Merja Eurola Research Scientist MTT Agrifood Research Finland Monitoring and sampling of contaminated lands

MTT in numbers MTT operates under the Ministry of Agriculture and Forestry. Finland’s leading research institute in the agriculture, food and environment sectors Our organization employs 800 professionals, 300 of whom work in research. We operate in 14 locations around Finland. MTT’s total expenditure in 2009 amounted to 52 M€, a third of which came outside budget financing. In 2009, MTT researchers published a record number of 198 peer refereed scientific articles.

MTT’s locations MTT operates in 14 different locations around Finland

MTT’s organization

Arable soil – a valuable resource Uncontaminated, fertile soil yields high quality and quantity crops for food supply Soil contamination has a great impact on surface and groundwaters Soil is susceptible of many threads, importance of soil protection for agriculture is recognized internationally Soil Thematic Strategy 2006 – objective is to halt and reverse the process of soil degradation Proposed Soil Framework Directive – a legislative instrument to protect of soil from unsustainable use. Not yet adopted by the Council. No legal standard for soil quality have been set at the EU level, not all EU countries have specific legislation on soil protection

Chemical threads to soil Toxic inorganic compounds Metals and semimetals Cr, Cu, As, Ni, Zn, Cd, Pb, Hg, V Syanide Organic contaminants Oil, fuels (petroleum hydrocarbons, volatile organic hydrocarbons) Organochlorine compounds BTEX (benzene, toluene, ethyl benzene, xylene) PCBs (polychlorinated biphenyls), dioxins Fenols PAH (polycyclic aromatc hydrocarbons) Pesticides and biosides, especially persistet pesticides, HCH, DDT, DDE Nurtrients Nirtogen and phosphates

Soil investigation Set objectives of the study Review the existing data Get background information Preliminary site investigation Set a sampling plan and strategy Collect samples Analyse samples Interpret and report data Collect all the information that help to with designing the investigation: history, land use, site geology, groundwater and surface water pathways, local topograpfy, general site condition and land use Target is a sample that represents actual environmental conditions Object is to monitor nature, decree and extent of contamination Pretreat and analyse samples with appropriate methods

Soil sampling plan Sampling objectives, site information Local contamination or diffuse contamination Sampling pattern: judgemental, systematic, stratified Depth (topsoil/subsoil), type and number of samples Sampling techniques (hand augers, test pits, borehole sampling) Order of sample collection (start the least contaminated site) Quality assurance (field QC samples) Handling and sample preservation Sample transport, storage (cooled below 5 °C, protected from sunlight)

Sampling of volatile compounds Sample should be taken to minimize volatilization Undisturbed samples, collect quickly, e.g. coring tool or cylinder Glass, aluminium or PTFE (Teflon) containers are suitable, properly sealed Containers must be filled to the top (minimum air space) Pre-weighted containers containing solvent (methanol) may be used Special sample containers for dynamic head-space analyses are available

Soil sampling tools Different stainless steel hand augers used in MTT

Soil sampling Sampling from lower horizon Taking soil fertility samples

Soil sampling Drilling soil samples

Soil sampling Taking samples 30 cm x 5 cm tube auger

Soil sampling Documentation of data in all stages must be done Financial aspects often limit the number of samples Composite samples Cost effective, number of the samples can be reduced When the cost of the analytes is high compared with the cost of sampling Represent average concentrations More acceptable to homogenous sites (like cultivated topsoil) Large number of samples Volatile and semi volatile compounds are not suitable of composite sampling No more than 4 composites are recommended When comparing the results to guideline values, the guideline value must be divided with the number of composites to get a new guideline value

Errors in soil sampling Sampling plays a key role in soil investigations. It important is to ensure that the samples are representative. Heterogeneity of contaminated soil cause error (soil type, structure, contamination) Sampling and samples pretreatment can cause significant errors to the results which can be greater than errors of chemical analyses Errors can arise at any stage of sampling: choice of location, sample collection, contamination from tools, cross contamination, handling, storage, transport, sub- sampling Quality assurance in sampling and chemical analyses is essential requirement

Soil sampling standards EN ISO/IEC 10725:2005 defines general requirements for competence of testing including sampling ISO standards – Soil quality. Sampling. ISO Guidance on the design of sampling programmes ISO Guidance on sampling techniques ISO Guidance on safety ISO Guidance on the procedure for the investigation of natural, near-natural and cultivated sites ISO Guidance on investigation of soil contamination of urban and industrial sites ISO standards present general principles for designing of sampling programmes and performing sampling FAO, US EPA, EU national guidelines

Monitoring Measurement of contaminated concentrations are needed to assesment of risks Classical soil monitoring – monitoring of the state measurement of concentrations of substances in soil in regular intervals Frequency 5-10 years interval adequate to measure changes Local contamination from industrial activities etc. Diffuse inputs Large scale diffuse pollution – transboundary Atmospheric depositions, agricultural activities, waste recycling The availability of substances crop uptake Results evaluate impacts and future state, trends

Monitoring of Finnish arable land In Finland the long-term monitoring of arable land at country level begun in 1974 The target is to study soil chemical quality and changes in it with time Systematic monitoring makes it possible to detect changes caused by by agricultural management practises and pollutants from anthropogenic sources It produces information that helps in developing sustainable agriculture and maintaining high quality crops

Monitoring of Finnish arable land Sampling sites, season and methods have been kept the same since the beginning Sampling sites sites sites sites (picture) Surface layer (0-20 cm), 4 corners of the 10X10 m sampling area, sampling season early summer

Monitoring of Finnish arable land Analyses Soil type pH, electrical conductivity Volume weight Organic carbon Mineral elements (AAAc, pH 4.65) Trace elements, (AAAc-EDTA) In 1998 trace elements (aqua regia) B, Se (boiling water) Solubility of some trace elements at different pH levels according to Mäkelä- Kurtto Pre-treatment Fresh soil samples were crushed, homogenized, dired at 35 °C, ground through 2-mm sieve.

Monitoring of Finnish arable land 1998 Soil thematic maps, agua regia extractable Cd, Pb, As Ritva Mäkelä-Kurtto et al. 2007