求翻译：由环境污染衍生的环境效应具有滞后性，往往在污染发生的当时不易被察觉，然而一旦发生就表示环境污染已经发展到相当严重的地步。是什么意思？

Derived from the environmental effects of environmental pollution with a lag, often occurring in the pollution was not so noticeable, but it has occurred that environmental pollution has been developed to a very serious stage.

Environmental pollution by derivatives of the environmental effects have lagged behind in pollution, often at the time of occurrence is not readily detectable, however once it has occurred that environmental pollution has reached a very serious stage.

The environment effect grows which by the environmental pollution has the hysteresis quality, often occurred in the pollution at that time not easily was realized, once however occurred on the expression environmental pollution already develops the quite serious situation.

Environment derived from environmental pollution effects have lagged often pollution occurred was easily detectable, however event that pollution has grown to considerable proportions.

By the derivative of the environmental effects of environmental pollution has lagged, often in pollution occurs when not being seen, but when it does happen that environmental pollution has been developed to a considerable level.