Pollution ecosystems

Prasad, M.N.V., Phytoremediation of metal-polluted ecosystems Hype for commercialization, Russian... 

Beeby, A. 1985. The role of Helix aspersa as a major herbivore in the transfer of lead through a polluted ecosystem. Jour. Appl. Ecol. 22 267-275. 

Environmental pollutants have not been proved to be the causal agents for these disorders, but it is not possible to refute the existence of neoplasm-inducing pollutants. Thus, a rise in a neoplasm s hydrobionts (water organisms) may be associated either directly with the influence of carcinogens, or indirectly, with species evolution resulting from polluted ecosystems. 

Chiral pollutant Ecosystem component Enantiomeric ratio References... 

Air pollution can be considered to have three components sources, transport and transformations in the atmosphere, and receptors. The source emits airborne substances that, when released, are transported through the atmosphere. Some of the substances interact with sunlight or chemical species in the atmosphere and are transformed. Pollutants that are emitted directiy to the atmosphere are called primary pollutants pollutants that are formed in the atmosphere as a result of transformations are called secondary pollutants. The reactants that undergo transformation are referred to as precursors. An example of a secondary pollutant is O, and its precursors are NMHC and nitrogen oxides, NO, a combination of nitric oxide [10102-43-9] NO, and NO2. The receptor is the person, animal, plant, material, or ecosystem affected by the emissions. 

Receptors. The receptor can be a person, animal, plant, material, or ecosystem. The criteria and hazardous air pollutants were so designated because, at sufficient concentrations, they can cause adverse health effects to human receptors. Some of the criteria pollutants also cause damage to plant receptors. An Air QuaUty Criteria Document (12) exists for each criteria pollutant and these documents summarize the most current Hterature concerning the effects of criteria pollutants on human health, animals, vegetation, and materials. The receptors which have generated much concern regarding acid deposition are certain aquatic and forest ecosystems, and there is also some concern that acid deposition adversely affects some materials. 

Human civilization interferes more and more with the cycles that cormect land, water, and atmosphere, and pollution seriously affects water quahty. In order to assess the stresses caused to aquatic ecosystems by chemical perturbation, the distribution of pollutants and their fate in the environment must be investigated (see Air pollution). 

The products of human activities find their way into the environment and disturb ecosystems. Pollution has altered the surroundings to the detriment of humanity. In the last several decades, the poUutional load has increased, and its character has changed (see Water—pollution). 

Pollutant Distribution. Of particular importance for the aquatic ecosystem is the distribution of volatile substances, eg, gases and volatile organic compounds, between the atmosphere and water, and the sorption of compounds at soHd surfaces, eg, settling suspended matter, biological particles, sediments, and soils (41,42). 

An appreciation of the extent to which invertebrate species may be exposed to such chemicals comes from considering the effects of complex mixtures. In the North Atlantic ecosystem alone, hundreds of pollutant chemicals have been identified. These include metals, synthetic and chlorinated organics and polycyclic aromatic hydrocarbons. Over 300 aromatic hydrocarbons have been detected in some regions of the Chesapeake Bay, and high concentrations of PCBs have been... 

Reijnder and A. Goksoyr, in Persistent Pollutants in Marine Ecosystems, ed. C. H. Walker and R. 

The harmful effects of air pollutants on human beings have been the major reason for efforts to understand and control their sources. During the past two decades, research on acidic deposition on water-based ecosystems has helped to reemphasize the importance of air pollutants in other receptors, such as soil-based ecosystems (1). When discussing the impact of air pollutants on ecosystems, the matter of scale becomes important. We will discuss three examples of elements which interact with air, water, and soil media on different geographic scales. These are the carbon cycle on a global scale, the sulfur cycle on a regional scale, and the fluoride cycle on a local scale. 

Laboratory studies have also investigated the interaction of air pollutants and the reproductive cycle of certain plants. Subtle changes in reproduction in a few susceptible species can render them unable to survive and prosper in a given ecosystem. 

Under low-dose conditions, forest ecosystems act as sinks for atmospheric pollutants and in some instances as sources. As indicated in Chapter 7, the atmosphere, lithosphere, and oceans are involved in cycling carbon, nitrogen, oxygen, sulfur, and other elements through each subsystem with different time scales. Under low-dose conditions, forest and other biomass systems have been utilizing chemical compounds present in the atmosphere and releasing others to the atmosphere for thousands of years. Industrialization has increased the concentrations of NO2, SO2, and CO2 in the "clean background" atmosphere, and certain types of interactions with forest systems can be defined. 

The interactions of air pollutants with forests at low-dose concentrations result in imperceptible effects on the natural biological cycles of these species. In some instances, these interactions may be beneficial to the forest ecosystem. Forests, as well as other natural systems, act as sinks for the removal of trace gases from the atmosphere. 

The third category for interactions is high dose (III). The effects produced by this level of interaction can be seen by the casual observer. The result of high-dose exposure is destruction or severe injury of the forest system. High-dose conditions are almost always associated with point source emissions. The pollutants most often involved are SO2 and hydrogen fluoride. Historically, the most harmful sources of pollution for surrounding forest ecosystems have been smelters and aluminum reduction plants. 

Smith, W, H., "Air Pollution and Forests Interaction between Air Contaminants and Forest Ecosystems," 2nd ed. Springer-Verlag, New York, 1990. 

Legge, A. H., and Krupa, S, V., "Air Pollutants and Their Effects on the Terrestrial Ecosystem." Wiley, New York, 1986. 

One of the major effects of acidic deposition is felt by aquatic ecosystems in mountainous terrain, where considerable precipitation occurs due to orographic lifting. The maximum effect is felt where there is little buffering of the acid by soil or rock structures and where steep lakeshore slopes allow little time for precipitation to remain on the ground surface before entering the lake. Maximum fish kills occur in the early spring due to the "acid shock" of the first meltwater, which releases the pollution accumulated in the winter snowpack. This first melt may be 5-10 times more acidic than rainfall. 

This chapter provides orientation and an introduction to the subject of air quality. As a part of this introduction, we begin exploring the options for ensuring high quality air in the environment. The focus of this book is on industrial air pollution problems, and hence, the term environment refers to the universal ecosystem that humans live and interact in, as well as the workplace. 

Ecological Effects studies to determine the nature or extent of air pollution and acid deposition to ecosystems. 

Pollution Relating to any environmental constituent present in air or water to such an extent that it presents a hazard to the present or future health of humans or any ecosystem. 

For Further Reading J. P. Grime, Biodiversity and ecosystem function The debate deepens, Science, vol. 277, 1997, pp. 1260-1261. C. K. Fajcwski and H. T. Mullins, Historic calcite record from the Finger Fakes, New York Impact of acid rain on a buffered terrane, Geological Society of America Bulletin, vol. 115, 2003, pp. 373-384. J. Raloff, Pollution helps weeds take over prairies, Science News, vol. 150, 1996, p. 356. Environment Canada, Acid rain, http //www.ec.gc.ca/acidrain/. 

---