Comparative Risk Assessment and Environmental Decision Making

Comparative risk assessment (CRA) has become an increasingly accepted research tool and has helped to characterize environmental profiles and priorities on the regional and national level. Micro studies in comparative risk assessment are comparisons of interrelated risks involved in a specific policy choice (e.g. drinking water safety: chemical versus microbial disease risks) and focus often on one or a few types of environmental problem. At a larger scale are statewide or nationwide applications of CRA or programmatic CRA that consider multi-risks facing the society by comparing different types of environmental problems. This chapter reviews micro studies and macro applications of comparative risk assessment and then discusses future directions.

Decision-making in environmental projects is typically a complex and confusing exercise, characterized by trade-offs between socio-political, environmental, and economic impacts. Cost-benefit analyses are often used, occasionally in concert with comparative risk assessment, to choose between competing project alternatives. The selection of appropriate remedial and abatement policies for contaminated sites, land-use planning and other regulatory decision-making problems for contaminated sites involves multiple criteria such as cost, benefit, environmental impact, safety, and risk. Some of these criteria cannot easily be condensed into a monetary value, which complicates the integration problem inherent to making comparisons and trade-offs. Even if it were possible to convert criteria rankings into a common unit this approach would not always be desirable since stakeholder preferences may be lost in the process. Furthermore, environmental concerns often involve ethical and moral principles that may not be related to any economic use or value.

Considerable research in the area of multi criteria decision analysis (MCDA) has made available practical methods for applying scientific decision theoretical approaches to multi-criteria problems. However, these methods have not been formalized into a framework readily applicable to environmental projects dealing with contaminated and disturbed sites where risk assessment and stakeholder participation are of crucial concern. This paper presents a review of available literature on the application of MCDA in environmental projects. Based on this review, the paper develops a decision analytic framework specifically tailored to deal with decision making at contaminated sites.

Comparative risk assessment is usually performed to inform risk ranking and prioritization exercises. Here it is applied as an innovative tool for testing the scientific validity and reliability of a 2002 USEPA human health risk assessment of perchlorate. Dietary exposure to nitrate is compared with drinking water exposure to perchlorate; both chemicals act on the thyroid gland by iodide uptake inhibition (IUI). The analysis shows that dietary nitrate is predicted to cause orders of magnitude more IUI than perchlorate exposure at environmental concentrations. If the 2002 USEPA risk assessment is scientifically valid and reliable, then a generally accepted decade-old USEPA nitrate risk assessment is fatally flawed, and risk management decisions based on it are severely under-protective. If the nitrate risk assessment is valid and reliable, however, then the 2002 USEPA perchlorate risk assessment is fatally flawed, unreliable and should not be used as the basis for risk management. The origin of this inconsistency is a policy decision to deem IUI a “key event” that may lead to changes in thyroid hormones and consequent adverse effects. This implicitly treats IUI as “adverse”. Unless large and sustained over a long period, however, IUI is mundane, reversible, and arises at exposure levels orders of magnitude below true adverse effects. In communities where quantitative human health risk assessment is expensive or expertise is lacking, comparative exposure assessment provides a cost-effective means to evaluate the merits of such assessments before taking costly risk management actions.

Recycled materials, such as recovered materials from the transportation sector or secondary or by-product materials from the industrial, municipal, or mining sectors can be used as substitutes for natural materials in the construction of highway infrastructure. Trace metals in these recycled materials may leach out and contaminate the groundwater and soil posing a long-term environmental problem. Environmental risk assessments are necessary to evaluate which recycled material applications are acceptable. The first step for determining the environmental risk of using recycled materials is to characterize the source term. Estimates of contaminant release fluxes can then be used in a comparative risk assessment. This paper will give an example of a comparative, probabilistic approach for exposure assessment. Existing deterministic models for estimating contaminant release will be presented and incorporation of variability in these models will be discussed.

An environmental risk assessment, uncommon since focusing only on the pollution risk of soil and groundwater through pesticides, for a site in the Mid-Hills of Nepal will be introduced and discussed.

