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by Linda M. Ameroso and Charles P. Mazza
Taking lead into the human body can be a serious health problem. In the urban environment, young children, pregnant women, and nursing mothers can be exposed to lead from many different sources.
While it is less apparent outside our cities, lead might still be present in particular situations. Parents who garden and youth leaders often find themselves wondering if their activities further add to the many situations that can increase lead intake for children.
Lead particles may be found in and around gardens from two sources: from the air and from the soil. The following safety measures can be used as guidelines for those concerned.
For air-borne lead particles:
Lead can land on the leaves of any garden plant from the air. The farther away the garden is from the source of air-borne lead, the less likely the lead particles can reach the garden.
A 1 % vinegar solution means 1 part vinegar to 99 parts water which is equivalent to approximately 1 tablespoon of vinegar dissolved in 1 1/2 quarts of water.
- Whenever possible, select your garden site away from a heavily trafficked highway or street.
- Erect a fence or hedge to shield vegetables from movement of lead particles in the air.
- Wash all vegetables, including those that are leafy (spinach, lettuce, cabbage, swiss chard, collards) with a 1 % vinegar or 0.5% dishwashing liquid solution. Rinse with clear water. Research in 1982 by Cornell University Urban Horticulture Institute has shown that lead particles on the outside of plant parts are easily removed by this method.
A 0.5% dishwashing liquid solution uses approximately 1/2 tablespoon dishwashing liquid dissolved in 1 1/2 quarts of water.
For soil-borne lead particles:
If your garden site may have been the site of a pre-World War II building which was demolished, paint chips from the rubble may have entered the soil. If your garden site is next to a building where lead-based paint was applied and scraped, paint chips may have landed in the garden soil.
Lead-based paint was also used on the foundation walls of pre-1950 homes and
outbuildings, and may be risky as the old exterior house paint. The lead dust from the foundation paint washed off in rain storms and became
concentrated in the top inch or two of soil at the base of the building.
Any garden located very close to heavily trafficked roads may also have a high lead content that has built up over the years.
A soil test for lead concentrations can tell you if lead is present in high quantities.
When gardening in lead contaminated soils, safety measures should be taken.
Parents should be aware that the NYC Health Department has a blood lead screening program for children. Health Departments in other parts of the state may have similar programs.
- Wear gloves, or wash hands thoroughly after gardening and especially before eating, and be sure small children do not eat garden soil. Gardeners can bring lead-contaminated soil into the house on shoes and clothes, increasing levels of lead soil and dust in the home. This is especially a concern for crawling toddlers and infants. Remember that children tend to be at a greater risk of lead exposure from soils when the soil is directly taken into the body.
- Plants may absorb some of the lead present in soil through their roots. Any lead that is absorbed tends to concentrate in leaves and the outer part of roots, so peel root crops such as beets, carrots, turnips, and radishes before eating.
- Grow vegetables that produce edible fruits such as tomato, peppers, cucumber, squash, etc. Lead absorption into plants does not concentrate in the fruits.
- If your soil has a lead contamination problem, grow fewer edible fruits and vegetables and more flowers, trees and shrubs.
Any child under the age of six with a history of elevated blood lead concentration should not eat leafy vegetables or root crops known to have been grown near a heavily trafficked road or lead contaminated soil, especially those grown in New York City.
Research at Cornell University Urban Horticulture Institute found that a soil high in organic matter with pH between 6.5 and 7.0 does a better job of binding lead in the soil, preventing it from being absorbed by any plants. The best organic matter to use is well rotted manure or compost at a ratio of one shovel-full of organic matter to 3 shovels full of garden soil. (More information on using organic matter in the garden.)
Additional resource: Case for Caution: Recommendations for Land Application of Sewage Sludges and An Appraisal of the U.S. EPA's Part 503 Sludge Rules, by Ellen Z. Harrison, Murray McBride, and David R. Bouldin, Cornell Waste Management Institute Working Paper, 1997. Posted on website http://cwmi.css.cornell.edu/PDFS/LandApp.pdf
Where you can call for help
Private laboratories will test your soil for lead and soil pH for a fee. For a list of laboratories in New York State that have been certified to perform environmental analysis which include soil testing, contact:
New York State Department of Health (518) 485-5570
Cornell Nutrient Analysis Laboratory
at Cornell University in Ihaca, New York offers soil tests for lead and most other heavy metals. They also offer soil nutrient analysis tests which include testing for soil pH and soil organic matter content.
For more information write or call:
Cornell Nutrient Analysis Laboratories
804 Bradfield Hall
Ithaca, NY 14853 (607) 255-4540
For a list of private laboratories in New York State that have been certified to perform environmental analysis, or for more information about water testing, contact:
New York State Department of Health (518) 485-5570
Safe Drinking Water:
For information about lead in drinking water, call:
Safe Drinking Water Hotline
Lead and Other Concerns:
For more information on lead and other environmental health concerns, New York State residents can call:
Environmental Health Infoline
a service of the New York State Department of Health - Center for Environmental Health
No endorsement of products or companies is either intended or implied.
Originally prepared for the Urban Horticulture Program in New York City,
Rev. 4.98 in NYC, Modified for NYS 6.00
Based on "Reducing the Lead Uptake in Lettuce" by Dr. Nina Bassuk, HortScience Vol 21 #4, pgs. 993-995. 1986.
© Copyright, Department of Horticulture, Cornell University.
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