Jaana Sorvari

Influence of metal complex formation on heavy metal and free EDTA and DTPA acute toxicity determined by daphnia magna

Abstract The EC 50 values (24h, Daphnia magna ) of Fe 3+ , Cu 2+ , Mn 2+ , Zn 2+ , Cd 2+ and Hg 2+ complexed by EDTA or DTPA were compared with those of the respective uncomplexed metals and free EDTA and DTPA. The experiments gave the following toxicity order: Hg 2+ > Cu 2+ > Cd 2+ > Zn 2+ > Fe 3+ > Mn 2+ . After complexation, the toxicities were 1.1 – 1700 (EDTA) and 7.0 – 3400 (DTPA) times lower. With Hg 2+ however, complexation did not decrease the toxicity. Excluding Cd-DTPA, the toxicity reductions had a high correlation with the conditional stability constants of the respective metal chelates. Compared with the toxicity of free EDTA and DTPA, metal complexation increased the toxicity of EDTA and DTPA considerably. The results of the previous Microtox ® study were well in accordance with this investigation.

Environmental risks at Finnish shooting ranges - A case study

ABSTRACT We studied three Finnish shooting ranges in order to define the extent of the risks associated with elevated environmental concentrations of metals and PAHs. A scoring system revealed that lead, arsenic, and antimony were the most critical contaminants. On Site 3, the concentration of lead in groundwater exceeded the drinking water standard indicating evident health risks. For the remaining two sites we calculated Acceptable Daily Doses (ADD) based on the Reasonable Maximum Exposure (RME) approach and compared them with safe exposure levels. We also used a pharmacokinetic model to determine blood lead levels (PbBs). Risks to biota were assessed using ecological benchmarks and exposure and accumulation models. Prediction of leaching was based on laboratory tests and a distribution model. The health risk assessment for lead resulted in the maximum hazard quotient (HQ) of 1.2 whereas the HQs of As and Sb remained less than 1. Some exposure scenarios produced PbB estimates exceeding 10 μ g dl−1 but based on the uncertainty analysis we expect the health risks to remain insignificant. However, leaching of contaminants presents a risk to groundwater quality. At site 1 the ecotoxicity-based HQs demonstrate high risks to soil biota, small mammals, terrestrial plants and aquatic organisms.

Eco-efficiency in contaminated land management in Finland – Barriers and development needs

In Finland the number of potentially contaminated sites totals ca. 20 000. The annual costs of remediation are 60-70 million euros. Excavation combined with disposal or off-site treatment is the most common soil remediation method. To define which factors make contaminated land management (CLM) eco-efficient and to study whether eco-efficiency has been considered in CLM decisions we carried out a literature survey, two stakeholder seminars, thematic interviews and a questionnaire study on economic instruments. Generally speaking, eco-efficiency means gaining environmental benefits with fewer resources. To assess its realization in CLM, it is necessary to have a more specific definition. In our study, we arrived at a list of several qualifications for eco-efficiency. It was also shown that eco-efficiency has hardly been a real issue in the selection of remediation techniques or generally, in the decision-making concerning contaminated sites. The existing policy instruments seem to be insufficient to promote eco-efficiency in CLM. Several concrete barriers to eco-efficiency also came up, urgency and lack of money being the most important. The scarcity of the use of in situ remediation methods and the difficulties involved in recycling slightly contaminated or treated soil were considered to be major problems. Insufficient site studies, inadequate or unsuitable methods for risk assessment and cost evaluation, and deficient and mistimed risk communication can also hinder the realization of eco-efficiency. Hence, there is a need to promote the use of more eco-efficient remediation techniques and to develop CLM policy instruments, guidelines, and participatory processes and methods to assess the eco-efficiency of CLM options.