It will be shown, that model fits which have been developed for the three compounds Metalaxyl, Dimethoate and Fenvalerate, show satisfying results for the further application on risk assessment for the first two, as they account for the general trend of the transport mechanism. For the latter one, the applied model failed due to unidentified transport and degradation processes. Furthermore, the assessment profiles show phenomena in the data which cannot be explained with the applied model, i.e. higher concentrations of pesticides in greater depths than in medium depths. Field studies conducted as combined tracing experiments with the respective pesticides and Vitasin Blue FCF 90 and Deuterium (as a conservative tracer) are used to investigate these phenomena. Results show a leading role of preferential flow paths and free soil water in the transport of pesticides into the deeper soil and into the groundwater system under the given agricultural system (ponding and furrow irrigation), climate and soil type. These additional field studies were necessary in order to reach a sound environmental risk assessment.

Unsafe water is a leadingcause of death and disease in economically disadvantaged societies. The development of centralized large-scale water treatment and supply systems has proven to be a slow, expensive strategy to provide safe drinking water in many low-income countries. Governments and non-governmental organizations have therefore increasingly been promoting point-of-use water treatment technologies in communities without reliable municipal water supplies. These technologies aim to be low-cost sustainable solutions that rely on filtration, disinfection and safe storage to improve source water quality. This paper uses a comparative risk assessment methodology to quantify the health and water quality impact of a point-of-use water treatment program being implemented in rural Haiti by a non-governmental organization. An observational study was used to measure diarrhea incidence in 120 families in the village of Dumay in Haiti. Univariate and multivariate statistical methods were used to (i) quantify the impact of the water treatment system in reducing the incidence of diarrhea, controlling for socio-economic differences in the population, and (ii) study the interaction of socio-economic factors and source water quality with filter use in diarrhea reduction. As part of the water quality impact assessment study, the microbial content of source water and stored water in intervention and non-intervention households was measured using membrane filtration tests. The comparative risk approach used in this study is designed to provide insights and inputs into environmental decision-making issues relating to resource allocation between competing gastro-intestinal disease reduction initiatives such as point-of-use water treatment systems, high-quality source water development projects, and household safe storage mechanisms.

During past decades, several million tons of aluminum industry wastes have been dumped, without a bottom lining system, right on the shore of the Danube River in northwest Hungary. The resulting red sludge ponds pose two major threats to the environment: drinking water resources could be polluted by infiltration, and wind erosion contaminated surrounding residential areas. Due to limited resources, the latter issue was not addressed until the present owner and operator of the industrial site took charge.. To solve the problem of cost, the operator applied treated hazardous waste to form a surface cover for the already polluted site. His proposal to he use this technology at the site obtained all the necessary permissions for implementation. Due to a new piece of national regulation, risk-based evaluation of the remediation technology became required. The task of the risk assessment was to compare the original (uncovered) state of the site and its human health risk to the remediated (covered) situation, where the covering layer consisted of manipulated hazardous waste material. This interesting case study of risk analysis, beside its challenge to the assessor’s expertise, raised several questions regarding environmental ethics, environmental stewardship, and responsibilities.

Experience is a great teacher, and learning from someone else’s experience can make the lessons much less painful. This chapter shares lessons learned from the recently completed New Jersey Comparative Risk Project (NJCRP). It briefly describes the project and offers a preliminary evaluation of its adequacy, value, effectiveness, and legitimacy. The main purpose of this broadly scoped project was to inform a state regulatory agency’s strategic decisions. The project involved a large number of technical experts from a variety of fields, plus public officials, high-profile stakeholders, and members of the general public over a four-year period. It gathered and organized a vast amount of useful information, but found that there was still an inadequate scientific basis for a precise single ranking of environmental threats. The NJCRP instead developed policy findings using a humbler approach that involved less aggregation. Highlighted environmental threats for New Jersey included land use change, indoor environmental problems, a set of traditionally regulated pollutants, and invasive exotic species.

