The UK approach to assessing & managing asbestos in soil & made ground

Transcription

1 The UK approach to assessing & managing asbestos in soil & made ground Professor Paul Nathanail University of Nottingham & Land Quality Management Ltd CIRIA C733 published March

2 The University of Nottingham Britain s Global University Contaminated Land Online Masters Malaysia KeyCSM S4ULs China

3 Land Quality Management Ltd Sound Science: Defensible Solutions CIRIA C733 published March 2014 TRAINING emaq+ CIRIA Introduction Advanced In house Online LQM Sound Science Defensible Decisions CONSULTANCY Risk assessment & SI Sustainability assessments Intelligent client function Expert witness Peer review LQM/CIEH S4ULs Coming Soon KeyCSM

4 C733 Preliminary Risk Assessment Process

5 C733 Risk estimation and evaluation process

6 EU regulation covers One serpentine mineral: Chrysotile CAS Five amphibole minerals: Amosite CAS Crocidolite CAS Tremolite CAS Anthophyllite CAS Actinolite CAS But not: Phyllosilicates (biotite, richterite et al.) Biopyrobole Talc Antigorite (wavy serpentine) Brucite Szaibelyite Halotrichite Pectolite

7 USA Federal Legislation Fed Laws refer to Asbestos in different ways Clean Air Act HAPS CERCLA Haz Subst RCRA Solid waste Clean Water Act toxic pollutant Safe Drinking water act max cont level SoSCA Haz Mat Transport Act OSHA

8 A word means precisely what I want it to mean We have regulations I don t like the way they re written but we are stuck with them 29CFR (b) Asbestosincludes chrysotile, amosite, crocidolite, tremolite asbestos, anthophyllite asbestos, actinolite asbestos, and any of these minerals that have been chemically treated and/or altered. ( ment?p_table=standards&p_id=9995)

9 Almost asbestos McNamee and Gunter (The Microscope vol61 part 1 & volxx part 2) Chemical composition Crystal structure Habit Alteration

10 Signal? I see no signal! Admiral Nelson, Battle of Trafalgar It s what we can t, don t or won t see that poses the latent liability Nano particles driving analytical/ detection techniques Eg Matrix Removal followed by automated particle detection and measurement reporting to spreadsheet (Image J)

11 NIOSH 7400 B Rules Why does 2+2 = 4? What is 2? NIOSH 7400 Appendix B (A rules) for asbestos (DIFFERENT to B rules) NIOSH 7400 Appendix C (B rules) count only ends of fibres, L>5um, W<3um, L:W =>5:1, divide total end-count by 2 Dispute between laboratories due to poor WIDTH counting (were they <3um?) by some labs Resorted to SEM for better measurements; centering & focusing the condenser & understanding when a sample is in focus are KEY skills for an analyst

12 Asbestos-containing materials (ACM) Asbestos cement sheets, slates & pipes Asbestos insulating boards and tiles Insulation/lagging Sprayed coatings Asbestos textiles (rope, yarn and cloth) Millboard, paper and paper products Bitumen felts and coated metal Flooring materials (i.e. tiles) Textured wall coatings and paints Reinforced plastics Mastics, sealants, putties and adhesives

13 (some) Asbestos Relevant Contaminated Land Legislation Land Contamination Health & Safety at Work Construction Design & Management Regulations Part 2A Environmental Protection Act 1990 Town & Country Planning Act Technoprint vs Leeds CC Environmental Damages Regulations Environmental permitting Common law Negligence Rylands vs Fletcher/ Cambridge Water vs Eastern Counties Leather Corby Asbestos specific Compensation act 2006 Control of Asbestos Regulations (2012) Judgements Sienkiewicz v Greif (UK) Limited and Knowsley Metropolitan Borough Council v Willmore, [2011, UKSC 10] Williams v Birmingham University [2011] (EWCA Civ 1242) Copyright C P Nathanail

14 Legal drivers: Dropping the bar! Legal thresholds for asbestos have become ever tighter over the past fifty years Levels of asbestos contamination that might have been ignored in the past are now recognised as significant. Developments in Europe suggest that standards will continue to tighten Dutch NR and MPR values may being reviewed downwards HSE recently proposed reducing the detection limits for background and enclosure leakage testing to 0.001f/ml If landowners and developers are to avoid civil liabilities in future, today s assessments need to be based on sound science and good practice guidance

15 Acceptable levels of environmental exposure Netherlands: negligible risk level of f equivalents per ml and maximum permissible risk concentrations of 0.1 f equivalents per ml WHO: lifelong exposure to f/ml leads to a risk of mesothelioma roughly 10-times the risk of lung cancer This level may provide adequate health protection difficult to judge values are currently under review No UK thresholds have been set for environmental exposures (e.g. from soils) This seems unlikely to change in the foreseeable future. Generic non-exceedance of 10E-5 ELCR is deemed ok Airborne thresholds set for occupational exposures under CAR are much higher than proposed by WHO or Dutch Control Limits (0.1 f/ml over 4-hours and 0.6 f/ml over 10 mins) Clearance Indicator Threshold (<0.01 f/ml) and should be taken only as a transient indication of site cleanliness, and not as an acceptable permanent environmental level. These values cannot be used to assess the acceptability of environmental exposures

