According to Perera, some evidence already exists that PAHs can lead to epigenetic changes in gene activity that cannot be identified by looking for breaks or disruptions in the genetic code itself.

• 裴里拉说，已经有些证据指出PAH所导致的基因活动产生外遗传变化，这些变化中并没发现有基因编码的缺失与改变。