Indeed - "too simplistic". The sediments throughout the river are now polluted and this "internal source" would continue to affect the river even if external sources were "switched off". Furthermore, many contaminants have entered the food chain and so would persist long after "switching off" external sources. In some cases these contaminants will are likely to be endocrine disrupters and so affects are not limited to the current generation. For external sources, soils and groundwater across the catchment are also contaminated and so "switching off" point sources and even the more obvious diffuse sources would not immediately stop additional pollutants reaching the river.
Published by William Young
Indeed - "too simplistic". The sediments throughout the river are now polluted and this "internal source" would continue to affect the river even if external sources were "switched off". Furthermore, many contaminants have entered the food chain and so would persist long after "switching off" external sources. In some cases these contaminants will are likely to be endocrine disrupters and so affects are not limited to the current generation.
For external sources, soils and groundwater across the catchment are also contaminated and so "switching off" point sources and even the more obvious diffuse sources would not immediately stop additional pollutants reaching the river.