Institute of Public Health for North Rhine-Westphalia and Depart, ment of Public Health, University of Bielefeld, Germany.
Address correspondence to: Rainer Fehr, Landesinstitut ffir den Offentlichen
Gesundheitsdienst NRW (LOEGD), P.O. Box 20 10 12, D-33548 Bielefeld,
Germany.
This project was funded by the German Federal Ministry of Research and
Technology (BMFT), grant no. 07PH1`0313.
© 1999 by Epidemiology Resources Inc.
618
tween the factors, . . . , material assets and the cultural heritage”4 (emphasis added). In Germany, environmental impact assessment was enacted by federal law in 1990.5
A component of environmental impact assessment dealing specifically with impact on human health is often called
"environmental health impact assessment" (EHIA). It is widely held that EHIA offers unique opportunities for the protection and promotion of human health.6,7 In the World
Health Organization (WHO) "Health for All" program, the target environmental health management calls for EHIA.8
Practical approaches to EHIA were described by WHO,7,9 the Asian Development Bank,10 the National Health and
Medical Research Council in Australia," and others.
At the University of Bielefeld, in cooperation with the
Institute of Public Health for North Rhine-West, phalia, a project on EHIA was performed, which aimed to improve the coverage of human health in the process of environmental impact assessment.12-16 The project included the following components: analysis of the status quo concerning EHIA, including the legal basis and existing approaches; survey of current practice and involvement of public health departments concerning EHIA; analysis of EHIA documents with respect to coverage of health aspects; comparison and evaluation of existing EHIA approaches; development of a
"generic" EHIA concept that would be broadly acceptable from scientific as well as from practical perspectives; deployment of quantitative risk assessment as a key methodology for EHIA; and evaluation of this concept in model applications.
Epidemiology September 1999, Vol. 10 No. 5
This paper summarizes selected project results. In particular, it describes the ten-step EHIA model, pres synopsis of the outcome of two major field applications, and presents selected conclusions.
Current Situation
As a foundation for an integrated concept, a number of existing approaches were identified, including "health and safety component of environmental impact assessment,”7
"environmental and health impact assessment," 9 "baseline risk assessment,"17 "effectvoorspelling" and
"gezondheitseffectrapportage" in The Netherlands,"18 "health aspects of environmental impact assessment" in Canada,19,20
"Public Health assessment,"21 "health risk assessment,"22 the
Australian "environmental and health impact assessment,"11 and New Zealand's "health impact assessment."23
The list includes prospective impact assessment in the stricter sense, for example, the approaches of WHO-Europe7 and the Australian approach,11 as well as generic quantitative risk assessment, such as the approaches of the
U.S. Environmental Protection Agency17 and the Agency for
Toxic Substances and Disease Registry.21 The approach22 of the California Air Pollution Control Officers Association seems to be unique in applying quantitative risk assessment prospectively to development projects.24
The current EHIA situation in Germany was examined by means of document analysis and postal survey. In an existing collection of environmental impact assessment documents, all documents dealing either with transportation or waste disposal projects were analyzed.25,26 This set contained 51
EIA documents concerning transportation, including 46 highway projects and 5 rail projects, as well as 20 documents concerning waste disposal, including 8 dump site projects, 10 incinerator projects, and 2 recycling plants. The document analysis was performed as a screening version for all documents and then as an in-depth version for a subset of documents. The screening analysis found limited or missing coverage of human health aspects in the majority of documents. The in-depth analysis confirmed a lack of systematic approaches. In summary, the coverage of human health aspects in the documents tended to be highly incomplete. To investigate the involvement of the Public Health
Service in prospective impact assessment, a survey was performed covering the local health departments in the state of North Rhine-Westphalia.13 From the total of 54 local departments, 46 (85%) responded to a questionnaire survey.
Three years after environmental impact assessment enactment in Germany, 41% of the departments had never participated in this procedure. The health departments were also asked about access to data regarding exposures and health effects. Whereas data on exposures to chemicals seemed often available, data on other exposures, for example, noise, and also on health effects were mostly missing. The need to receive EHIA training was widely accepted. Ninety-one per cent of the
HEALTH IMPACT ASSESSMENT 619 health departments expressed the need for training, especially in methods (87%), procedures (67%), and tools
(63%).
In summary, the survey showed the Public Health Service to be highly motivated to engage in EHIA. At the same time, because of the inherent complexity of EHIA, the survey demonstrated the need to provide guidance. The demand of a feasible procedure for inclusion into the "tool box" of local health departments became obvious and triggered the refinement of the integrated EHIA approach.
