BIOGEOCHEMICAL CYCLING AND POLLUTANTS EXPOSURE -- ASSESSMENT OF ECOSYSTEMS RISKS -- BIOGEOCHEMICAL STRUCTURE OF ECOSYSTEMS -- BIOGEOCHEMICAL STANDARDS -- BIOGEOCHEMICAL APPROACHES TO ECOSYSTEM ENDPOINTS -- BIOGEOCHEMICAL APPROACHES TO HUMAN EXPOSURE ASSESSMENT -- NATURAL BIOGEOCHEMICAL PECULIARITIES OF EXPOSURE ASSESSMENT -- ARCTIC AND TUNDRA CLIMATIC ZONE -- BOREAL AND SUB-BOREAL CLIMATIC ZONE -- SEMI-ARID AND ARID CLIMATIC ZONES -- SUBTROPIC AND TROPIC CLIMATIC ZONE -- EXPOSURE ASSESSMENT IN TECHNOGENIC BIOGEOCHEMICAL PROVINCES -- OIL AND GAS BIOGEOCHEMICAL PROVINCES -- METALLOGENIC BIOGEOCHEMICAL PROVINCES -- URBAN BIOGEOCHEMICAL PROVINCES -- AGROGENIC BIOGEOCHEMICAL PROVINCES -- ENVIRONMENTAL RISK ASSESSMENT IN A REGIONAL SCALE -- CALIFORNIA CASE STUDIES -- EURASIAN CASE STUDIES -- CASPIAN SEA ENVIRONMENTS -- TRANSBOUNDARY N AND S AIR POLLUTION -- TRANS-BOUNDARY HM AIR POLLUTION -- TRANS-BOUNDARY POP TRANSPORT -- TRANSBOUNDARY GAS AND OIL PIPELINES. At present, quantitative ecological risk assessment is widely used in different contexts, however very often without an understanding of the natural mechanisms that drive the processes of environmental and human risk. Its application is often accompanied by high uncertainty about risk values. On the other hand, the sustainability of modern technoecosystems is known because of their natural biogeochemical cycling that has been transformed to various extents by anthropogenic studies. Accordingly our understanding of the principal mechanisms that drive the biogeochemical food webs allows us to present a quantitative ecological risk assessment and to propose technological solutions for management of various ERA enterprises. It also enables us to devise a powerful mechanism for ecological insurance, to assign responsibilities and protect rights while managing the control of damage from natural and anthropogenic accidents and catastrophes.