Download The Worcester Roots Project

The Worcester Roots Project
Using Plants to Repair the Soil
Workshop Outline
1. Introductions
2. The Worcester Roots
Project
• Effects of Lead on Health
• Lead Statistics by
Geography
• Legal Climate
• Risk of Soil Lead
• Remediation Options
– good growing practices
– reducing bioavailability
– reducing exposure
– phytoremediation
3.
The Food Project’s work
•
short overview on the
food project,
the history of the
Dudley community
a history of the Urban
Education program,
and our soil testing and
remediation methods
•
•
•
4. Interactive Game
5. Wrap Up
OUR MISSION
The primary purpose of the
Worcester Roots Project is
direct action to remove
contamination by lead, other
heavy metals, and
hydrocarbons from Worcester
soils.
Our aim is to empower
communities to protect their
environmental health.
Health Effects
• Lead poisoning interferes with the development of the
nervous system, bones, reproductive system, endocrine
system, and kidneys. It causes reading problems, learning
disabilities, reductions in IQ, and attention span.
• Numerous studies show that every 10 mcg/dL increase of
blood lead level results in a 2-7 point decrease in IQ.
From: Jacobs, David E. “The Health Effects of Lead on
the Human Body,” Lead, Perspectives Magazine
(November/December 1996).
• Lead poisoning is the most common and most
preventable environmental public health problem
(ATSDR).
Health Effects, cont.
• Children absorb lead (50%) more readily than adults (5%).
• A study by Joplin revealed that children who have eaten
breakfast absorb 2-10% of the lead they ingest, whereas children
who have fasted absorb 50-80%.
• Eating foods high in calcium, phosphorus, and iron reduce the
rate of lead absorption.
• Adults store inert lead in their bones. It is mobilized during
pregnancy and lactation, especially if mothers have calcium
deficiency.
• Unless the mother is lead poisoned, breast milk contains
comparable amounts of lead as formula and cow’s milk.
RISKS FROM EXCESSIVE
CHRONIC DIETARY LEAD
•
Most Important Soil-Pb Risk is to Children:
•
Health Effects from Excessive Absorbed Pb:
– Children absorb a higher fraction of dietary Pb.
– Children are more exposed due to hand-to-mouth play.
– US Geometric mean for children, 2002
– Neurobehavioral Impairment
• I.Q. Reduction; behavior problems.
– Hearing loss.
– Balance instability.
– Interfere with enzymes; anemia.
–. . .
– Encephalitis.
– Death.
3.5 µg/dL
> 10-15 µg/dL
> 40 µg/dL
>100 µg/dL
Nation Still at Risk
• Nearly 1 million children under the age of six have blood lead levels
higher than the lead safety threshold of 10 mcg/dL that has been
established by the U.S. Centers for Disease Control and Prevention.
– From: Screening Young Children for Lead Poisoning: Guidance for State
and Local Public Health Officials. U.S. Centers for Disease Control and
Prevention, 1997.
• 64 million homes in the United States contain lead paint.
– From: Report on the National Survey of Lead-Based Paint in Housing,
Base Report. U.S. Environmental Protection Agency, Office of Pollution,
Prevention and Toxics, April 1995.
Nation at Risk, cont.
• Over 80 percent of all homes built before 1978 in the U.S. have leadbased paint in them. The older the house, the more likely it is to
contain lead-based paint and a higher concentration of lead in the
paint.
– From: What Every Parent Should Know About Lead Poisoning in
Children. U.S. Centers for Disease Prevention and Control.
• Children of some racial and ethnic groups living in older housing are
disproportionately affected by lead. For example, 22% of black
children and 13% of Mexican-American children living in housing
built before 1946 have elevated blood lead levels compared with 6% of
white children living in comparable types of housing.
Massachusetts at Risk
– Lead poisoning is steadily declining is MA.
– In 1998, 1 out of 35 children screened in MA had blood lead levels
of 10 ug/dL or greater.
– MA has the second largest stock of old homes (before 1950) at
47%. The state leads the nation in the number of old homes
occupied by tenant families.
UGROW
Urban Garden Resources Of Worcester, a project of the
Regional Environmental Council
HOMES:
• 11,000 houses in WORCESTER
County have a high risk of lead
hazards.
Source: EPA / CDC Searches using Scorecard.org (Environmental Defense)
Legal Climate - Lead Paint
• 1978-lead paint banned in the US.
• 1986- leaded gasoline banned in the US.
• Bensome vs. Kokoras (1984) establishes the precedent that
homeowners are liable for the exposure of children to lead.