Integrated EHIA Approach
The following components were identified as key elements of an integrated EHIA model: (1) analysis of status quo, (2) prediction of impact, and (3) assessment of impact. In addition, there is a need for communication of the results and for evaluation of the overall procedure. On the basis of elements of several of the approaches mentioned above, a
"generic" EHIA concept was designed.12,13 With appropriate adjustments both for specific project types and to local situations, this concept is meant to be applicable to a wide range of development projects.
The model consists of 10 steps (Figure l), which build on each other. Project analysis is expected to cover both
620 Fehr Epidemiology September 1999, Vol. 10 No. 5
TABLE 1. Steps 1 and 2 of the Ten-Step Environmental Health Impact Asses sment, Illustrated by Two Applications
Extension of Waste Disposal Site City Bypass Road
1. Project analysis
• Project specification in qualitative and quantitative terms
• Expected emission of chemicals, odors, noise, microbes, and other hazards
2. Regional analysis Physiogeography, natural features Anthropogenic features, land use Study area(s)
§ Additional waste disposal area of 16.9 PPlanned city bypass road: seven routing variants hectares annually to receive 240,000 (length of 6,163-6,628 m), daily traffic flow of tons 10,000-28,000 vehicles
§ Complex physicochemical processes PAnticipated relief function of inner-city areas within waste site PEmission of benzene, soot, N02, CO, etc.
§ Discharge ofiases, fluids, dust, PEmission of noise and vibrations microbes, an fungi PInjury hazard from traffic crashes
§ Stack emission of inorganic and organic chemicals § (Un-)treated leachate
§ Truck-related emissions, including noise, injury hazard
§ Rural county of Hildesheim
§ Four villages in the vicinity of waste disposal site
§ Study area: hilly profile; dominant land use: agriculture; federal highway
(Autobahn) crossing the study area
PCity in the Northwestern part of the
Rhinelands
PStudy area A: mixture of agricultural use and residential area
PStudy area B: inner-city area, to be partially relieved from current traffic
N02 = nitrogen dioxide; CO, carbon monoxide. normal operation and accidental releases and aims at the characterization of expected hazards, including acute toxicity and carcinogenicity. Regional analysis refers to physiogeography, meteorology, natural features, and land use and includes a definition of the study area for further investigation. The population is described by size, age, gender, health status, and behavioral patterns, for example, food consumption patterns and hobby activities. In step 4, the background situation is characterized on the basis of the preceding three steps and on environmental monitoring of existing pollution.
Using analogies and dispersion modeling, the next step refers to prognosis of future pollution, including air, surface and ground water, soil, flora, and fauna. On this basis, prediction of health impacts is attempted. Obviously, this step (step 6) is a key component of the whole procedure. It consists of three interrelated components. First, there is a qualitative assessment of changes concerning neighborhood features and quality of life as well as citizen concerns. In accordance with common scientific reasoning, a distinction is then made between agents for which a "threshold" of exposure can be defined vs other agents without this feature.
Second, for threshold agents, predicted levels of chemical pollution and intensities of other agents, such as noise, are being compared to appropriate (for example, medium-specific) limit values. For these agents, the assessment is implied in the comparison of the predicted values vs limit values. As a third component, for nonthreshold agents, especially carcinogens, quantitative risk assessment is necessary, including all relevant pathways and agents. In addition to the quantitative estimate of risk, decisions are needed on "acceptable additional risk." A commonly used level is a risk of 10-5, ie, one additional lifetime cancer case per 100,000 persons exposed. In the next step, a summary assessment of the predicted health impacts is given.
On the basis of all the information of the preceding steps, recommendations are given concerning planning alternatives, emission control, monitoring, public information, postproject analysis, etc. Considering the complexity of the overall procedure, the numerous details of the methods and the range of assumptions involved, it is no easy task to communicate the results. EHIA demands special efforts to communicate the underlying assumptions, the resulting predictions, and the assessments correctly and efficiently to all parties involved, including planners, decision makers, and the public at large. Risk comparisons and visualization methods may be helpful in this respect.
Whenever one of the project alternatives that were scrutinized by EHIA is actually put into reality, the opportunity arises to evaluate EHIA methods and assumptions. This can be done by comparing the predicted impact to the actual situation, for example, by establishing specific monitoring procedures and continually evaluating the state of the environment as well as human exposures and health outcomes.
Field Applications
The ten-step model described above was first applied to the enlargement of an existing waste disposal facility in Lower
Saxony. Another model application refers to a highway planned in the City of Krefeld, North RhineWestphalia.
