Pathways, Cycles: Bioaccumulation, Impact on Living Ecosystems

Abstract

Potentially toxic metals follow natural environmental pathways and cycles through the many ecosystems that provide for the very essence of life: water, food and waste disposal. To some degree they follow the geochemical cycles for the nutrients that sustain life (Figure 4–1): (O₂) supports respiratory metabolism; CO₂ is the source of carbon for photosynthesis; N₂ is an essential element of proteins; S is essential for protein and vitamin synthesis; and P is incorporated into many organic molecules and essential for metabolic energy use. Terrestrial, fluvial/lacustrine, estuarine and oceanic life forms can suffer short-or long-term perturbation if these pathways and cycles are intruded by natural events or impacted by human activities.