• In MA, lead screening is mandatory for children under six.
• Lead paint abatement is mandatory in homes where children under six
live. This is enforced by the City Department of Public Health, which
visits homes where children with elevated lead have been identified.
Legal Climate - Lead Paint cont.
• There is a state tax credit for deleading. There are also no and low
interest loans and mortgage refinancing available for deleading.
• As of 2000, moderate risk deleading is an option, where homeowners
can get certified to delead their own properties.
• A deleaded home is not a lead free home. Renovations reveal lead
paint that has been covered up by wallpaper, siding, or encapsulating
paint.
• A study comparing Worcester county and Providence Country
concluded that the Massachusetts policy, which requires lead paint
abatement of children’s homes and places liability for lead paint
poisoning on property owners may have substantially reduced
childhood lead poisoning.
Properties receiving federal
assistance may need to
have the soil tested under
HUD regulations. Soils
with 5000 ppm or more
must be abated. This
involves removing the top
6 inches of soil and adding
at least 2 inches of clean
soil OR paving OR deep
tilling.
Photo Source:
There are no state
regulations requiring soil
testing or remediation.
“Reducing Children’s Risk from Lead in Soil”
Ryan et al.
1/1/04
Environmental Health and Technology
How Much Lead is Too Much?
• Under 400 ppm: Urban Background
• 400-1200 ppm: Hazard for Garden and Play
Areas
• Over 1200 ppm: Hazard for All Soils
– (EPA, 2003)
• Soil is tested using composite sampling and
mass spectroscopy or X-ray fluorescence.
Risk from Soil Pb is through Soil
Ingestion, not from Garden Foods.
• If Good Urban Gardening Practices are
•
•
followed, garden crop Pb is increased only
slightly when soil Pb is 500-1000 µg/g.
Living in an area with soil Pb in excess of 500 to
2000 mg/kg may increase children's blood Pb
significantly (HUD; CDC; EPA).
Thus, the dominant pathway for soil Pb risk to
humans is inadvertent soil ingestion by infants
and children.
• To prevent this risk, one can move the child;
remove and replace the contaminated soil; or
treat the soil to reduce soil Pb bioavailability.
Source: Rufus Chaney, USDA
Total Pb distribution of Parkside Neighborhood
Number of Soil Samples
120
100
99
89
80
62
60
40
15
20
11
6
8
3
1
0
<375
<1000
<2000
<3000
<4000
<5000 <10000 <15000 <26000
Pb (ppm)
Source: Samantha Langley-Turnbaugh, Univ. Southern Maine
Garden 1
Garden 1
Total Pb and DTPA
Pb uptake in S.oleracea
700
612
307
584
300
500
400
300
237
224
µg/g dry weight
mg/kg of Pb
600
350
250
200
150
200
100
100
50
0
0
22
T-P b B H
T-P b A H
DTP A B H
DTP A A H
Source: Samantha Langley-Turnbaugh, Univ. Southern Maine
Shoots
Roots
Garden 2
Garden 2
Total Pb and DTPA
Pb uptake in S.oleracea
3500
900
3043
2822
2500
2000
1500
1000
783
800
µg/g dry weight
mg/kg of Pb
3000
716
643
700
600
500
400
374
300
200
500
100
0
T-P b B H
T-P b A H
DTP A B H
DTP A A H
Source: Samantha Langley-Turnbaugh, Univ. Southern Maine
0
Shoots
Roots
Spinach Shoots vs. Weed Shoots in Uptake of Pb
ug/g dry weight
600
479
500
374
400
307
300
200
100
105
86
22
29
13
0
1
2
Garden Spinach Shoots
Source: Samantha Langley-Turnbaugh, Univ. Southern Maine
3
4
Garden Weed Shoots
RISK OF SOIL/DUST Pb TO CHILDREN
•
•
•
Some soils contain substantial levels of CaCO3, or
other alkalinity which can neutralize stomach acidity.
Any process which prevents stomach acidification
should reduce soil Pb bioavailability.
Absorption of soluble Pb compounds during fasting
is about 60-80%, but only 1-5% when ingested with a
nutritious complex meal.
Prolonged fasting by urban poor children may be a
primary causal factor in their Pb absorption and Pbdisease compared to suburban children.
Source: Rufus Chaney, USDA
Bioavailability of Soil Pb to Humans
Under Fasting or Fed Condition.
Results of human feeding studies with soil from the
Bunker Hill Superfund Site (Maddaloni et al., 1998).
Group Age Weight Pb Dose
Soil Dose Bioavailability
kg
µg
mg
Fasted 28
59.7
213
72.9
26.2 (18.0-35.6)
Fed
67.9
242
82.9
2.52 (0.2-5.2)
N=6
yrs
28
Source: Rufus Chaney, USDA
%
Soil Remediation Options
• Remove contamination: Remove the lead
through excavation ($2 million/acre) or
phytoremediation.
• Reduce exposure: Cover soil with mulch,
stone, new soil, or raised beds. Keep soil out of
bodies by moving play and garden areas,
using a doormat, removing dirty shoes and
clothes outside, and washing vegetables.
• Stabilize soil: Keep lead in place by planting
grasses and bushes.
• Reduce Bioavailability: Add compost or
phosphates to bind lead as
chloropyromorphite. Bioavailability reduces
by 20 to 43%.
Good Gardening Practices to
Reduce Soil Lead Risk
~from UMASS
• Locate gardens away from old painted structures and heavily
traveled roads.
• Give planting preferences to fruiting crops (tomatoes, squash,
peas, sunflowers, corn, etc.).
• Discard old and outer leaves before eating leafy vegetables.
Peel root crops. Wash all produce.
• Incorporate organic materials such as finished compost,
humus, and peat moss.
• Lime soil as recommended by soil test (pH 6.5 minimizes lead
availability).
• Keep dust to a minimum by maintaining a mulched and/or
moist soil surface .
In Practice, Incorporating Compost
Reduces Pb Risks in Several Ways.
• Highest Pb is usually on soil surface.
•
•
•
Incorporation of compost with rototiller mixes Pb
with tillage depth.
Phosphate and Fe in compost transform soil Pb
into forms with much lower bioavailability.
Compost amendment supports strong growth of
turfgrass, making it much more difficult to eat the
soil or drag it into your house.
Can measure highest Pb near house using XRF
and remove that soil to landfill before
incorporating compost and tilling.
Source: Rufus Chaney, USDA
Biosolids Compost Amendment
Can Reduce Soil Pb Risks.
• Compost increases Pb adsorption by most soils.
– Organic Matter, Phosphate, Hydrous Fe oxides, CaCO3
• Modern biosolids composts contain low levels of
•
•
Pb; Pb was removed from gasoline, food, and
water; industrial pretreatment.
Compost application reduces plant uptake of Pb.
Compost Pb has very low bioavailability based on
feeding studies with livestock. Identified a noeffect level of 300 mg Pb/kg dry biosolids fed at up
to 10% of diet.
Source: Rufus Chaney, USDA
Phosphate Amendment Reduced
Soil Pb Bioavailability to Humans
Joplin Soils -- Preliminary Results
Group
Age Weight Pb Dose Soil Dose Bioavailability
yr
kg
µg
mg
%, Absolute
Untreated 29.6
62.2
238
45.7
42.2
(26.3-51.7)
P-Treated 34.5
72.2
261
61.5
13.1
(10.5-15.8)
Maddaloni et al., 2001; unpublished.
Effect of Depth in Soil and Distance From
Painted Wall on Pb in "Houseside Soil”
Side of House
Distance
Depth
m
cm
0-1
0-5
5-10
10-15
0-5
5-10
10-15
1050
1060
940
431
404
400
44700
20600
7270
110
2020
2110
7330
4680
3300
298
366
286
0-5
5-10
10-15
Source: Rufus Chaney, USDA
194
162
248
1940
374
2175
730
686
452
5
10
A
B
C
----mg Pb/kg dry soil----
Low Maintenance Groundcovers
• Pachysandra (Japanese
Spurge)
• Vinca Minor (Myrtle or
Periwinkle)
– thrives in wet
conditions
Groundcovers, cont.
• Hedera Helix (Baltic Ivy)
• Juniperus communis
(Juniper)
• Kentucky Bluegrass
Phytoremediation - using plants to
remove contaminants
Advantages
• Inexpensive
• Does not disrupt
ecosystem
• Low-tech, accessible
• Metals can be
reclaimed
Disadvantages
• Remediation confined
to depth of roots
• Leaching into
groundwater is not
prevented
• Time consuming
• Bioaccumulation risk
Phytoremediation Research
Lead Levels In Boston Soil
1600
1400
1200
1000
800
Lead ppm
600
400
200
0
0
6
Weeks
12
• Edenspace, corp.
reduced lead levels
by 75% on the site of
an old battery
factory in NJ in 1995.
• In Boston residential
areas, Edenspace
used Indian mustard
to reduce lead to safe
levels.
Phytoremediation Particulars
Species
• Indian and Japanese Mustard
• Brassicas
• Scented Geraniums
• Corn
• Pumpkins
• Sunflowers
• Penny Cress
• Amaranth
• Nettles
• Tomatoes
Methods
• Pre- and post- soil testing is
required. UMASS offers the
test for $9.
• Plant tissue testing is helpful.
UMASS offers this test for $14.
• Phytoremediation is aided by
use of a chelating agent (acidic
substance) to mobilize the lead.
• Without a chelating agent, one
can expect a decrease of 2025% of soil lead in six weeks.
• Plants store lead in their cell
vacuoles, especially in the roots
and shoots.
Intellectual Property Rights
• Edenspace corp. is the
leading researcher in
phytoremediation. They
hold patents for the use of
a number of
phytoremediator species.
• University of Guelf
(Canada) holds the patent
for the use of
pelargoniums for
remediation.
Phytoremediation Data 2003
Site
PreTest
ppm
3200
Action
Post Test
ppm
Pelargoniums 2500
Notes
Oberlin St.Ray
2283
Pelargoniums 2182
Oread St.
Farm
Oberlin St.
Helen
1170
Pelargonium, 910
corn
Pelargoniums 19333
4% reduction,
no paint
abatement
29% reduction
27 Oberlin St
Coes Pond
None
Visual- oil
slick
Homes/Garden 51, 231, 426
s
Rye grass
Remove oil
No actionbackground
levels
Visual- no
oil slick
N/a
22% reduction
Poisoned child
in deleaded
home
Phytoremediation Data 2004
Site
Test Plot 1Oberlin St.
Test Plot 2Oberlin St.
Test Plot 3Oberlin St.
Test Plot 4Oberlin St.
17 Community
Gardens and 1
residence
Woodland St
PreTest
ppm
Action
5782 remove sod
add 1 inch
compost
6220 remove sod
pelargorium
8in
6697 remove sod
pumpkin 8in
12845 maintain sod
and weeds
48-323 Annual
addition of
compost
20016 No actiontenant refused
Post Test
Notes
ppm
3425 41% reduction
4210 36% reduction
5388 19% reduction
11536 10% reduction
N/A
Compost
seems effective
N/A
Several failed
attempts
THE URBAN SOIL LEAD ABATEMENT STUDY
Effect of Replacing Soil With 1790 mg Pb/kg on
Blood-Pb in 1-4 year old Boston Children with
elevated Blood-Pb Levels (Weitzman et al., 1993).
Sample Time
Treatment Group
Soil+Dust
Dust
Control
------------------µg/dL------------------
Pre-Abatement
6 Mo. Post.
11 Mo. Post.
Source: Rufus Chaney, USDA
13.10
10.19
10.65
12.37
8.85
11.49
12.02
9.83
11.35
THE URBAN SOIL LEAD ABATEMENT STUDY
Soil containing 1790 mg Pb/kg was replaced.
Blood-Pb declined 0.8-1.6 µg/dL due to the
independent effect of soil replacement.
! ”... suggests that lead-contaminated soil abatement
is not likely to be a useful clinical intervention for
the majority of urban children in the United States
with low-level lead exposure.”
! Paint-Pb remains the most important source of Pb
risk to urban children in the US.
! Possible that the effectiveness of the soil abatement
may have been reduced because the children had
been exposed to high Pb soil/dust before the
abatement, and decline in Blood-Pb may not occur
as rapidly as rise upon exposure.
Other Evidence...
Aschengrau, et a. 1997. Paint hazard remediation combined
with soil abatement reduces children’s blood level 5.4 ug/dL
more than paint hazard remediation alone.
2005 Action Plan
Education:
• Organize and disseminate data
on the effectiveness of
phytoremediation field tests.
• Host 10 community workshops
on environmental health and
racism.
• Create internships for 3 college
students and work with 40
volunteers.
2005 Action Plan cont.
Direct Action:
• Create and distribute a soil
remediation kit including appropriate
seeds and safety information to 20+
residences where children have
elevated lead levels.
• Remediate three sites with
pelargoniums, groundcovers, or
organic matter.
Advocacy:
• Strengthen partnership with the City
of Worcester lead office and City
Council by working jointly on an
EPA grant.
• Work for a change in the MA lead
law so that soil lead testing and
abatement are required in children’s
yards.
2005 Action Plan cont.
Networking and Growth:
• Finalize our tax-exempt 501(c)3
status.
• Build the membership of our
organization.
• Formalize a safety protocol for
volunteers and residents doing
remediation.
www.WorcesterRoots.org
http://lists.riseup.net/www/info/worcesterroots
[email protected]
[email protected]