Comparative risk assessment is a natural tool for decision making regarding transboundary environmental issues. A workgroup of environmental experts met during the NATO Workshop over three days and addressed the state of the practice of comparative risk assessment and its applicability in an international context. Discussion of the application of comparative risk assessment led to a proposed case study on transboundary risks from pesticide use. Pesticides are of international concern because of transboundary trade of agricultural goods, impacts of applied pesticides on international environmental resources such as water bodies, differences in local and national safety practices, and concerns over the transferability of assessment models developed under different conditions than where pesticides are ultimately applied. Thus, a comparative assessment of potential impacts of pesticides on an international scale is proposed to be illustrative of the utility of the methodology for international environmental policy purposes. Workgroup discussions included the need to defining terminology, data needs, methods and tools for comparing risks, development of evaluation criteria, key issues regarding transboundary comparisons, and unique communication issues for international collaboration. A proposal for future work, including recommendations for international risk comparisons are also offered.

A formulation for the value of information for conflict resolution is shown to provide insights and guidance for identifying the attributes of scientific procedures and studies needed to support participatoryrisk assessment and decision making. Traditional approaches to the value of information are first reviewed, including the determination of potential reductions in the uncertainty variance of risk-model outputs resulting from a proposed study or data collection program, and the economic value of information in a decision-analytic context. Limitations of these metrics are identified — when scientific assessments are conducted by multiple experts who may be exposed to either consistent or inconsistent observations, and when decision value is required for multiple stakeholders who may differ in their prior beliefs, methods for interpreting scientific studies, and their economic valuations for the outcomes of alternative decisions. Methods for identifying the sources and implications of differences in these among experts and stakeholders are presented. The use of a precautionary ratio is proposed as a means for characterizing the source of differing degrees of precaution exhibited towards a proposed project by different rational stakeholders, highlighting the programmatic and scientific changes that could be considered by project proponents to attempt to build a consensus with other, more-precautionary parties. Initial methods for computing a monetary value of information for conflict resolution are also presented.

In this paper, we present a simultaneous equations model that provides a computationally efficient framework for computing long term, policy-dependent projections of global climate change. As part of our formulation, we explore the dynamic properties and numerical stability of the coupled system. We illustrate the framework with a numerical casestudy that utilizes the coupled system to compute projections of global-mean surface temperature change for three global carbon emissions control strategies. As part of our analysis, we explore the system’s sensitivity to changes in the numerical specification of two key scientific uncertainties concerning the global climate system.

Agencies and organizations charged with priority setting require analytical approaches that are accurate, efficient, and reliable. Increasingly, decision analysis is applied using formal techniques that are measurable and repeatable. This paper surveys available methods ranging from expert judgment approaches to complex statistical models, and considers the benefits and issues raised for decision making that applies various approaches.

A pathological debate has evolved on the appropriate role of risk analysis at the federal level in the US. On one hand, substantial academic, public and private sector efforts have developed techniques and justifications for incorporating risk analytical information into “risk rationalizing” decisions. At the same time, a normative critique has jelled around the inadequacy of risk analysis methods to fully describe, and thus to compare, risks (the “holistic” complaint) and the exclusive nature of the risk assessment process (the “anti-democratic” complaint). The past decade has also seen another substantial trend in risk analysis research: improved understanding, description and management of uncertainty. Unfortunately, inadequate attention has been given to merging the normative and technical trends. This has led to several undesirable consequences in the US, Europe, and other developed countries, consequences that include the potential for systematically arbitrary decisions, undermined credibility of risk analysis as a decision input, and pathological debate about the appropriate role of risk information in the risk regulatory debate. This suggests some lessons for developing countries as they adopt risk analytical methods, and undertake risk comparison exercises. In particular, careful attention to uncertainties and the technical debate may provide an opportunity to broach the current normative stalemate in countries that rely extensively on risk data, and to avoid that stalemate in developing countries.

Site specific ecological risk assessments (EcoRAs) can be improved in terms of technical relevance and managerial utility through the use of spatially-explicit exposure assessment. Formalized descriptions of landscape features (e.g., vegetation cover and physical components of an area) have been used to relate landscape features to the quality of habitat for particular wildlife species. Animals adjust foraging routes and alter daily use patterns in relation to spatial patterns within their home range. The quality of the habitat therefore influences a continuum of wildlife responses including presence-absence, carrying capacity, and dietary exposure to environmental constituents. This chapter describes an approach and a software prototype for combining expressions of habitat quality into spatially explicit risk assessment of contaminated terrestrial ecosystems. The approach and the software are intended for use as a part of a risk-based decision protocol to support the assessment of ecological value and site reuse options.

