Weather hazard sources

The effect of increasing the capacity of the evacuation route is shown in the case of an instantaneous release scenario of acrylonitrile (600 m pool), weather class FI.5. In order to show the effect of a bottleneck, the population of the case is adjusted to a more crowded situation. The bottleneck in this example is the staircase at the end of a train platform. The platform has a length of 500 m and a width of 10 m, one end of the platform is located at 100 m from the hazardous source, the other end with the bottleneck is located at 600 m from the source. The capacity of the bottleneck is 1 person per second. The persons are assumed to start evacuation after a pre-movement time of 100 seconds. As a sensitivity analysis, the capacity of the bottleneck is increased to 2 persons per second and in another case the bottleneck is completely removed. Because the bottleneck is located at 600 m from the hazardous source and the distance to which persons will get injured is at least 810 m, all persons on the platform will at least be injured. The effect of the bottleneck in this example is visible in the number of lethal victims. In this example increasing the capacity of the bottleneck is not very effective, because the absolute reduction of the number of victims is small (see Table 4). The relative reduction of increasing the bottleneck capacity... 

Sources of lead in dust and soil include lead that falls to the ground from the air, and weathering and chipping of lead-based paint from buildings and other structures. Lead in dust may also come from windblown soil. Disposal of lead in municipal and hazardous waste dump sites may also add lead to soil. Mining wastes that have been used for sandlots, driveways, and roadbeds can also be sources of lead. 

The greatest hazard to life arises from suppression of the ability to secrete sweat, which can give rise to fatal hyperthermia if body temperature is not controlled artificially during hot weather or strenuous activity. Another source of hazard to life arises from the effect of the compounds other than scopolamine and its quaternary form in accelerating heart rate and facilitating Intramural conduction and transmission of Impulses. Ihese actions may result in serious arrhythmias up to and including ventricular fibrillation. The quaternary amine forms of the tropic acid esters in which we are interested are more active in some respects than the tertiary amines, as far as peripheral actions are concerned. This is especially true with respect to actions on nicotinic effectors in ganglia and striated muscles. The quaternary amines penetrate into the central nervous system poorly, but, once there, affect muscarinic effectors in the same way as the tertiary amines. 

Here constitutes the mean frequency of the occurrence of damage per person and unit time, provided the person in question is subject to the effective conditions WB r). With regard to this person, we must take the average over a population group which will dwell within the danger area or hazard area. The exposure times to be expected must form part of the consideration. The impressed risk field defined by fl(r) is dependent upon the conditions at the source of danger and upon general condition of the location, e.g., climate and weather, but not upon the actual population distribution there. From the density of population fi(r) we can derive the density of the population risk... 

The range and diversity of toxic materials used in process industries are large, but common toxic and volatile chemicals include, e.g., chlorine, bromine and phosgene. Large release of any of these could present lethal risk many kilometers downwind. The hazard arising from toxic releases is a function of the chemical s toxicity (obviously), the discharge rate (which will affect airborne concentration), the chemical volatility, whether Are or other heat source are present (since this may induce buoyancy and reduce ground-level concentrations), local population density, and local weather at the time of the release. 

Hazards involving normal work activities can usually be predicted by a trained IH. It is, however, very unpredictable how much airborne exposure a worker is subjected to from a particular source. Many times the same type of work conducted at one site is much different from an exposure condition at another. Inside exposures will remain more constant than outside where wind and weather conditions play a major role. For example, asbestos abatement work that is conducted in a controlled atmosphere inside should remain fairly constant if work practices such as negative air filtration are used and surfaces are wetted properly. Conversely, work on an asbestos roof on the outside, even though there is a difference in the type of asbestos, will depend more on weather conditions. Work practices such as location of the worker in relationship to the wind (up- or downstream) and how intact the shingles are as they are removed also play an important part in overall exposure. The more broken up they are the more likely an asbestos exposure will result. Although inside exposures sometimes can vary vastly with the size of an area and individual work practices, it is not usually expected to be that way. 

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