Air around the vent tower will be polluted to some extent by the exhaust gas from the port, so the vent tower should be heightened to prevent the building and personnel from the pollutants harm.

• 出口污染物会对距风井近距离范围内的大气产生一定程度的污染，可适当加高风井高度以使周围建筑物及人员免受污染物的危害。