Risk Assessment and Methods of Determination of Contaminats

Risk Assessment and Methods of Determination of Contaminats in soil TAIEX Workshop AGR 43629 Azerbaijan, Baku, 21 -22. 2. 2011 Merja Eurola Research Scientist MTT Agrifood Research Finland

Goverment Decree on the Assement of Soil Contamination and Remediation needs • Based on assessment of hazard to HEALTH or ENVIRONMENT • Things to consider in the assessment of harmful substances in the soils • • • concentration overall amounts properties location background concentration • • • soil and groundwater conditions possibility of spreading purpose of the use for the area the severity of the health and environment hazard possible combined effects of substances • Background concentration, threshold value, lower and upper guideline value have beed defined for the contaminanats – these values help the assessment

Goverment Decree on the Assement of Soil Contamination and Remediation needs • Soil is regarded contaminated • In industrial, storage or transport are or corresponding are if the concentration of one or several harmful substances exceed the upper guideline value • In other areas soil is contaminated if the concentration of one or several harmful substances exceed the lower guideline value • Guideline value have been defined by their ecological risks or health risks • Reliable assessment requires • Representative sampling • Strandardized or corresponding reliable/validated methods • Standardized methods are not always available

Examples of threshold and guideline values for contaminants in soils in Finland Substance (symbol) Natural concentration mg/kg Arsenic (As) 1 (0, 1 -25) Mercury (Hg) 0, 005 (<0, 005 -0, 05) Cadmium (Cd) 0, 03 (0, 01 -0, 15) Lead 5 (0, 1 -5) PAH PCB DDT-DDD-DDE Atrazine Petrol fractions (C 5 C 10) Petroleum fractions (>C 10 -C 40) Trichlorobenzenes Hexachlorobenzene Dichlorophenols Threshold value mg/kg 5 0, 5 1 60 15 0, 1 0, 05 Lower guideline value mg/kg 50 2 10 200 30 0, 5 1 1 Higher guideline value mg/kg 100 5 20 750 100 5 2 2 100 500 300 0, 1 0, 01 0, 5 5 0, 05 5 20 2 40

Goverment Decree on the Assement of Soil Contamination and Remediation needs • Assessment must be done if the one or several harmful substances exceed the threshold value • If the background concentration is higher than the threshold value, the background concentration is regarded as threshold value • Risk assessment should consider soil conditions and land use, maybe toxicity and leaching tests • Main receptors: groundwater, surface water, food safety, ecosystems • Laboratory should be accredited or should poses a quality control system

Risk Assessment • “Polluter pays” – principle • In Finland polluter is first responsible for remediation, secondly the land owner if the polluter cannot be legally addressed and finally community/government (public authorities) • Not always applicable principle (historical contamination, large scale transboundary contamination) • Polluter does not exist anymore, cannot be identified, may not be able to pay remediation • Land user cannot be held responsible for all diffuse inputs

What does accreditation mean? • Accreditation is a procedure to recognize a laboratory’s competence and reliability to carry out specific tasks/tests → CERTIFICATE • Public authorities, industry an commerce usually require this evidence of competence before co-operating with the laboratory • In Finland FINAS (Finnish Accreditation Service) organizes accreditation activities according to the standard EN ISO/IEC 17025 General reguirements for the competence of testing and calibrationg laboratories • Assessment srenghtens quality management and technical competence of the laboratory and promotes to continuous improvement • Laboratories need to • • have programme and policy for quality assurance paricipate and show performance in proficiency testing in the scope

Determination of metals from soil • Choice of the method depends on analytical need • • Total concentration vs. soluble concentrations Guideline values are total concentrations • Aqua regia -extraction is recommended for metal analyses • • • Does not extract metals that are strongly bound to silicate minerals Extracts about 80% of metals Internationally comparable method • Information of soluble concentrations help in risk assessment (solubility of the toxic substance, bioavailability to plants, animal, micro-organisms) • Different methods available for extraction of soluble fraction of metals like, AAAc-EDTA extraction • Besides contaminant analyses, it is also recommended to analyse other soil parameters for example p. H and electrical conductivity, organic carbon, soil type which control the fate and transport of substances in soils

Determination of metals from soil • Measurement of metals • AAS: grafite furnace-AAS, flame-AAS, hydride formation –AAS (As, Se), cold vapour-AAS (Hg) • ICP-OES • ICP-MS, lowest detection limits Mercury analyser Varian Grafite furnace AAS