Although occurrence of disasters cannot be prevented completely, it is possible to minimize their hazards by taking precautions and applying effective emergency response plans. In addition to measures taken to reduce economical and human losses, an environmental dimension is required in these plans to control environmental pollution and lessen possible adverse effects on both ecosystems and human health, which in the long term may cost much more than direct disaster losses. Technological accidents triggered by natural disasters are one of the most important factors increasing the environmental damage. Therefore, it is of utmost importance to prepare regional plans considering both natural and technological disasters and aiming the coordination and resource sharing between the related authorities, institutions and factories. Geographical Information Systems (GIS) are powerful tools having comprehensive data query, analysis, and visualization capabilities, and they may facilitate preparation of such emergency plans. In this paper, the role of GIS in emergency response plans is explained. A case study from Turkey utilizing GIS extensively for regional environmental emergency planning is given and problems that can be faced in developing countries are discussed.

Two main criteria are usually taken into consideration for engineering water resources management, namely technical reliability and economic efficiency (techno-economic approach). To obtain sustainability, one should consider not only technical and economic issues, but also environmental and social aspects. In this paper it is explained how integrated risk analysis considering risk indexes in four dimensions (technical, economical, environmental and social) can be used in order to quantify the degree of sustainability in water resources management.

Industrial risk analysis suffers from many problems of uncertainty due to the difficulty of estimating various parameters of concern for the analysis. In the real world, we usually use many qualitative and/or uncertain parameters for risk evaluation. While the quantification of parameters is an important task, it is usually practiced according to the experience of the analyst (discrete approach) or by using probabilistic models (probabilistic approach). The discrete approach is very limited because it does not take into account the variability or the uncertainty of parameters. On the other hand, the probabilistic approach requires knowledge of the parameter’s statistical distribution, which may be very difficult or even impossible. Furthermore, in both approaches, qualitative variables are not easy to deal with. Over years of research, we have developed a general approach to overcome these problems. The estimation of parameters and the treatment of available data are based upon fuzzy logic models, with some improvements in the fuzzy reasoning mechanism. This paper presents a comparison between our fuzzy approach and the discrete and probabilistic approaches. A geotechnical application was developed to evaluate the risk of natural ground movements in a rock cliff that would have severe impact on the surrounding environment. We have ended up with a general approach to the problem of uncertainty and with some recommendations on how to approach different parameters according to their nature (using either the discrete, probabilistic or fuzzy method). The improvements we have made to the fuzzy reasoning process (beta cuts reasoning technique) has been approved by specialists in the domain of fuzzy logic and are applicable to all branches of science.

Management of municipal solid waste sites, toxic liquid waste sites, and former military and industrial contaminated sites is a pressing problem for most urban areas. In most cases these sites require management decisions when planning and instituting redevelopment. Very often decision-making is necessary for one of two cases: development of a new project on a contaminated site, or site conservation. Space limitations, health of local populations, preservation of historic sites — these urban area factors impose significant restrictions on the decision-making process. This present paper will discuss a quantitative analytical method that can be implemented for both Comparative Risk Assessment (CRA) and Environmental Impact Assessment (EIA) of development and reconstruction projects at urban contaminated sites. This method was implemented for several projects in St. Petersburg, Russia, including a CRA for a new underground development on a downtown city site contaminated by petroleum products.

Management of dredged contaminated sediments can be a contentious, difficult, and expensive task. Because the waterways from which sediments are dredged have multiple uses, competing interests are often brought to bear on any decision. No single best alternative is likely to emerge; different stakeholder groups will prefer different alternatives. This chapter investigates the utility of multicriteria decision analysis (MCDA) as a tool for incorporating stakeholder values into the decision process, for soliciting public participation, and analyzing novel technological alternatives. An outranking method called PROMETHEE is employed for three reasons. First, the emphasis placed on assessing new technologies — and especially beneficial reuse technologies — requires a method that facilitates introduction of new alternatives at any point during the analysis. Second, outranking methods are conducive to elucidating the contrasting value structures of different stakeholder groups. Third, they are more capable of handling semiquantitative scales (e.g., high, middle, low) than optimization methods such as MAUT or AHP. To illustrate the decision process under development, this chapter presents the results of a case study example involving stakeholders in Dover, New Hampshire concerned with the dredging of the Cocheco River.

