Stressor biological

The movement of biological stressors have been described as diffusion and/or jump-dispersal processes. Diffusion involves a gradual spread from the site of introduction and is a function primarily of reproductive rates and motility. Jump-dispersal involves erratic spreads over periods of time, usually by means of a vector. The gypsy moth and zebra mussel have spread this way the gypsy moth via egg masses on vehicles and the zebra mussel via boat ballast water. Biological stressors can use both diffusion and jump-dispersal strategies, which makes it difficult to predict dispersal rates. An additional complication is that biological stressors are influenced by their own survival and reproduction. 

Humans have also expanded the dimensions of their realized niche by managing the intensity of their interactions with other species. Humans control their own competitors, predators, parasites, and diseases, thereby reducing the constraints that these biological stressors exert on the realized, human niche. Humans also manage the ecological constraints of their mutualistic plants and animals such as agricultural cows, pigs, chickens, and plant crops. 

The nature of specific stressor(s) can provide information concerning the processes or mechanisms of exposure that will have to be evaluated in an ERA. Chemical contaminants introduced into the environment are naturally transported by the movements of wind and water. Certain chemicals can accumulate in organisms and be transmitted throughout complex food webs. Some organic chemicals are rapidly sorbed to soils and sediments, while others effectively remain in solution. Natural movements of biological stressors might be augmented by private and commercial transportation (e.g., cars, trucks, ships, airplanes) systems. 

Stressor characteristics form an important aspect of the risk assessment process. Stressors can be biological, physical, or chemical in nature. Biological stressors could include the introduction of a new species or the... 

Use of the framework for evaluation risks with biological stressors... 

Biological stressors include hazards such as bacteria, viruses, mold, fungus, and insect-related contaminants. 

Write a short presentation to give to a woikplace group on a particular chemical, physical or biological stressor. Include its effects, how bodily exposure can be assessed, and the eontrol measures. 

Describe and illustrate in detail control measures which can be used for three different physical, chemical and biological stressors. 

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