www.benkeet.com ©2014 ben keet 1 development of the ‘ben keet method’ of house dust analysis to...
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www.benkeet.com ©2014 Ben Keet 1
Development of the ‘Ben Keet Method’ of house dust analysis to identify lead
and other contaminants
Drs. Ben Keet, SQEP, FRSC, MRSNZ, MinstDGeo & Hydro – K8 Ltd
e-mail: [email protected]
After years of cleaning up industrial sites ….
I realised need to focus on the important issues
Like the environmental effects on people,
esp. Children
This requires a change from commercial environmental engineering to social environmental engineering
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However CHANGE, - happens even when you don’t expect it- but not always the way you want - or as fast
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Estimated costs of paediatric lead poisoning, United States, 1997.
Environment Attributable Factor (EAF) = 100%Main consequence = Loss of IQ over lifetimeMean blood lead level in 1997 among 5-year-old children = 2.7 µg/dLA blood lead level of 1 µg/dL I points per child = Mean loss of 0.25
Therefore, 2.7 µg/dL = Mean loss of 0.675 IQ points per childLoss of 1 IQ point = Loss of lifetime earnings of 2.39%Therefore, loss of 0.675 IQ points = Loss of 1.61% of lifetime earnings
Economic consequencesFor boys: loss of 1.61%× $881,027 (lifetime earnings) × 1,960,200 = $27.8 billionFor girls: loss of 1.61% × $519,631 (lifetime earnings) × 1,869,800 = $15.6 billion
Total costs of paediatric lead poisoning = $43.4 billion
Environmental Pollutants and Disease in American Children: Estimates of Morbidity, Mortality, and Costs for Lead Poisoning, Asthma, Cancer, andDevelopmental Disabilities, Philip J. Landrigan, Clyde B. Schechter, Jeffrey M. Lipton, Marianne C. Fahsand Joel Schwartz, The Center for Children’s Health and the Environment, The Department of Community and Preventive Medicine, and The Department of Pediatrics, Mount Sinai School of Medicine, New York, New York, USA; Environmental Health Perspectives • VOLUME 110 | NUMBER 7 | July 2002
For me it started with realizing the social costs of lead poisoning. Searching I only found financial implications :
Whaw !
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Environmental attributable cost by condition
Base-case (US $ Billion)
Lead poisoning 50.9Methyl Mercury tox 5.1Asthma 2.2Intellectual Disability 5.4Autism 7.9ADHD 5
Ref.Leonardo Trasande and Yinghua Liu
Reducing The Staggering Costs Of Environmental Disease In Children,
Estimated At $76.6 Billion In 2008
(published online May 4, 2011; 10.1377/hlthaff.2010.1239), 30, no.5 (2011):863-870 Health Affairs
Lead = 66% of total cost of $ 76.6 Billion just in USA
6 years and a few $m R&D later
same outcomes
Hypothesis: In NZ the cost ‘per person’ is 2 x higherNZ$ 1.5 Billion (annually ! )
reasons:
• NZ houses: Many of wood and w/b – all walls paintedv.s. US houses: Many of brick – only windows and doors painted
• Interiors NZ: - mainly paintedv.s. US: - high use of wall paper
• NZ phased out last lead-based paint around 1982v.s. US phased out lead-based paint around 1965
• NZ average disposable income is much lower than in the USleading to poor maintenance and less re-painting.
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Lead-based paint history
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Pre-1945 - 70 paint > 50% Pb
Start phase out world-wide in late ‘60-ies
Still in use in NZ in mid ‘80-ies
1980 - 1.000.000 households in NZ
1984 BRANZ estimates: 251.000 properties with lead based paint
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Ref. NZ Statistics
Difference US - NZ
NZ
US
(RRP = Renovation Repair Painters)
On January 1, 2011, firms working in pre-1978 homes and child-occupied facilities must be certified and use lead-safe work practices during renovations.
The penalty for noncompliance is $37,000 per day, per violation and possible jail time
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Dominion Post 27 July 2011
Are we taking Lead serious in NZ?
