Workers gather up the topsoil in the back yard of The Church on Main. Contractors are digging up the top 6 inches of soil in the yards of many homes south of Main Street in an effort to rid the area of any possible lead contamination.

Crews in hazmat suits will be a regular fixture in the yards of Chattanooga's Southside for the next several months as the U.S. Environmental Protection Agency works to remove toxic levels of lead from soil on 68 residential properties.

The extensive project, on Read and Mitchell avenues and other areas in the Southside, is the result of the EPA's yearlong environmental investigation. The agency was first alerted to potential contamination of soil in the area last summer after at least one individual got sick.

Jane Harper, who lives down the street from where crews were working Monday, said she was alarmed when she first heard about the lead in her neighborhood.

"It's a big concern for our kids," said Harper. "We know another family down the street that actually has pretty high levels of lead in their backyard where the kids play. But I do feel like [the EPA] got on top of it."

She attended several informational meetings for residents and took her three young children to get blood tests at the doctor. All had safe lead levels.

Crews tested the Harpers' yard several times and found only pockets of toxic soil.

Her yard is just one of dozens along the residential streets that will have to be dug up.

The Tennessee Department of Environment and Conservation first evaluated the area in 2011 after a resident on Read Avenue showed up in an emergency room with lead poisoning.

TDEC and the Chattanooga-Hamilton County Health Department conducted initial tests of the yard. Lead was found in the home. Toxic levels of lead also were found in the yard.

Once crews discovered the soil in the yard was "hot" with lead contamination, they contacted the EPA.

"That indicated to us that this could potentially be more than one property," said Perry Gaughan, who is the on-scene coordinator for emergency response and removal.

After testing last fall, the EPA conducted a large-scale assessment of 82 properties in the area and found that 68 were contaminated.

The average lead levels being found in the area are from 400 to 800 parts per million, Gaughan said. The threshold for removing the soil is 800. A handful of the homes exceed 1,000.

It is unclear how the contaminated soil got there in the first place. Mining, smelting and refining over the years have led to a sizable increase in lead levels in soil, but the neighborhood is not on a former industrial site.

Gaughan said lead is only being found in the older homes around the block, and that the source could have been old fill dirt. Either way, the EPA officials say they are confident the lead is not being drawn from an active source.

"One house has it in the side yard, one house has it in their front yard or backyard. It's not all in one place," said resident Robin Hayse, whose family's front yard is the only area that needs to be replaced. "It's almost like somebody got it and brought it in."

At this point, the EPA has said the risks are enough to raise caution, not raise alarms. They are encouraging residents to wash their hands if they have been in the soil and to take off their shoes before coming into the house. Any food grown in gardens needs to be washed.

Officials say they have held one-on-one meetings with residents throughout the process and have held at least two informational meetings with neighborhood residents.

Hayse has had her three children tested and said they all had safe levels.

"Nobody I have talked to in the neighborhood is really worried or upset," she said. "We're taking precautions."

HEALTH CONCERNS

The dangers of lead poisoning have come to light in the last 20 years, according to Dr. Jennifer Keates, who is a hematologist/oncologist at T.C. Thompson Children's Hospital at Erlanger.

Children especially are vulnerable to lead poisoning. Even exposure to low levels of lead can cause damage to the brain and nervous system, Keates said.

"Blood lead toxicity between 1 and 4 years of age can seriously impair children's cognitive skills," said Keates.

The most common source of lead is from lead paint in homes built before 1978, but lead levels in soil have become a growing concern.

Just this year, the national scale of lead toxicity in children changed after researchers discovered even seemingly small amounts of lead poisoning can affect children later in life.

It used to be that 10 micrograms of lead per deciliter of blood was considered problematic. Now that number has been lowered to 5. For adults, the number is 25 -- their risks are much smaller.

The EPA has recommended residents in the neighborhood get their children's blood tested and contact the Chattanooga-Hamilton County Health Department with any public health concerns.

Tom Rucci, case management services director for the health department, said the agency has been "monitoring" the situation on the Southside, meaning the agency will receive and evaluate reports of any elevated blood lead level in children.

"There is no one we have encountered at this point who has needed follow-up care," he said.

Rucci said the concentration of lead in the neighborhood qualifies as an "at-risk" community by the standards set up by the Centers for Disease Control, so families without a pediatrician or insurance can come to the health department for a screening and checkup.

"We recommend that all children between 3 and 72 months be screened for blood lead levels," he said.

Though the neighborhood is across the street from Battle Academy, Gaughan said the soil at the school has been tested extensively and does not show any presence of toxins. Crews also reported that the soil was safe in a neighborhood playground.

The highly contaminated soil will be treated before it is taken to a landfill, Gaughan said. The lightly contaminated soil is accepted in landfills as is.

At this point, the EPA says the full cost of the soil testing and removal is unknown.

Contact staff writer Kate Harrison at kharrison@timesfreepress.com or 423-757-6673.