Low-level determination of EDTA and DTPA in natural waters by gas chromatography

SummaryA new analytical method and the method validation for the determination of ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) in lake and sea water is presented. An aqueous sample, after evaporation to dryness, was treated with an esterification reagent. The resulting ethyl ester derivates were determined by capillary gas chromatography using a nitrogen phosphorus specific detector (GC-NPD). The response was linear up to 5 mg L−1. The recoveries from lake and sea waters were 59–105 % for EDTA and 86–112 % for DTPA. The run-to-run repeatabilities (R.S.D.) were 2–8 % for EDTA and 4–11 % for DTPA depending on concentration and the reproducibilities (R.S.D.) were 6–13 % and 3–11 %, respectively. The limits of detection for EDTA and DTPA were 3 and 12 μg L−1 in distilled water, respectively. The method is simple to use and reliable as shown by the analysis of samples of lake water that is influenced by pulp and paper industry.

Development of a gas chromatographic method for the simultaneous determination of trace amounts of ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid in natural waters

A GC method for the simultaneous determination of ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) in natural waters is described. The method was studied with spiked samples of distilled water, sea-water (2 matrices) and humic-containing lake water. An acidified 5–10 ml sample was evaporated and esterified with C2H5OH, containing H2SO4 and CH3COOH catalysts and CH3(CH2)15CN as an internal standard. The esterified sample was extracted with C6H5CH3, neutralized with KHCO3, dried with anhydrous Na2SO4 and analysed by GC with nitrogen–phosphorus selective detection. The best recoveries were obtained by the esterification in 100 °C for 3 h. The tetraethyl ester of EDTA and pentaethyl ester of DTPA were further identified by mass spectrometry. In the sea- and lake water matrices, the recoveries of EDTA and DTPA were 80–110%. High concentrations (above 50 mg l–1) of iron (Fe3+) interfered considerably in the determination of DTPA. For EDTA the interference was insignificant with iron concentrations below 500 mg l–1.

Measuring eco-efficiency of contaminated soil management at the regional level

Eco-efficiency and sustainable development are the key environmental topics and goals for todays society that we should strive for in all activities, including contaminated soil management (CSM). However, particularly at the regional level, CSM is studied to a lesser extent from this perspective and practical means to monitor and assess sustainability or eco-efficiency are not widely available. This study aims to fill this gap by developing indicators to measure and monitor the development of regional eco-efficiency of CSM. The indicators can be used to support decision-making at the regional level since many CSM decisions, such as prioritisation of sites and the number of soil treatment and storing facilities, are made regionally. To start with, we surveyed the methods available for determining eco-efficiency and suitable indicators to monitor and measure the development of CSM regionally. We used life cycle analysis (LCA) and material flow analysis (MFA) to identify factors that the environmental indicators should cover, and also involved economic indicators. We ended up with a selection of 28 indicators, which can be classed into three different categories: background indicators, environmental indicators and economic indicators. We further demonstrated the use of the indicators by applying data from three different regions in Finland, and evaluated their suitability. On the basis of the results we recommended 15 indicators for continuous follow-up and decision-making purposes. Even though these indicators are suitable for monitoring and measuring the eco-efficiency of CSM at the regional level, unfortunately we found several data gaps related to the actual remediation projects which impede their use in practice. The data collection practices therefore need to be regionally developed.

Assessment of Ecological Risks at Former Landfill Site Using TRIAD Procedure and Multicriteria Analysis

Old industrial landfills are important sources of environmental contamination in Europe, including Finland. In this study, we demonstrated the combination of TRIAD procedure, multicriteria decision analysis (MCDA), and statistical Monte Carlo analysis for assessing the risks to terrestrial biota in a former landfill site contaminated by petroleum hydrocarbons (PHCs) and metals. First, we generated hazard quotients by dividing the concentrations of metals and PHCs in soil by the corresponding risk-based ecological benchmarks. Then we conducted ecotoxicity tests using five plant species, earthworms, and potworms, and determined the abundance and diversity of soil invertebrates from additional samples. We aggregated the results in accordance to the methods used in the TRIAD procedure, conducted rating of the assessment methods based on their performance in terms of specific criteria, and weighted the criteria using two alternative weighting techniques to produce performance scores for each method. We faced problems in using the TRIAD procedure, for example, the results from the animal counts had to be excluded from the calculation of integrated risk estimates (IREs) because our reference soil sample showed the lowest biodiversity and abundance of soil animals. In addition, hormesis hampered the use of the results from the ecotoxicity tests. The final probabilistic IREs imply significant risks at all sampling locations. Although linking MCDA with TRIAD provided a useful means to study and consider the performance of the alternative methods in predicting ecological risks, some uncertainties involved still remained outside the quantitative analysis.