16 Asbestos-containing soils What is the problem? If we look hard enough we will find asbestos fibres and/or ACM fragments on all/most sites Occupational exposures CAR 2012 Non-occupational exposures planning and Part 2A regimes Transporting and disposing of asbestos-containing soils Could landowners/developers face future claims under the Compensation Act 2006? A very complex issue -little or no current guidance What are the key questions? How much needs to be present before CAR applies to site investigation and construction activities? Are airborne fibres released from soils in the UK? Do asbestos-containing soils pose any post-development risks to residents and site users? How can any potential risks be assessed? When is remediation necessary? Considering land use (houses, parks, offices), concentration in soil, fibre type(s), ACM type, depths What is a safe level of asbestos in soil?

17 Asbestos-containing soils: What are the costs? Potentially huge cost to the UK economy Justifiable? CAR compliance Do all investigation, remediation and earthworks personnel need training, health screening, RPE? Soil analysis and air monitoring costs? Additional site facilities/measures: welfare, damping down, dust suppression, vehicle washing May require huge volumes of soil to be removed and disposed of All hazardous waste? Landfill Gate prices Landfill tax qualification Transport precautions and costs

18 Asbestos in soil: The long road to UK guidance 1988 Addison et al. The release of dispersed asbestos fibres from soil IOM TM/88/ Asbestos on contaminated sites ICRCL 64/85 (Second edition; amended to reflect Addison et al. findings) 1996 Davies et al. Development and validation of an analytical method to determine the amount of asbestos in soils and loose aggregates HSE 83/1996 Several guidance initiatives including by HSL/Environment Agency Nothing published 2013 Site Investigation Asbestos Risk Assessment For the protection of Site Investigation and Geotechnical Laboratory Personnel AGS Interim guidance (v 2.4) 2014 Ciria Guide to managing and understanding the risks of asbestos in soil and on brownfield sites (C733) (In prep) EIC/CL:AIRE Joint Industry Working Group Industry Code of Practice/ Practitioners guide: Asbestos in soil and construction & demolition materials

19 CIRIA C733 Asbestos in soil and made ground: A Guide to Understanding & Managing Risks Aim: to improve the confidence in and performance of risk assessment and risk management on sites that contain soils or made ground potentially contaminated by asbestos. Authors: LQM: Paul Nathanail, Richard Ogden IOM: Alan Jones, Alastair Robertson CIRIA Joanne Kwan and Owen Jenkins Note: The guide primarily considers soil risk assessments needed to assess risks from long term exposures relating to asbestoscontaining soils under the planning/development control, Part 2A and other environmental legislation. But also refers to health and safety risk assessments required by HSWA and CAR 2012

20 CIRIA C733: Acknowledgements to project steering group PSG Claire Dickinson (chair) Rachael Adams Chris Barrett Jane Beckmann Adam Binney Bill Baker Seamus Lefroy Brooks Stuart Chandler James Clay Hazel Davidson Frank Evans Steve Forster (JIWG Chair) Matt Hussey Matt Griggs Paul Gribble Ian Heasman Simon Hay Phil Hellier Ursula Lawrence Ian Martin Phil Rozier David Robinson Carl Slater Chris Vincett Paula Whittell George Wilkinson Rebecca Williams Wide range of other inputs Thank you all!

21 CIRIA C733: What is in it The ready reference summary It is meant to be brief Chapters 1 & 2 Introduction & Client s guide Chapters 3 to 9 Part 1 - understanding what matters Chapters 10 to 17 Part 2 - assessing potential exposures and risks Conclusions & recommendations (Chpt 18)

22 Estimating the risks Currently, the most valid approach is to calculate the risk associated with predicted exposures using exposure-risk models e.g. based on Hodgson & Darnton 2000 But: These models are for occupational exposures Extrapolation of such models over many orders of magnitude means that resulting risk estimates are indicative only and should not be used as accurate absolute values. Decisions based on these risk estimates must take full account of the uncertainties involved

23 Simple assessment based on risk summary tables Cumulative exposure (from age 30, over 5 yrs) Mesothelioma Lifetime Risk per 100,000 exposed Fibre/ml.years Crocidolite Amosite Chrysotile (Up to 2-fold uncertainty) 6500 (Up to 2-fold uncertainty) 200 (Up to 3-fold uncertainty) (Up to 2-fold uncertainty) 650 (Up to 2-fold uncertainty) 20 (Up to 3-fold uncertainty) (Highest arguable estimate 1500 lowest 250) (Highest arguable estimate 350 lowest 25)) (Highest arguable estimate 100 lowest 2)) 90 (Highest arguable estimate 300 lowest 15) 15 (Highest arguable estimate 80 lowest 2) 3 (highest 20) 5 (Highest arguable estimate 20 lowest 1) (Highest 4) about 10 (Highest arguable estimate 55, lowest insignificant )) about 2 (highest arguable 15) Highest arguable becomes insignificant Highest arguable becomes insignificant Note that the above risks all apply to exposure starting at age 30. The cumulative exposure year is an occupational year assumed to be about 2000 hours. The cumulative exposures in column 1 can be converted to cumulative exposures in fibre/ml.hours by multiplying by 2000; for example 0.01 fibre/ml.years = 20 fibre/ml.hours. (After Hodgson and Darnton (2000), table 11)