Comparative risk assessment (CRA) is an important environmental decision-making tool, often used to identify broad risk categories and high priority risks. This chapter addresses some of the challenges that analysts and risk practitioners face in using CRA to promote scientifically sound decisions about environmental priorities. We argue that in order to meaningfully inform the decision-making process, analysts must give serious consideration to the decision context, and they must carefully tailor their messages, with a view towards clarity and balance.

Water in sufficient quantity and of adequate quality is necessary for the well-being of all living organisms. The importance and intensive use of fresh water makes it a vulnerable and increasingly limited resource. A wide range of human activities may lead to environmental deterioration of surface and ground water, either directly or indirectly.

In arid and semi arid regions, water resources management issue turns to be more imperative and necessary due to the scarcity of water resources and the irregularities of water flows in time and space. Deteriorating water quality is a particular threat in countries with scare water resources.

As far as Egypt is concerned, adequate supplies of fresh water is critical to the long term, sustained growth and development. Historically, water resources management focused on reallocating water to when and where it was required, a supply-side approach. In recent years, it has become increasingly apparent that the quality of available water is as important as the quantity. Poor water quality can render available supplies unsuitable for its intended uses. Thus, water quality, if not adequately managed, can serve as a serious limiting factor to the future economic development and to the public health and the environment which will result in enormous long term costs to the society. This in turn could lead to irreversible damage to the quantity and quality of available water resources. Thus, the need for better management of the quality of water resources is greatly recognized.

Recently, water quality issues have received high attention in the overall water resources planning and polices in Egypt. A water quality management program, with a national perspective was developed and implemented, which is based on an integrated approach to water quality data collection, analysis, interpretation, management and coordination. This program will provide a strong scientific basis for sound policy development and decision-making and assist in the development of strategies to reduce current and avoid future water quality problems.

In this context, the paper examines the main aspects and problems concerned with water quality deterioration in Egypt along with its environmental impacts and constraints to sustainable development. The importance and role of monitoring, data management, technology transfer, institutional strengthening, collaboration between ministries and stakeholders and sound financial framework are examined. The efforts exerted by the Ministry of Water Resources and Irrigation for better water quality management are highlighted. Finally, the challenges and benchmarks that decision makers have to face and deal with, for future actions are briefly outlined.

The agricultural chemicals commonly labeled as pesticides are perhaps the largest group of poisonous substances being intentionally disseminated throughout the environment. For some pesticides neither health nor environmental risk evaluations are available. Therefore, at the moment the prevention of occupational and environmental consequences of pesticide use may only be achieved if methodologies and threshold environmental values are developed for the assessment of risk to the individual due to handling pesticides. Pre-marketing preventive actions are the primary responsibility of industry and the public health and governmental authorities. These include discovering the toxicological properties of each pesticide (hazard identification), determine the dose-response relationship (No Observed Effect Level, or NOEL, identification), assessing or predicting the exposure level in the various exposure scenarios; and characterizing the risk. Post-marketing preventive activities consist of the promotion of proper risk management at the workplace. Such management includes the safety assessment of the specific conditions of use, the adoption of proper work practices, and assessment of background exposure, cultural and life-style factors, and bio-markers of specific susceptibility. Such bio-markers including semen quality assessment and biochemical markers of exposure, serum uric acid, urea, creatinine, bilirubin, aspartate amino transferase (AST), and Glutamic Pyruvic Transaminase (ALT). In a case study (Kafr El-Sheikh Governorate, Egypt), involving 240 different individuals, reduction in semen quality in the pesticide applicators (PA) was seen compared with none farm workers (NFW). Also, biochemical markers, uric acid, urea, creatinine and AST in PA were near the upper limit values of normal. The monitoring and surveillance of pesticide exposures is mainly suggested by the established concept of the reference value and related analytical procedures. This concept is an essential contribution to an objective discussion of risk with regard to individual stress and strain profiles in environmental exposure scenarios.