Updating and testing of a Finnish method for mixed municipal solid waste composition studies

More efficient recycling of municipal solid waste (MSW) is an essential precondition for turning Europe into a circular economy. Thus, the recycling of MSW must increase significantly in several member states, including Finland. This has increased the interest in the composition of mixed MSW. Due to increased information needs, a method for mixed MSW composition studies was introduced in Finland in order to improve the national comparability of composition study results. The aim of this study was to further develop the method so that it corresponds to the information needed about the composition of mixed MSW and still works in practice. A survey and two mixed MSW composition studies were carried out in the study. According to the responses of the survey, the intensification of recycling, the landfill ban on organic waste and the producer responsibility for packaging waste have particularly influenced the need for information about the composition of mixed MSW. The share of biowaste in mixed MSW interested the respondents most. Additionally, biowaste proved to be the largest waste fraction in mixed MSW in the composition studies. It constituted over 40% of mixed MSW in both composition studies. For these reasons, the classification system of the method was updated by further defining the classifications of biowaste. The classifications of paper as well as paperboard and cardboard were also updated. The updated classification system provides more information on the share of avoidable food waste and waste materials suitable for recycling in mixed MSW. The updated method and the information gained from the composition studies are important in ensuring that the method will be adopted by municipal waste management companies and thus used widely in Finland.

Shooting Ranges: Environmental Contamination

Environmental contamination at outdoor shooting ranges has raised concern in several countries globally. Although the focus has been on lead (Pb), there are also other contaminants involved, including arsenic and antimony, which need to be considered due to higher mobility and consequent risk to water quality or considerable toxicity to humans and biota. The occurrence and concentration level of the contaminants at a particular shooting range depend on the properties of the site such as shooting types, use pattern, and environmental characteristics. Hence, the magnitude and probability of risks vary site-by-site. The risks usually become prevalent when shooting activities are ceased and land use is changed. In the latter case, it is necessary to assess the risks to find out whether some risk management actions, such as remediation, are needed. There are several methods available for site-specific risk assessment, and selecting the suitable ones for a particular case is challenging. Certain analytical problems also aggravate risk analysis. Although there are several remediation methods available, very few are technically, not to mention economically, feasible in all cases. Fortunately, measures to minimize further environmental impact have already been implemented in many operating ranges.

Promoting justified risk-based decisions in contaminated land management

Decision making and regulatory policies on contaminated land management (CLM) are commonly governed by risk assessment. Risk assessment, thus, has to comply with legislation, but also provide valid information in terms of actual risks to correctly focus the potentially required measures and allocate the available resources. Hence, reliable risk assessment is a prerequisite for justified and sustainable risk management. This paper gives an introduction to the Finnish risk-based regulatory framework, outlines the challenges within the policies and the practice and provides an overview of the new guidance document to promote risk-based and sustainable CLM. We argue that the current risk assessment approaches in the policy frameworks are not necessarily efficient enough in supporting justified risk-based decisions. One of the main reasons for this is the excessive emphasis put on conservative risk assessments and on generic guideline values without contributing to their appropriate application. This paper presents how some of the challenges in risk-based decision making have been tackled in the Finnish regulatory framework on contaminated land. We believe that our study will also stimulate interest with regard to policy frameworks in other countries.