24 Lots of known unknowns! Terms and key variables Facts Unknowns Asbestosrelated malignancies Excess Lifetime Cancer Risk (ELCR) Group 1 carcinogen Occupational exposure causes lung cancer/mesothelioma Amphiboles more potent than chrysotile Applicability of models to environmental exposures of children Inhalation (Outdoor and indoors) Exposure scenarios Cumulative exposure (f/ml.yr) Significance of indoor exposures Likelihood of track back to indoor environments Air Airborne asbestos fibres Concentrations (f/ml) commonly encountered at asbestos contaminated sites Soil-to-air relationship Secondary release Disturbance activities Influence of climate Airborne fibres can be released from dry soils in the lab Fibre type and soil type affect concentration To what extent are airborne fibres released in the real world How can the air concentration be reliably estimated from soil concentrations Soil Asbestos-containing soils and madeground Primary release Degradation and deterioration Asbestos/ACM may be present at most sites Degradation rates for ACMs in soils Typical concentrations of ACM and/or asbestos fibres in soil (mg/kg or %)

25 Recommendations The report makes 9 major recommendation to start to address the unknowns and uncertainties: 1. Hazard classification of Asbestos-containing soils 2. Guidance on LW, NNLW and NLW 3. Adapting laboratory analytical reports to suit the purpose of quantitative site risk assessment 4. Fibre releasability database of soils 5. Commercial fibre release testing for site specific soil 6. Current background concentrations of asbestos in air 7. Utilising Dutch research on negligible risk levels 8. Software implementation of models 9. Appropriate record keeping on the presence of asbestos in soils

26 Finally, The guide: Provides a lot of information Should help those with duties and potential liabilities (and their advisors) Should help protect those who work on sites with an asbestos-in-soil hazard May be a step towards deriving more robust sciencebased policy on the management of asbestoscontaining soils across the UK Makes recommendations for further work (eg by JIWG or others)

27 Air monitoring and analysis: Activity-based sampling Preferred method in the US Direct measurement of potential exposure concentrations Compatible with CAR? High risk vs low risk Verification sampling? Occupational hygiene measurements Photos:

28 Fluidized bed asbestos segregator (FBAS) Developed by INEEL (Idaho); EPA mods published in Anal. Methods (Januch et al. 2013) Soil (2g) mixed in sand (18 g) in funnel shaped glass vessel, air is drawn up through the mixture to cause fluidisation, small particles become airborne, as vessel widens velocity decreases, coarse particles fall out and fines continue to filter then analysed by TEM ISO (modified) Air enters through HEPA filter, mineral soil dust trap captures excess;

29 Januch et al. (abstract) there is an approximately linear relationship between the concentration of asbestos in the PE standard (as mass percent) and the mean concentration estimated by the TEM analysis following preparation by FBAS, expressed as asbestos structures captured on the filter per gram of test material (s g -1 ). Method detection limits achieved in these studies ranged from 0.002% to 0.005% by weight, which is approximately 100-times lower than the detection limits that are usually achieved using other analytical methods for asbestos in soil and other solid media.

30 Italy (Eternit case) Europe s largest asbestos manufacturer (roofing & wall products) No smoke stack controls; communities contaminated; no protective equipment for workers for most of the time; >2000 deaths; 650 personal injury claims last plant closed in Italy in 1986 and company went into bankruptcy [] convicted of causing environmental disaster and wilfully failing to comply with safety regulations Final appeal decision pending

31 Korea Asbestos mines in Korea developed from 1930s to produce military supplies for Japan MoE Conprehenisve survey on asbestos control 2009 reported 24 mines Korean Fed for env movement report on Jecheon mine (2009) Remediation is now ongoing

32 Australia Asbestos roofing in WA Asbestos fencing in WA WA 2 nd largest province, remote, San Diego climate much asbestos mined (Wittenoom Crocidolite), most WW buildings contained asbestos

33 Australia Managing Risks from Asbestos-Related Fires WA >10,000 fires/year; 100s of buildings destroyed Features of asbestos fires: breaking, shattering & spalling of asbestos cement; spalling (delamination/ flaking) from explosive steam release, fibre bundles mainly parallel to sheet surface; potential for scatter and dispersion by fire effects, wind action, fire fighting and rain; probability of matrix compromise>>> brittle/ friable; possibility of asbestos DENATURINGand becoming less toxic

34 The sale of asbestos was banned in ooops!

35 Asbestos in Soil: Human Health Risk assessment Needles in haystacks So what? Capricious fibres Asbestos Content Blowin in the wind Fibre Content Fibre Release The big deal Dispersion Cumulative Exposure D O S E - R E S P O N S E

36 To translate the unversed into the well rounded