The new campus of a primary school in Shandong was accused of having a pungent smell and some students had nosebleeds. The Education Bureau said that the formaldehyde test was qualified. What could be the cause? What responsibilities does the school have?

山东一小学新校区被指气味刺鼻，有学生流鼻血，教育局称甲醛检测合格，可能是什么导致的？校方有哪些责任？

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