Metal pollution anthropogenic inputs

Surface water enrichment is the result of aeolian and fluvial inputs, which are thought to be the most important sources of Th to the ocean. Thorinm-232 has been proposed as a link between the radiogenic thorium isotopes and trace metals and anthropogenic pollutants. " While the pathways are very different for the radiogenic thorium isotopes, Th is delivered to the ocean in a fashion similar to many pollutants and trace metals. For example, Guo et found Th distributions in the Gulf of Mexico and off Cape Hatteras in the North Atlantic Ocean agreed well with the general distribution pattern of aluminum. 

Because of their position between the upland drainage and the sea, it is reasonable to suppose that estuaries have always been subjected to appreciable loadings of nutrients and other weathering products from their watersheds. However, various other features of estuaries (fisheries, commerce, etc.) have also long made them attractive for human settlement, with the result that a far larger anthropogenic input of nutrients, heavy metals and other pollutants has often been superimposed on an already rich background. 

The biohazard in soils attributable to heavy metals, and to metalloids such as arsenic, has often been assessed by determination of their total soil contents and national guidelines based on such total contents are currently in use (see for example, Appendices 3-6 in Alloway, 1995). Total soil contents, however, reflect the geological origins of soils as well as the anthropogenic inputs such as pollutants from industrial processes and are poor indicators of mobility or bioavailability. A more relevant assessment of the contents of elemental contamination can be made by measuring the pseudototal element contents of a soil by the... 

Lee et al. (2006) use both PCA and CA to determine metal associations arising from anthropogenic input to the soils of Hong Kong. The analysis identifies Cu, Pb and Zn as the main elements responsible for pollution in the area. The author uses the data to calculate and map the distribution of a soil pollution index (SPI), which is indicative of the traffic impact on the urban territory (Fig. 8.8). 

Anthropogenic Trace Elements in the Ocean. Atmospheric Input of Pollutants. Carbon Cycle. Conservative Elements. Hydrothermal Vent Fluids, Chemistry of. Marine Silica Cycle. Metal Pollution. Nitrogen Cycle. Platinum Group Elements and their Isotopes in the Ocean. Refractory Metals. River Inputs. Transition Metals and Heavy Metal Speciation. 

High proportions of mobile Cu and Pb have been reported in polluted soils by others (Me Bride 1989 Kocialkowski 1991 Zieien and Bruemmer 1991 Greinert 1993), suggesting that anthropogenic input of metals may contribute essentially to the total available metal pool, from where these metals may move downward in soil profile. However, this assumption seems to contradict the empirical observation for the stability and immobility of lead in soils. ... 

The AYRSSM allows us to estimate the dependence of pollution level in the AYRS estuary as a function of anthropogenic activity. Suppose that the intensity of sources of heavy metals is such that their concentration in the water near Angarsk, Irkutsk, Krasnoyarsk, Bratsk, and Ust-Ilimsk can be described by a stationary function, supporting heavy metal concentrations at level h at each of these cities. Computer experiments show that there is a stable correlation between h, the heavy metal concentration in the AYRS estuary, and the water flow rate fi. An increase in h of 10% leads to a rise of pollution input to the Kara Sea by 2.5%. An increase in h of 1% leads to a rise of pollution input to the Kara Sea by 0.7%. These results are correct only when variances in values fi and h are close to their average estimates. Near their critical values the estimates are unstable and more detailed models are required. 

A differentiation between natural and anthropogenic heavy metal loads into the Baltic is not possible because metals are also natural components of the earth s crust. Taking into consideration that the HELCOM database is stiU incomplete, a general reduction of the total metal load was calculated for Hg ( 74%), Pb (< 66%), Cd ( 62%), and Zn ( 9%) between 1990 and 1995. For Cu, an increase of 13% was estimated. With the addition of the trace metal input data from the fourth pollution load compilation, the situation changed drastically. Compared to 1995 (HELCOM, 1998), the total heavy metal loads increased by a factor of -3 for Cd, 4 for Pb, and 9 for Hg in 2000 (HELCOM, 2004,2005), while for Cu (0.7) and Zn (0.8) a decrease of the river loads was estimated. The heavy metal export into the North Sea is of circumstantial relevance in relation to the total metal load entering the Baltic Sea (Dippner and Pohl, 2004). 

Alterations in trace metal concentrations in the marine environment due to man s activities are difficult to establish, since natural levels are often poorly known, or when known show variations. At present, measurement of concentration gradients (both vertical and horizontal) from known pollution sources is the primary method to assess trace metal contamination of the marine environment. High trace metal inputs into estuarine or coastal areas from industrial effluents as well as from river run-off have been measured. Without knowledge of the make-up of these source materials, distinguishing between a natural and an anthropogenic origin for increased metal concentrations is an insoluble problem. 

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