Regarding the planned extension of a nontoxic waste disposal site, 27 a task force on EHIA was formed, and the ten-step EHIA model approach was applied. Selected results of the first four EHIA steps are summarized in Tables
1 and 2. Even in the "common," nontoxic waste disposal site, complex physicochemical processes take place, depending on the waste composition, including solubility and volatility of components, on humidity, acidity, and temperature. These processes last for long time spans
(decades) beyond the filling phase of the disposal site. They strongly change over time and involve discharges of gases, dust, microbial contamination, and fluids (leachate). In the typical case, gases are colEpidemiology
September 1999, Vol. 10 No. 5 HEALTH IMPACT ASSESSMENT 621
TABLE 2. Steps 3 and 4 of the Ten-Step Environmental Health Impact Assessment, Illustrated by Two Applications
Extension of Waste Disposal Site City Bypass Road
3. Population analysis
§ Size, composition
§ Health status
§ Behavioral patterns
4. Background situation
§ Environmental monitoring
§ Existing pollution
§ Identification of additional data needs lected and incinerated, resulting in stack emissions composed of a variety of inorganic and (chlorinated) organic compounds. In addition, trucks delivering waste will travel to and from the waste disposal site, so traffic emissions (chemicals and noise), and traffic-related injuries also need to be considered.
The second EHIA application reported here refers to a planned major bypass road in the City of Krefeld.28
Because of a long-standing problem of traffic congestion within inner-city areas of Krefeld, plans were made to build a bypass road, relieving inner-city areas partially from traffic flows. The environmental impact assessment procedure for the bypass road took six different routes into consideration. Changes of traffic flow had been computed using two different planning scenarios, the first of which implied constant numbers of employees in the area, whereas the second scenario implied slightly increased numbers in future years. The environmental impact assessment had led to the recommendation of one specific route alternative (variant No. 6).
For the EHIA, we selected two of the route variants and added the "null" variant, ie, the option to build no additional city bypass road at all. These three variants were studied in both study area A, ie, the area potentially
TABLE 3. Step 5 of the Ten-Step Environmental Health
§ County population: 287,000
§ Study area population: 5,863
§ Vulnerable populations, indicated by two hospitals, four nursery schools (N = 144), three schools (N = 388), and playgrounds and sportsfields
§ Local food production, including gardening, fishing
§ Existing waste disposal site located on a hill, with one of the villages located downhill § Treated leachate currently discharged into creek that crosses a village and is tributary to river used for fishing
§ Elevated lead concentration in river sediment, probably from mining in the Han mountains § 14 documented sites of contaminated soil in the area No indication of existing relevant emissions, no outdoor air
§ City population: 248,000
§ In addition to vulnerable populations documented in the environmental impact assessment, a senior citizen home was identified § Traffic-related injuries in 1994: 66 cases in study area A and 65 cases in study area B, including 1 fatal case in each area
§ Emission from vehicles using the existing roads § Long-distance transmission from residential and industrial sources, including chemical industry and energy production
§ In study area B: several industrial emission sources
§ Telemetric outdoor air measurement station of statewide 'TEMES" system
§ Existing noise levels (day/night) according to noise control program (1992): elevated noise levels in several parts of study area B impacted by the new bypass road, and study area B, ie, the area potentially relieved from traffic. In both study areas, receptor points were defined for each routing variant.
Selected results of the first four steps of EHIA for this project are summarized in Tables 1 and 2, in a parallel way to those of the waste disposal project.
Results concerning the predicted changes of pollution levels and the health impacts are shown for both projects in Tables 3 and 4. For the extension of the waste disposal site, the prognosis of future pollution levels was based on extrapolations of measurements of current emissions from existing disposal fields, supplemented by data from the technical literature. "Receptor points" corresponding to the four villages in the study area were defined, and dilution factors were obtained from modeling results performed by an outside agency (TOV Hannover Sachsen, using the Miktoskaliges Klima- und Ausbreitungsmodell
(Microscale Climate and Dispersion Model). For all receptor points, the predicted air concentrations were below recognized limit values. It was calculated, however, that in a neighborhood close to the waste disposal site, 1,1-dichloroethane concentrations and hydrogen sulfide concentrations would surpass current limit values. Although these concentrations would
Impact Assessment, Illustrated by Two Applications
Extension of Waste Disposal Site City Bypass Road
5. Prognosis of future pollution levels
§ Prognosis of chemical and physical agents
§ Coverage of environmental media and food chain, where indicated NO2 = nitrogen dioxide.
* Modeling performed byTÜV Hannover Sachsen.
§ Gas discharges: selection of inorganic and organic chemicals, including a total of eight carcinogens
§ Model-based estimation of dilution factors* for four receptor points
§ Noise from trucks delivering waste
(assessed for 12 places): additional 3.2 db
(A) in 1 place (nonresidential
neighborhood);