To say it aloud would be to make it final, absolute, irretrievable.

如果大声地说出来，就会使这件事彻底终结，彻底法回了。

His heart was full, and his conscience tortured by remorse; for he accused himself more bitterly than ever of being the cause of the irretrievable disaster.

这次可回的祸事使他的心很沉重；他的良心深感不安，他不住地在怨恨自己。

Untold tonnes end up as irretrievable ocean flotsam, which sunlight and salt fragment into microscopic pieces that attract toxins and may be gulped by creatures that become seafood.

数吨塑料最后变成了法清理的海洋漂浮垃圾，在日光和盐分的作用下破裂成会吸附毒素的微小碎片，可能会被海洋生物吃掉，最终又上了我们的餐桌。