How my journey began
2006 (I just got a handheld XRF analyser)
• Parent from school requests assessment of house and garden as his 2 yr old became sick a few weeks after moving in a new (old) house (‘30-ies)
• Lead level in garden around house was > 2000 mg/kg
• Swipe test of floors gave > 20 mg/m2 of lead (US clearance = 100 μg/ft2)[20 x over]
• Swipes: cumbersome, variable and costly. very dependent on time since cleaning
(info from mother re last cleaning = invariably wrong)
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Late 2006
• More house surveys
• Used battery vacuum cleaner to take dust samples
• Main flaw: Areas most frequented and also most often cleaned
• Surveys biased towards least used and least cleaned areas.
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2007
• Used vacuum cleaner bag to get average dust sample
• Useful as the most used areas are also most often vacuumed
• Started to separate the dust into grain size fractions
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Very first sieved house dust analysis
If on site: analyse painted surfaces & soil
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And mark with lead concentration
Soil
2008: FREE survey at HB Field Days
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• Stand in HBRC
marquee
• Opposite entrance
gate
• 6000 visitors – 3 days
• 14 people signed up
• 4 gave permission to
publish results
Main stumbling blocks
• Home owners don’t want “bad info” on their property (value worries)
• Many prefer not to know (ostriches)
• “If it was an issue, the council would inform us”
• Solution:• Vacuum cleaner bags dropped off at intermediary
(Environment Centres)• Or send direct to independent lab:• Now the ‘Ben Keet Method’ is offered by Hill Laboratories
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Some results
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µm Average Pbdust >300 300 230dust >150 150 385dust >75 75 594dust <75 30 370
y = -0.875x + 516.22R² = 0.4763
0
100
200
300
400
500
600
700
0 200 400
Pb m
g/kg
Seive in micro meters
house 93 RB
Series1
Linear (Series1)
grain size Pb1200 33
300 123150 140
75 22130 282
y = 2439x-0.576
R² = 0.9321
0
50
100
150
200
250
300
350
400
0 500 1000 1500
Pb m
g/kg
grain size
Pb
Power (Pb)
Every analysis tells a story
There are similarities ……
Initial findings:
Analysis of fine and coarse fractions gives total concentration AND an indication where the problem may be:
• Coarse particles containing lead originate mainly from indoors• Fine particles containing lead may be carried in house from outdoors
My hypotheses:
1 Better correlation blood lead level - lead in fine dust (i.e. soil is important)2 Lead concentration in particle seize indicates source3 Mass identification of houses with high lead is possible using
a Aerial photographsb Visual indicators
Possible other factors; lead speciation, bio-availability www.benkeet.com ©2014 Ben Keet 17
Conclusion: ‘Ben Keet Method’ of house dust analysis is Potentially Better Significantly Cheaper
Using dust from vacuum cleaner bag provides:• House average lead concentration in dust for most used areas• Rapid assessment of potential lead exposure• Significant savings compared to wipe tests• Can be carried out off-site – even anonymous
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Recommended remediation of lead-paint surfaces:• Clean surfaces with ammonia / sugar soap solution• Re-paint with acrylic based paint
Recommended for garden soil high in lead:• Ensure good mats at house entrance• Replace soil or cover with new soil + indicator
layer
Further work, recommendations and R&D needed
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Study relationship lead in dust fractions with blood lead level (bll)
Lead dust surveys should be carried out in all pre 1980 houses with
small children
Lead dust house surveys should be recommended by Plunket for all
pregnant woman
Testing for lead in blood of pregnant woman and babies should
become standard in NZ (as in is in the US and many EU countries)
MfE, DHB’s, councils should subsidise remedial work (re-painting /
soil work) of older houses, especially for households with young kids
(just like house insulation)
Housing Authority of Baltimore City is to pay nearly $12 million in court-ordered judgments that it owes former public housing tenants who suffered lead-paint poisoning years ago as children.
By Scott Calvert, The Baltimore Sun8:59 a.m. EDT, August 18, 2011http://www.baltimoresun.com/health/bs-md-brochin-lead-paint-20110817,0,7720622.story?goback=%2Egde_164261_member_68234249
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Thank you for your attention
Questions – discussion……………………..
Reminder: