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The Worcester Roots Project

Learn about lead contamination, health effects, and legal aspects of soil lead remediation. Explore ways to reduce exposure and promote phytoremediation for healthier communities.

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The Worcester Roots Project

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  1. The Worcester Roots Project Using Plants to Repair the Soil

  2. Introductions 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 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 Workshop Outline

  3. 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.

  4. 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).

  5. 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.

  6. RISKS FROM EXCESSIVE CHRONIC DIETARY LEAD • Most Important Soil-Pb Risk is to Children: • Children absorb a higher fraction of dietary Pb. • Children are more exposed due to hand-to-mouth play. • Health Effects from Excessive Absorbed Pb: • US Geometric mean for children, 2002 3.5 µg/dL • Neurobehavioral Impairment > 10-15 µg/dL • I.Q. Reduction; behavior problems. • Hearing loss. • Balance instability. • Interfere with enzymes; anemia. > 40 µg/dL • . . . • Encephalitis. >100 µg/dL • Death.

  7. 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.

  8. Nation at Risk, cont. • Over 80 percent of all homes built before 1978 in the U.S. have lead-based 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.

  9. 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.

  10. UGROWUrban Garden Resources Of Worcester, a project of theRegional 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)

  11. 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.

  12. 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.

  13. 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. There are no state regulations requiring soil testing or remediation. Photo Source: “Reducing Children’s Risk from Lead in Soil” Ryan et al. 1/1/04 Environmental Health and Technology

  14. 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.

  15. 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

  16. Source: Samantha Langley-Turnbaugh, Univ. Southern Maine

  17. Source: Samantha Langley-Turnbaugh, Univ. Southern Maine

  18. Source: Samantha Langley-Turnbaugh, Univ. Southern Maine

  19. Source: Samantha Langley-Turnbaugh, Univ. Southern Maine

  20. 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 Pb-disease compared to suburban children. Source: Rufus Chaney, USDA

  21. 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 N=6 yrs kg µg mg % Fasted 28 59.7 213 72.926.2(18.0-35.6) Fed 28 67.9 242 82.92.52(0.2-5.2) Source: Rufus Chaney, USDA

  22. 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%.

  23. 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 .

  24. 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

  25. 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 no-effect level of 300 mg Pb/kg dry biosolids fed at up to 10% of diet. Source: Rufus Chaney, USDA

  26. 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 45.742.2 (26.3-51.7) P-Treated 34.5 72.2 261 61.513.1 (10.5-15.8) Maddaloni et al., 2001; unpublished.

  27. Effect of Depth in Soil and Distance FromPainted Wall on Pb in "Houseside Soil” Side of House Distance Depth A B C m cm ----mg Pb/kg dry soil---- 0-1 0-5 1050 44700 7330 5-10 1060 20600 4680 10-15 940 7270 3300 5 0-5 431 110 298 5-10 404 2020 366 10-15 400 2110 286 10 0-5 194 1940 730 5-10 162 374 686 10-15 248 2175 452 Source: Rufus Chaney, USDA

  28. Low Maintenance Groundcovers • Pachysandra (Japanese Spurge) • Vinca Minor (Myrtle or Periwinkle) • thrives in wet conditions

  29. Groundcovers, cont. • Hedera Helix (Baltic Ivy) • Juniperus communis (Juniper) • Kentucky Bluegrass

  30. 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 - using plants to remove contaminants

  31. Phytoremediation Research • 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.

  32. 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 20-25% of soil lead in six weeks. Plants store lead in their cell vacuoles, especially in the roots and shoots. Phytoremediation Particulars

  33. 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.

  34. Phytoremediation Data 2003

  35. Phytoremediation Data 2004

  36. 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 13.10 12.37 12.02 6 Mo. Post. 10.19 8.85 9.83 11 Mo. Post. 10.65 11.49 11.35 Source: Rufus Chaney, USDA

  37. 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.

  38. 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.

  39. 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.

  40. 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.

  41. 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.

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