Threshold and dose response estimation using the “filter model”

The “filter model” has been developed to explain the biologic effects of radiation and chemicals. We have examined nearly 300 sets of dose response data, of which 50 are presented here. Responses (induced by radiation and chemicals) which have been examined include in vitro survival studies on animal and plant tissues, induction of cellular aberrations and time to tumor or death. Similar data from in vivo studies has also been examined. All of the data appear to fit the model R = a lnD + b(lnD)² + c, where R is the response, a and b are parameters fitted by regression to a particular set of data, and c is the response at zero (or lowest) dose. By writing this model in exponential form, it can be seen that the response R results from multistage filtering (by net amounts a and b) of the initial dose, D. The threshold is obtained from this model as the point, $\text{D}\text{?}{}_{\mathrm{T}}$, at which the second derivative becomes zero. This is given by $\text{D}\text{?}{}_{\mathrm{T}}\text{=}\text{exp}\text{(1 ?}\text{a}\text{2b}\text{)}$ when a and b are oppositelt signed.     

International competitive displacement from environmental control The quantitative gains from methodological refinement

This paper demonstrates empirically the gain from adopting more general equilibrium approaches in projecting the effects on domestic output and international trade of environmental controls. The suggested models include a partial equilibrium case where all industries are treated independently, an intermediate case incorporating effects in supplying industries, and general equilibrium formulations based on alternative macroeconomic conditions. U. S. data is used to evaluate these models. Under both pollutor pays and subsidy financing schemes, moving from the simplest case to the intermediate model results in quite different industry projections. Including macroeconomic factors appears particularly important in the classical setting.     

The 'who' and 'what' of training far disaster relief

This paper defines the various levels within government, the voluntary agencies and the community which might benefit from training and makes suggestions as to where the emphasis should be placed. It points out that training programmes should be designed to meet the expressed needs of a particular group of trainees as well as be related to the current or potential disaster situation.     

Permanent post-disaster housing in honduras: aspects of vulnerability to future disasters

To some degree it is unfair to evaluate a post-disaster housing program as to its effectiveness in decreasing vulnerability and preventing future disasters. As Burton states, "With rare exceptions, administrators and techniques have been trained to cope with disaster rather than to prevent it" [reference (2), p.197]. These were certainly not goals articulated by the agency responsible for constructing housing after Fifi. However, the authors feel that failure to evaluate specific projects by persons knowledgeable of the projects functioning, will only forestall the shift which Cuny calls for, "… from disaster response to disaster mitigation and prevention" [reference (4), p.123). In doing this we hope to add some specific case study data to the growing literature on disaster mitigation and prevention. Disaster vulnerability in Honduras is overwhelmingly related to flooding. More crucial than the materials and construction of housing is the issue of siting. If appropriately sited, houses made of bajarique, wood, or concrete block are able to withstand the heavy rains associated with a hurricane. Regarding the siting of the projects, the Honduras Project clearly has one positive and one negative accomplishment in the cases of Santa Rica and Flores, respectively. San Jose is less clear but is certainly a much safer site than those formerly occupied by the residents, in that there is no danger of flooding. The present site was not flooded during Fifi nor did it experience mudslides. However, the future is not so clear regarding the latter. Within the village proper a large amount of vegetation has been added which will tend to stabilise the soil on the steeper slopes. The streets, however, are seriously eroded and probably can not be maintained for vehicle usage, which does not pose a serious problem to the residents as none possess automobiles or trucks. One large gully bisects the village and receives run-off from the adjacent hills. It has been expanding, which would suggest that the slopes above the village could prove problematic in case of a Fifi-sized storm. Flores is located on a very poor site in reference to prevention and mitigation. It is located in a portion of the Sula Valley which is prone to flooding and, as mentioned before, was inundated by over 2m of water during hurricane Fifi. No prevention techniques were possible by NAEA/HEA and the houses were built on earthen mounds barely adequate to keep water out during the rainy season. The nearby dike which could possibly provide protection is non-functional due to poor maintainance. Given a storm of Fifi's magnitude, or possibly smaller, this site will again be flooded. Santa Rica is clearly well sited concerning flooding: it did not experience flooding during Fifi and is not flood prone. However, houses did experience some wall damage due to earthquakes following and associated with the Guatemalan quake of 1976. Due to the size and nature of the latter much "re-adjustment" occurred in the neighbouring fault system; however, damage to the houses was all superficial. We feel the residents were vocal about their concern due to the severity of the Guatemalan disaster and their lack of experience with concrete block houses. That the two sites (particularly Flores and partially San Jose) are vulnerable to future disasters cannot be considered solely the fault of an outside agency without local knowledge and understanding. In the engineering report issued during the construction it was explicitly stated that in Flores, "Future flooding remains a danger," [reference (6), p.49]. The future residents of Flores had gained access to the land from the National Agrarian Institute and were anxious to receive assistance in building homes. In fact, CARE, which had previously given these people tin roofing for houses, was threatening to take it back since the people had not yet started building. NAEA/HEA were responding to people in a rather desperate situation. But, on the other hand, they were responding to people who had been promised (not given) land by an agency of the Honduran national government which would be cognizant of the potential flooding at this site. Likewise, in San Jose, where mudslides and erosion remain a threat, the land was provided by a local government agency, the municipality. Although our goal in this discussion has not been to establish blame, we feel it imperative to mention the sequence of events that resulted in the questionable siting of Flores and San Jose. It is very easy and often accurate to place blame on outsiders who lack sophistication and knowledge about such matters. In this case local input did not result in post-disaster planning that is actually precautionary. This, we feel, illustrates the extreme complexity of cross-cultural aid, especially in the post-disaster period. It also points to the need for precautionary planning with reference to permanent post-disaster reconstruction.