New dirt to remedy playground toxins
Parts of the playground at Progress Elementary will be dug up next spring and diluted with fresh dirt after a recent study found levels of arsenic and lead exceeding state limits in the soil.
Because grass, asphalt and other materials cover the contaminated soil, health officials say the risk of students being exposed to the chemicals is remote. But samples in a statewide study of former orchard sites show that some of the soil must be blended to meet levels outlined in state environmental laws.
“The students at the school are in no danger,” said Mike LaScuola, of the Spokane Regional Health District, who is managing the project.
Gravel around the play equipment and the infield in the baseball diamond comes from material that was brought in and is not contaminated, he said. Underneath, though, testing shows the residue of an insecticide popular in the first half of the last century that contained the two heavy metals.
The limit for arsenic in soil at schools in the state’s Model Toxics Control Act is 20 parts per million. The high end of samples at Progress ranged from 69.8 ppm to 86.4 ppm, LaScuola said.
The limit for lead is 250 ppm, and samples at the school that were above the limit ranged from 289 ppm to 440 ppm.
Testing conducted at other schools and parks in the West Valley and Central Valley school districts built on former orchards did not indicate contamination, LaScuola said.
Arsenic is lethal in large doses, and long-term exposure is associated with several forms of cancer and other diseases.
Lead exposure is associated with various nervous system problems, damage to other organs and increased cancer risk.
Children age 6 or younger are most at risk for lead or arsenic poisoning from soil contamination because more dirt winds up in their mouths. Particles of lead must be eaten or inhaled for the metal to enter the bloodstream. It is also possible for arsenic to be absorbed through the skin.
The cleanup at the elementary, 710 N. Progress Road, will involve removing the grass in the contaminated areas and using a large machine to churn up the ground and mix in clean soil.
“Our intention is to start the remediation as soon as school is out,” said Central Valley School District spokeswoman Melanie Rose.
The school learned of the testing last spring. The mixing was originally scheduled for summer, but officials opted to hold off for a year so summer school and other activities at Progress wouldn’t be interrupted, she said.
Grant money from the Department of Ecology will cover the cost of remediation as well as putting sprinkler equipment back in place and replacing the grass, Rose said.