BEVERLY HILLS ( — Students at Beverly Hills High started their first day of the school for the fall semester Tuesday after arsenic was discovered on campus.

Principal David Jackson stood in front of the school welcoming students back to class, answering questions and addressing concerns. “If there were any health concerns to the students, we would not have them on campus,” he said. “You’d rather be over safe than sorry.”

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But the lacrosse field was off-limits as it was fenced off and secured with padlocks. On Friday, state officials found that soil samples taken from where construction was about to get underway contained levels of arsenic over the acceptable limit. Additional tests were also conducted in other areas of the campus.

The soil samples were part of a series of environmental tests being done ahead of major construction planned for the 100-year-old campus.

The school told CBS2/KCAL9 that it emailed parents informing them that five areas on the lacrosse field had arsenic levels exceeding state standards. And the highest level of the cancer-causing compound was found just feet beneath the surface.

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Parents have mixed reactions to the possible health risks. “They’re not toddlers, you know, little kids that are crawling and doing things like that,” said parent Paria Hassauri. “Although certainly, you know, I can understand that you don’t want them playing lacrosse.”

Student Samy Al-Majar said: “If it’s a safety hazard, I’d rather have it taken care of now than later on. We have to learn the hard way,” he said.

Arsenic occurs naturally all across the Los Angeles basin. The compound can also come from pesticides. Exposures to high levels are known to cause health problems such as cancer.

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The school district is awaiting full results of the tests. It said the lacrosse field will remain closed until the problem is resolved.