Organic contaminants in soils • Organic contaminants are volatile/biodegradable Parameters Solvents VOX Phenols Chlorinated pesticides and PCB TPH PAH Metals Mercury Holding time 24 h 7 days Unlimited 15 days • Bioavailability of organic contaminants can change over time due complexation, degradation, loss by volatilization, runoff or leaching • Most immobile contaminants are hydrophobic and lipophilic and bind strongly to organic material and soil particles • Organic carbon material affects the bioavailablility of organic compounds

Determination of organic contaminants from soil Soil sample including semivolatile and non-volatile compounds Solvent extraction Concentration, exchange into other solvent Clean-up procedure Measuremet Choice of a solvent and solvent system depend on the matrix, physical properties of analytes, equipment available No single solvent is universal: acetone/hexane or heptane, methylene chloride/acetone, toluene/methanol, heptane, pentane etc. Extraction systems: separatory funnel, Soxhlet extractor, microwave oven, supercritical fluid extraction Extract is concentrated, often exchanged into a solvent compatible with further analyses

Measurement of organic contaminants Measurement with chomatography GC-FID, GC-MS, HPLC, LC-MS Microwave digestion

Uncertainty of measurements • No measurement is exact • Quantification of the doubt about the measurement result • Systematic and random error, expanded uncertainty 95% confidence limit • Expressing results • Same units as in legislation • Cd 11 ± 2 mg/kg • Uncertainty has to be taken into account when comparing results to guideline values • Cd lower guideline value 10 mg/kg, result 11 ± 2 mg/kg • 11 -2 = 9 mg/kg result is under the guideline value • Cd result 13 ± 2 mg/kg 13 -2 =11 mg/kg result exceeds the guideline value

Soil quality stardard methods • • • ISO 11466: 2007 Soil quality. Extraction of trace elemets soluble in aqua regia. ISO 11047: 2007 Soil quality. Determination of cadmium, chromium, cobalt, copper, lead, manganese, nickel and zinc in aqua regia extracts of soil. Flame and electrothermal atomic absorption spectrometric methods, ISO 14154: 2007 Soil quality. ISO 10382: 2007 Soil quality. Determination of organochrine pesticides and poluchlorinated biphenyls. Gas choromatographic method with electron capture detection ISO 15009: 2007 Soil quality. Gas chormatographic determanation of the content of volatile aromatic hydrocarbons, naphtalenen and volatile halogenated hydrocarbons. Purge-and-trap method with thermal desorption. ISO 16287: 2007 Soil quality. Determination of polycyclic aromatic hydrocarbons (PAH). Gas chromatographic method with mass spectrometric detection (GC-MS) ISO 22155: 2007 Soil quality. Gas chromatographic quantitative determination of volatile aromatic and halogenated hydrocarbons and selected ethers. Static headspace method. ISO 16703: 2007 Soil quality. Determination of content of hydrocarbon in the range of C 10 to C 40 by gas chromatography. ISO 11264; 2007 Soil quality. Determination of herbicides. Method using HPLC with UV-detection.

Risks in Agriculture • Contamination in agriculture • Sources: atmospheric deposition, fertilizers, applications of pesticides, manure, sludges, biowastes • Risks: accumulation of persistent contaminants, leaching rates of contaminants to water ecosystems, food safety • The farmer should be encouraged to for good agricultural practises and sustainable use of land → farmer needs support like guidelines for applications, training, help in economic issues etc. • Long term goal: balanced inputs and outputs (nutrients, metals, pesticides), so that healthy soil is maintained, concentrations of food products meet the standards and leaching to groundwater is minimized

Cadmium in Finnish agro-ecosystems Ritva-Mäkelä-Kurtto et. al. 2003 • Risk assessment of Cd in fertilizers using international models • 3 crops were studied: wheat, potato, sugar beet • Cd concentration 2. 5 mg/kg P (present content in Finland) → inputs and output in balance • Cd concentration 50 mg/kg P (maximum allowed content) → in 100 years Cd in soil and soil water would increase 10 -50%, in crops 5 -15% • Cd concentration 138 mg/kg P (average content in P fertilizers in Europe) → in 100 years Cd in soil and soil water would increase 50 -150%, in crops 20 -40% • Greatest increase was in potato cultivation

Degree of Ministry of Agriculture and Forestry 12/2007 • Limit values for harmful metals in fertilizers • Limit value for Cd in mineral fertilizer containing at least 2. 2% P is 30 mg/kg P • Highest Cd load from fertilizers must not exceed 1, 5 g/ha for one year or 6 g/ha for four years Element Limit value mg/kg dm Arsenic, As 25 Mercury, Hg 1, 0 Cadmium, Cd 1, 5 Cobalt, Co 300 Chrome, Cr 300 Copper, Cu 600 Lead, Pb 100 Nickel, Ni 100 Zinc, Zn 1500

Thank You!