Arsenic - Soil

EPA recommended reference values compared to other guideline values and standards (all in mg/kg dw):

(H) Human Health based only, (E) Ecological investigation levels, (I) Intervention level (Dutch) remediation required urgently

General comment:

General remark: Arsenic in soil is very undesirable. All human and ecotoxicological calculations result in very low 'no risk' levels (see the US EPA region 9 levels). However arsenic is often part of the natural soil matrix. So many legislations have opted for an elevated arsenic level as guideline level.

Naturally occurring arsenic is better bound and thus less available then anthropogenic (human induced) arsenic. Possibly the aging effect plays a role, however aging for only a few decennia may not create the same binding as millennia as nature has provided for. EPA has opted for a moderate low arsenic level, however urges users to determine the general background level and aim their remedial strategy at 3 - 5 mg/kg dw above the natural background level to ensure the people and their environment will have the protection the natural ecosystem would have provided for.

i More information on arsenic see: http://en.wikipedia.org/wiki/Arsenic

ii http://www.mfe.govt.nz/publications/hazardous/timber-guide-jun97/ (June 1997)

iii National land use specific reference values: a basis for maximum values in Dutch soil Policy, RIVM rapport 711701053 (2007); http://www.rivm.nl/bibliotheek/rapporten/711701053.pdf , The Dutch background and intervention level are based on ‘standard’ soil with 10% organic matter and 25 % clay.  An adjustment of the guideline levels is required for other soil types.  This correction is contaminant specific.

iv The Dutch Guidelines for soil protection are the first source of reference in Singapore (Code of practice on Pollution Control 2000 with amendments made in Feb 2001, June 2002 and Feb 2004)

v Region 9 Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations. Direct exposure pathways. General information and background see http://www.epa.gov/region09/waste/sfund/prg/index.html for table for soil see http://www.epa.gov/region09/waste/sfund/prg/files/04prgtable.pdf and for guide to specific Region 9 guidelines see: http://www.epa.gov/region09/waste/sfund/prg/files/04usersguide.pdf Please note that in the State of California, Cal-Modified PRGs should be used as screening levels for contaminated sites if they are more stringent than the Federal numbers

vi http://hawaii.gov/health/environmental/hazard/pdf/ealsapp1nov2006.pdf  Table B-1 Soil Action Levels use 20 mg/kg as general action level in urban and other areas

vii Soil for agricultural land (paddy fields only); http://www.env.go.jp/en/water/soil/sp.html (February 1994), when no risk to groundwater – only risk for direct ingestion limit is 150 mg/kg dw ; page 7 of  Soil Contamination Countermeasures http://www.env.go.jp/en/water/soil/contami_cm.pdf (2004)

viii http://www.eng.me.go.kr/docs/publication/filedown.html?filename=Green%20Korea%202006.pdf&mcode=A (15 December 2006) Green Korea 2006

ix ÖNORM S 2088-2 : 2000 06 01 : N Altlasten - Gefährdungsabschätzung für das Schutzgut Boden

x First value is maximum concentration for soil brought from elsewhere to be used as replacement soil in a remediation project.  The second value is the maximum level that any sample can have on non-remediated site areas. Since the initiation of the Belgium soil and groundwater legislation on 5 March 1996 the legislation has been amended several times.  The values given here are from the Coordinated version of VLAREBO produced in October 2007 : http://www.ovam.be/jahia/Jahia/cache/offonce/pid/176?actionReq=actionPubDetail&fileItem=721 or if changed go to the search page: http://www.ovam.be/jahia/Jahia/pid/535    Related laws can be found on: http://navigator.emis.vito.be/milnav-consult/faces/consultatieOverzicht.jsp

xi Statistická ročenka životního prostředí České republiky1998, http://www.env.cz/www/zamest.nsf/0/472516581deb3be4c125672f00361b32?OpenDocument , see also Table II.8 and II.9, http://www.env.cz/ZP_03_an/akap_02.htm (II.8 uses 2M HNO3 extraction, while II.9 uses aqua regia extraction)

xii Background levels:   http://www.umweltbundesamt.de/boden-und-altlasten/boden/downloads/hintergrundwerte-anorganische-stoffe.pdf ; Annual loadings : http://www.umweltbundesamt.de/boden-und-altlasten/boden/downloads/Vorsorgewerte.pdf ; investigation and remediation threshold levels : http://www.umweltbundesamt.de/boden-und-altlasten/boden/downloads/Pruefwerte_Massnahmenwerte.pdf

xiii The lower value of 50 mg/kg for vegetable gardens and agricultural soils relates to soil which can have reducing conditions. For germination of agricultural plants, the limit is 0.4 mg/kg determined by Ammoniun Nitrate extraction.

xiv Soil guideline value document March 2002: http://www.environment-agency.gov.uk/commondata/acrobat/sgv1_arsenic_676042.pdf , Based on: 1. total inorganic arsenic concentration in the soil.  2. Not applicable to arsenic present primarily in an organic form or where there is a likelihood of arsine gas being generated. 3. Based on intake of arsenic only and compared with oral Index Dose value. 4. Based on sandy soil as defined in CLR10 (DEFRA and Environment Agency, 2002d).  The lower value of 7 mg/kg for home grown vegetables applies when there is a chance of ingestion of soil attached to vegetables. For toxicological data see also: http://www.environment-agency.gov.uk/commondata/acrobat/tox1_arsenic_675423.pdf  and for plant uptake / bioaccessability : http://www.environment-agency.gov.uk/commondata/acrobat/p506202tr_760444.pdf and for spreadsheet model: http://www.environment-agency.gov.uk/commondata/103601/plant_models_1546130.xls

xv Directives on source/soil definitions values (SSDV) [background] and Fixed Impact values (FIV) in a way similar to intervention values (i.e. if over this value action of some sort is required), however for non-sensitive use often the Dutch value x 2 (main contaminants) or x 5 (trace contaminants) is taken.  Note the SSDV’s have to be ‘x’ times the local background level, where again x = 2 for main contaminants and x = 5 for trace contaminants:  http://infoterrefiche.brgm.fr/PDF/RP-52276-FR.pdf Analysis to be carried out conform AFNOR, or ISO, or other relevant methods (in that order).

xvi SDDV for soil with pH > 7

xvii When inhalation of dust needs to be considered see: http://www.environment-agency.gov.uk/commondata/acrobat/sgv1_arsenic_676042.pdf