The impact of gaseous CO2 and SO2 attains additional importance when examining the processes of alteration and decay in historical buildings made of calcareous stones. We selected the Al-Ghuri complex (Cairo, Egypt) for the study of black crust formation on stone building surfaces due to the presence of carbonaceous materials and sulfatation via CaCO3 conversion to gypsum (CaSO4.2H2O). Under dry deposition, the breakdown of calcareous stones depends on the relative humidity and the presence of catalysts, e.g., O3 and oxides of Cu, Fe and Mn.

Depth profile analyses indicated the presence of sulfates to depths of 100 to 1200μm below the stone surface. Sulfatation was usually formed on the stone surface, and sometimes penetrated the outer surface through micro-fractures and pores. NaCl crystals (in cubic form) were precipitated at stone surfaces and pores due to the presence of sewage water via capillary action. Polyhalite [K

2

Ca

2

Mg(SO

4

)4.2H

2

O] and epsomite (MgSO

4

.7H

2

O) were developed as minute crystals up to 12μm.

This study reveals the influence of sulfatation and salt formation and microrganismal activities on accelerating the rate of monumental stone degradation. Such processes involve reaction of stone with the pollutants, transformation of CaCO

3

to CaSO

4

.2H

2

O, and precipitation of NaCl, which under appropriate conditions crystallizes within pores and micro-cavities of stones. One possible consequence is the rupture and spilling of the upper surface of the stone due to crystal pressure.

Population growth increases the output of sewage, which must be treated and discarded. Agricultural reuse can function as wastewater disposal, and simultaneously convert an environmental threat to a benefit, i.e., the supply of irrigation water to agriculture. Both quantity and quality aspects should be considered when irrigating with treated effluents, since its constituents may affect crops and groundwater. In this paper we refer to nutrients, represented by nitrogen or nitrates (NO

3

), and salinity, represented by EC (electrical conductivity) or chlorides (Cl). The levels of these constituents in wastewater are usually elevated; therefore, they may affect crops, soil structure, or groundwater quality. Combining wastewater treatment and desalination processes to maintain groundwater quality can diminish these impacts and prevent environmental deterioration. We have assessed the environmental impacts of wastewater irrigation by focusing on nitrate and chloride constituents. To that end, we developed an economic-hydrological model that incorporates various watersources and treatment processes in order to analyze the accelerated contamination of groundwater.

•

At present risk management is being used in different levels, support in advancing risk management is needed.

•

Risk management is an important tool in the assessment and management of environmental issues such as water quality, air quality, waste management

•

The planned development in the economic sectors ensuring sustainable development requires risk management tools to be imbedded in decision making.

•

To be able to move forward with risk assessment at decision making level, special training and awareness is needed. The use of IT should also be enhanced alongside.

We have developed mathematical models that describe radiation-induced mortality dynamics for homogeneous and nonhomogeneous (in radiosensitivity) mammalian populations. These models relate statistical biometric functions with statistical and dynamic characteristics of a critical body system in specimens belonging to these populations. The model of mortality for the nonhomogeneous population involves two types of distributions, the normal and the log-normal, for its specimens with respect to the index of radiosensitivity for critical system cells.

The mortality model for the homogeneous population quantitatively reproduces the mortality rate of laboratory mice chronically irradiated at low dose rates when the hematopoietic system (specifically, the thrombocytopoiesis) is the critical one. Comparison of the results obtained within the framework of the mortality models for homogeneous and nonhomogeneous populations show that the mortality model for the nonhomogeneous population predicts a higher mortality rate and a lower survival than would have been predicted from the averaged values of the radiosensitivity index of the critical system cells. The level of chronic dose rates presenting a hazard to nonhomogeneous mammalian populations becomes lower as the variance of their radiosensitivity indices become greater. For individuals possessing hyperradiosensitive critical system cells, even low-level irradiation can lead to mortality. These modeling results demonstrate the importance of taking into account the variability of individual radiosensitivity when predicting the mortality of mammals exposed to low-level irradiation.

