Participants in a lead remediation workshop organized by Groundwork New Orleans got to observe soil analysis firsthand Sunday in the Earth Lab environmental classroom in a lot adjacent to the Healing Center on St. Claude Avenue.

The free workshop, “Living With Soil: Issues, Outcomes and Interventions in New Orleans,” was offered to homeowners, landlords, renters and urban gardeners concerned about lead contamination.

Dr. Howard Mielke, a research professor in Tulane Medical School’s department of pharmacology and a nationally recognized expert on soil analysis, pressed an X-ray fluorescent analyzer against various soil surfaces to get immediate readings. The spectrometer is able to quantify the presence of any element from magnesium to uranium.

The findings — as low as 51 parts per million and as high as 228 parts in an area close to a recently renovated house — showed a decisive improvement over the lead levels measured during a 2001 mapping study in the Marigny and Bywater neighborhoods. At that time, the lead level there could be as high as 1,700 parts per million .

“This is one of the most highly contaminated parts of the city,” Mielke said.

The 2001 map reflected more than 5,000 soil samples.

Earth Lab’s site has been covered by clean soil that is acceptable for urban gardening.

“We want to provide a healthy environment for the students to work in,” Alicia Neal, executive director of Groundwork New Orleans, said about high school students in the nonprofit’s Green Team program.

Mielke provided an overview of the origins of lead in the environment, its effects on health and methods to safely remediate homes, gardens, schools and worksites.

Between 1900 and 1985, lead was used heavily in paints and gasoline additives. Lead smelters in every state produced 12 million metric tons of ore, leaving a layer of lead dust in urban areas. A lead smelter in Algiers Point, for example, continues to affect the quality of West Bank soil.

Although lead was banned from gasoline in 1995, contaminated soils continue to be heavily concentrated around major highways and thoroughfares.

“During that time, we were all being poisoned by lead,” Mielke said.

Because children are predisposed to sucking their thumbs, their environments must be free of lead dust, Mielke said. Children younger than 3 are particularly vulnerable because they crawl and play on the ground around their homes.

The effects of lead exposure can include irreversible fetal brain damage, hearing problems, learning disabilities, violence, Alzheimer’s disease, hypertension, chronic kidney disease, diabetes and impaired bone synthesis.

“There are a lot of learning disabilities and people struggling to succeed in school,” said Robyn Munici, a Treme mother concerned about her toddler’s blood level.

“We are not protecting our children with the standards we have,” Mielke said. “To include a margin of safety, it should be 40 instead of 400 (parts per million).”

The Environmental Protection Agency sets a higher standard for lead safety inside the home, yet lead is constantly tracked inside houses.

Emphasis on eliminating lead inside the home has unfortunately encouraged homeowners to try to get rid of lead paint, when the best method is to paint over it, Mielke said. Modern paints can contain the lead, while dry sanding distributes it.

“Don’t even try to get rid of the lead in those old houses. Just seal it. Or go back to wallpaper, for that matter,” Mielke said.

There are two choices for growing food: move gardens outside the city, where lead levels are low, or move clean soil into the city, Mielke told the group.

Megan Bayha, who recently moved to New Orleans from Oregon, hopes to start an urban farm but wants to make sure the soil is free of lead. First, Mielke advised her, put down geotextile to create a barrier, then bring in a truckload of soil and make raised beds.

Mielke is working on a new lead map study, which he believes will show vast improvement in New Orleans. Hurricane Katrina brought in vast amounts of clean soil, and HUD replaced contaminated soil when housing projects were redeveloped.

“My dream is to change the map of the city of New Orleans,” he said.