The West End Soil Remediation Project

By: Samantha Langley-Turnbaugh, Department of Environmental Science, School of Applied Science, Engineering and Technology and Lisa Belanger, City of Portland, Public Health Division

Funding provided by Environmental Protection Agency Health Communities Program

Every year over 1,000 children in Maine are identified with elevated blood lead levels (5.5 ug/dl versus the national average of 2.7 ug/dl) and Medicaid recipients in Maine are twice as likely to be lead poisoned. In Portland, only 22% of the children under 6 years old have been screened for lead poisoning- 5.9% have blood lead levels between 10-19 ug/dl and 2.3% have levels > 20 ug/dl. Lead poisoning research suggests that the primary sources of lead exposure for most children are: deteriorating lead-based paint, lead contaminated dust, and lead contaminated residential soil. Considerable attention has been given to lead paint hazards in homes; less attention has been paid to lead contaminated soil that surrounds these homes. Generally this has been because of the more significant contribution to lead poisoning in children made by deteriorating lead paint and leaded dust on the interiors of homes. However, as lead poisoning rates and average childhood blood lead levels decline, lead exposure from soil, and from produce grown in these soils, may be a more significant portion of the exposure for children. Therefore, the soil in yards of inner city homes is potentially a major contributor to lead poisoning in youth, and is largely unregulated.

Contamination of soils by heavy metals has been widely described in urban areas. However, limited data exist regarding metal mobility in residential soils and their accumulation by plants grown for human consumption. Many backyard and community gardens are established on sites that are unsuitable for other purposes, and that may be contaminated with a high content of heavy metals. And, whereas most community gardens are tested annually, backyard gardens are not. In general, plants do not absorb, or accumulate lead, so it remains in the soil at elevated levels. However, in soils testing high in lead, it is possible for some lead to be taken up by plants. Urban gardens may supply an extraordinarily high proportion of vegetables in diets of low-income persons, and members of the immigrant and refugee community who are without adequate access to vitamin supplements, nutritional variety and basic health care. These citizens may also suffer disproportionate environmental risk due to their low economic and socio-political status. Despite the risk, contaminated garden sites and inexpensive fertilizers may be the only option for these citizens to supplement their diet with familiar crops and cultural comfort food. Risk guidelines are needed to assist citizens in using urban soils for gardening, and to allow residents to actively participate in managing their health.

Portland’s West End neighborhood has a population of over 8,000 residents. Eighty-eight percent of the children that attend the Reiche Elementary School, located in the heart of the West End neighborhood, are eligible for free or reduced lunch subsidy. In addition, approximately 60% of the Reiche school population is ethnic minority students, half of which have limited English proficiency. The area was developed after Portland’s “great fire” in 1866, and approximately 84% of the housing was built before 1950. The West End remains today as one of America’s best-preserved Victorian residential neighborhoods, and was entered on the National Register of Historic Places in 1982. Also, beginning in the early 1700s the West End was home to a variety of industries including a large tannery, a railroad equipment manufacturer, planning & plaster mills, a copper shop, a cement pipe and stone company, and a glass company. The West End also housed the Maine State Arsenal, and included an active waterfront – with many commercial wharves served by a railroad terminal. Thus, lead poisoning is a great concern in the West End neighborhood, and cases of severely poisoned children have been identified there. Traditionally, most concern has focused on the lead-based paint in houses, with less attention given to the accumulation and mobility of lead in yards that serve as play areas, pet quarters, and home gardens.

Therefore, the goal of this project is to help the residents of the West End protect their children from the dangers of lead poisoning by identifying areas with contaminated soils and working with residents to remediate these soils. Specifically, we

  1. perform lead testing on urban residential soil in the West End neighborhood in Portland, Maine;
  2. test native vegetation growing on-site to determine the potential for native species to accumulate lead, and apply a low cost, in-situ mitigation technique (phytoremediation) using food source plants to remediate lead contamination in backyard gardens; and
  3. deliver two community educational forums and disseminate informational materials to increase public awareness of lead poisoning and the project specifically.

Thus far we have sampled and analyzed 642 soil samples from 49 residential yards in the West End. Soil lead levels range from 36 to > 25,000 mg/kg. (Maine Department of Environmental Protection permissible levels are 375 mg/kg). We also found elevated chromium levels in several areas. Four sites were chosen for phytoremediation gardens. Soils were sampled in garden areas and the sites were planted with Spinacia oleracea (hybrid spinach) in May 2005. These gardens will be harvested in early July 2005, and both the spinach and soils will be analyzed. We also sampled native vegetation and perennials growing in the garden areas to assess their ability to take up lead. The remainder of summer 2005 will be spent analyzing soils, spinach and native vegetation. In previous research projects in the Bayside and Parkside neighborhoods, soil lead concentrations decreased by as much as 100 mg/kg in a single, 6-week growing season.

West End residents have been provided with maps of their property showing locations of soil sample collections, and soil lead levels. They have also been provided with a variety of brochures, translated in 9 different languages, that include guidelines for soil lead safety and low-tech solutions for remediating lead contamination in residential areas. The City of Portland has also organized and hosted 2 community forums centered on educating residents, especially the parents of young children, about the health hazards associated with lead in soils and plants. These events also serve as an opportunity to emphasize the importance of lead poisoning prevention and lead screening, and encourage participation in the City of Portland’s Lead Safe Housing Program.

This project is the third year of a collaborative venture between USM and the City of Portland Public Health Division. The success of this collaboration strengthens the growing relationship between the City of Portland and USM, and is an important component of this project. Equally important is the work of several undergraduate students in the Department of Environmental Science that have served as research assistants on this project. The success of this project is due, in large part to their work in the field and laboratory. EPA funding has allowed us to provide the students with a valuable research and community service opportunity.