These models of radiation-induced mortality, as well as the approaches suggested in the course of their elaboration, outline new pathways in the development of radiation risk assessment methodology. Additionally, the same methodology produces other useful information: a criterion is established that elucidates the groups of radiation risk among population residing in areas with elevated radiation background and among persons subjected to occupational irradiation. (Only routine blood sampling is necessary.) Applying the complete set of preventive and protective measures to persons revealed enables one to reduce the radiation risk both for the individuals and for the population as a whole.

Technogenic risks in Ukraine may exceed those in other countries. Besides, the largest technogenic catastrophe in the world occurred in Ukraine—the Chernobyl disaster.. Therefore, the estimation of endogenic and exogenic risk is extremely important, and not just for Ukraine. Our calculations were conducted using modified Gomperca-Meykema models developed by Russian scientists [2]. This work describes the major results of our quantitative estimation of the exogenic (i.e., external, unconnected with internal biological causes) and endogenic (i.e., caused by biological and/or genetic factors) risks of death, or predicted death rate of the Ukrainian population.

In the East and West alike, the transfer of former military bases to civilian hands creates challenges for those responsible for redevelopment. The former Warsaw Pact countries and former Soviet Union Republics countries have great difficulties solving the environmental problems that these lands present. The negative effect of military activities on the environment is far from uniform in different military areas. These differences have been determined mainly by the kind of military activity conducted in a particular area, as well as by the individual characteristics of the local natural environment. This report reviews our experience in research on the impact of military activities on the environments of both former and working military sites; environmental risk prevention and control; the Lithuanian experience in environmental management and evaluation of military lands; and ways to address environmental risk reduction, reuse, and renovation of damaged military territories.

After the diffusion from the Icmesa plant of the toxic cloud on 10

th

July 1976, there was a mobilization of the Public Authorities and the Italian Scientific organizations, especially the ones in Lombardy. Among the committees that were created during the emergency, one can mention the followings: for Reclaiming, for the Chemical (and Statistical) Analysis, for Research, for Epidemiology, Toxicology etc., etc.

The task of fixing acceptable limits, that is, of establishing the first“Risk Assessment” for TCDD in the soil in the Brianza area of Seveso, was carried out by Technicians and Scientists of several committees, with the constant supervision of the Regional Authorities and the cooperation of the Istituto Superiore di Sanità — I.S.S. — of Rome (National Health Institute).

The basic criteria were simple:

a)

NOEL (no observed effects level) on the most sensitive animal, that is the guinea pig:

b)

1 ng/Kg-body weight per day; Uncertainty factor: 1000;

c)

Inhabitants most exposed to risk (of ingestion of contaminated soil): children;

d)

Limit dose found: 1 pg/kg-body weight per day (equal to approx. 0, 14 gr. of soil ingested by a child weighing 20 kg, or 0,50 gr. for an adult weighing 70kg.);

From the above criteria, the acceptable amounts on the various matrixes were assessed: land, inside of housing, equipment and others as listed in the text of the Regional Law for Seveso. The defining of the risk areas was thus carried out taking into account only the contaminations found in the soil and measured on couples of samples (carrots), extracted by means of steel cylinders having a diam. of 7 cm and penetrating into the soil for about 7 cm.

From then onwards and for all operations relative to the reclaiming and rechecking, reference was made to the unit μg/m

2

, always intending a square surface of soil having 1 meter long sides and 7 cm deep. The conversion from μg/m

2

to the most commonly accepted ppt (weight of contaminating agent by weight of soil) is obtained to a good approximation by multiplying the number of μg/m

2

by factor 8 and therefore: Agricultural land — limit by law 0,75 μg/m

2

=6 ppt Non agricultural land — limit by law 5.00 μg/m

2

=40 ppt Limit for evacuating population 50.00 μg/m

2

=−400 ppt

It is surprising to note the difference between the Regional limit in Lombardy for evacuation especially considering all the economic and social consequences deriving from such action, and the limit “of concern” — but not yet of intervention — indicated by the Sanitary Control Authority of the United States (Center for Disease Control), which is 1 ppb=1000 ppt, that is 2,5 times higher than that adopted in Seveso: a different risk assessment of the presence of TCDD in the environment. The roads of Times Beach (MO) which had been sprayed with contaminated oils, were covered with a layer of asphalt to avoid contact with a contaminations of 300 ppb. Times Beach was (gradually) evacuated after the river had flooded the area and some analyses had shown the intensity of TCDD contamination.

