The area where the arsenic level was the highest in the top two inches of soil in the park was the sand box, WET’s sample results show.

The highest level of lead came back, at 1,118 parts per million, at a depth of two to six inches, just under a tree in the middle of the park.

The highest arsenic level in the park, at 1,285 parts per million, at a depth of six to 12 inches, is in the sand box.

Arsenic is a known carcinogen. Lead exposure in children can cause learning and behavioral problems, brain damage, developmental delays and other physical and mental problems, according to EPA’s website. Although lead exposure is a concern for people of all ages, young children, from newborn to seven years old, are the most at risk.

EPA has determined that safe levels of arsenic in the soil for Anaconda is 250 parts per million and safe levels of lead are 400 parts per million in the soil. EPA says it based those levels on laboratory tests. But critics of EPA’s cleanup in Anaconda point out that the Smelter City has one of the highest levels for arsenic at Superfund sites across the nation.

EPA’s level of 400 parts per million for lead in Anaconda is “generally considered an appropriate screening level for soil lead,” according to EPA’s website.