In 1982 and in 1984/85, during the Seveso reclaiming, the “B” zone was also re-checked — this area has a contamination between 5 and 50 μg/m

2

— and confirmation of the unequal trend of the contamination was obtained, as tough the cloud had “bounced” on the land various times, leaving a toxic print less and less marked every time. Among such contaminated spots, the cloud left lower levels of TCDD (see the tridimensional representation). Therefore it was necessary to carry out a more detailed “risk assessment” than the one initially carried out 9 years before during the emergency period, taking into account the population at risk (approx. 6000 people) residing in the “B” zone.

In the document elaborated by the participants to the sub-committee of the “Cimmino” Committee for Seveso, organized by the Special office of the Lombardy Region and by I.S.S., in the meeting held in Milan on 26–30/03/84, it was shown that a daily ingestion of TCDD of 0.280 pg/Kg of body weight, increases the risk of cancer by 1/100.000, if we consider for the calculation, the effects observed on the liver of female rats. In fact the liver of female rats were considered to be the most sensitive organ to the toxic compound.

Moreover, it was assumed that the correlation between the risk of cancer and the dose of TCDD is linear. So, 0.028 pg/Kg-body weight per day reduce the risk to 1

*

10

−6

, while 2.8 pg/Kg increase it to 1

*

10

−4

and so on.

The contamination of Zone “B” was schematically assumed as follows: for 80% of its extension: 1.5 μg/m

2

=12 ppt of TCDD in the soil. The remaining 20% with 10 times higher contamination. The means of exposure considered are:

1.0

Ingestion;

2.0

Contact with the soil (cutaneous absorption);

3.0

Consumption of epigean and hypogean vegetables grown in the Zone “B” gardens.

4.0

Consumption of zootechnical products (chickens and rabbits) from that area.

On the basis of a series of hypotheses, which were only partially verified, the following table may be obtained, assuming that total risk is given by the sum of the single exposure risks.

We owe Prof. Schlatter of the Swiss Federal Institute of Toxicology, a clear presentation of “Risk Assessment” by 2,3,7,8 TCDD at “Dioxin 85” held at the Bayreuth University in the fall of that year.

Having examined the ADI (Acceptable Daily Intake), set in 1–10 pg/Kg-body weight per day, Prof. Schlatter lists the results of the latest researches of his Institute:

a)

The amount accumulated in the human body is known;

b)

The isomers (12) having toxic relevance are known;

c)

The main origin of TCDD in man is known: the intake of animal fats;

d)

The half-life period of TCDD in the human body is known, and this thanks to the experiments carried out on himself by Dr. Poiger, assistant to Prof. Schlatter: 5–6 years, 80 times longer than that in laboratory animals.

The population of the industrial areas, where the fumes and ashes of the municipal waste incinerators fall, assume 16 pg/Kg-body weight per day of toxic equivalent dioxins, i.e. of the 12 isomers having toxicity equalized to that of 2,3,7,8 TCDD. In view of the above, the proposed limit for ADI is largely exceded and it is necessary to examine the problems, staring from the effects on the health of the populations exposed to low level contamination for a long period of time (chronic exposure).

The only symptoms encountered in Seveso are those of Chloracne, which appear only in doses of many ng/Kg-body weight per day.

In view of the above, Prof. Schlatter concludes that the exposure of the population on industrial areas to this class of toxic compounds (as evaluated on the basis of the amount present in the adipose tissues) is at least 100 times lower than the critical limit (at which Chloracne appears).

Even though ADI has been widely exceeded by reality, concludes Prof. Schlatter, the final aim must not be forgotten. The intake of dioxins must be reduced below the fixed limit of 1–10 pg/Kg-body weight per day and there is still a long way to go to reach such results.