Tehlikeli maddelerle oluşan zarar derecesinin hesaplanması

Abstract

Bu çalışmada tehlikeli maddelerin endüstriyel kullanım veya taşınımları sırasında bulundukları çevreye ve nüfusa olan tehlike potansiyelleri incelenmiş ve İstanbul ve çevresi için karayolu ve denizyolu taşımacılığı ile endüstriyel kullanımdan kaynaklanacak "nüfus zarar endeksleri" ve "çevresel zarar endeksleri hesaplanmıştır. Ayrıca geliştirilen dört adet kaza senaryosu için birer "maksimum felaket potansiyeli" belirlenmiş ve buna göre böyle bir durumda öncelikli olarak boşaltılması gereken alanlar saptanmıştır. Birinci bölümde, çalışmanın anlamı, amacı ve kapsamı kısaca özetlenmiştir. İkinci bölüm tehlikeli maddelerle ilgili detaylı bir literatür araştırmasını kapsamaktadır. Konuyla ilgili kavram kargaşasının giderilmesi için gerekli tanım ve açıklamalar verilmiş ve gelişmiş ülkelerdeki uygulamalara değinilmiştir. Üçüncü bölümde, Kanadalı bilim adamları tarafından geliştirilen ve tehlikeli maddelerin çevreye ve nüfusa olan zarar potansiyellerini belirleyen sistem açıklanmıştır. Sözkonusu sistemin İstanbul boğazı ve çevresi için uygulanması dördüncü bölümün konusunu oluşturur. Bölgedeki endüstrilerin, karayolu ve denizyolu taşımacılığının nüfus ve çevresel zarar endeksleri belirlenmiştir. Son bölümde modelin ve bulunan sonuçların değerlendirilmesi yapılmış ve bunların ışığında gerek modelin duyarlılığının geliştirilmesi gerekse incelenen bölgenin tehlike potansiyellerinin azaltılması amacıyla bazı önerilerde bulunulmuştur.

In general terms a hazardous substance is defined as a material with a substantial potential to pose a danger to living organisms, materials, structures, or the environment. Such dangers may consist of explosion or fire hazards, corrosion, toxicity to organisms or other detrimental effects. These substances may be acutely toxic or have long-term chronic effects, even at low concentrations. They include a large number of organic compounds, and a number of inorganic substances, heavy metals, for instance. Hazardous substances present a long-term and growing problem which must be dealt with. Millions of hazardous substances are transported daily along the highways, railways and waterways. Some of these substances, such as cyclic pesticides, cyanide, organometallic compounds, and heavy metals are highly toxic to man and the environment, and the accidental release of even small volumes of such materials to the environment can have serious consequences. Accidental spills and releases of hazardous substances can result from a variety of causes including highway, rail, water, industrial plant upsets, the failure of retaining dikes, storm damage, malicious acts and even air accidents. The cost of returning the environment to an acceptable state following a spill may involve the expenditure of big costs, and even after toxicants have been removed from a spill area, undesirable effects may linger the environment for many months or years. A spill can occur at a plant during a processing or loading operation or in the field during the transit of materials. Facilities to cope with emergencies are often more readily available in plants than in the field. During field spills, a good deal of damage might be caused to the environment before containment and treatment procedures begin. During an emergency involving a spill, one must assess: 1. The volume of hazardous substance released to the environment and the rate of leakage still in progress, XI 2. What danger exists to personal in the area, 3. The nature of the damage and what repairs might be attempted, 4. Whether transfer to an alternative container is advisable, 5. Whether some form of dike should be constructed, 6. The nature of the spill area and how the released substance has spread over the area, 7. Whether the spilled substance can reach or has reached a watercourse or sewer, 8. The danger of explosion and fire, 9. What effect rain and wind will have on the spill, and 10. What equipment and supplies are necessary to confine the substance and carry out the necessary treatments. Hazardous substances that enter a waterway either directly or by way of ditches or a storm sewer can produce a number of undesirable effects including fish kills, upsets in the natural flora and fauna of the aquatic environment, rendering the water unsuitable for consumption by man and animals, damage to recreational facilities, and the creation of a fire or air-pollution hazard. Spilled material that flows into a sanitary sewer can produce serious consequences with regard to the functioning of aerobic and anaerobic digestion processes at a sewage treatment plant. The safety of the human population of the area and containment of a spilled substance are of the first priority. In this study a community rating and evaluation system developed by University of Western Ontario, Canada to fine population and environmental hazards in a community so that index or an indicator of a toxic spill crisis might be calculated has been described and applied for The Bosphorus and its environment for a certain area. The system defines a population and environmental rating scheme and a maximum disaster potential index. Rating values account for the highway, rail, marine and pipeline transport of hazardous substances plus the industrial and storage handling of these substances. The population hazard rating (HP) is given by: xii HP - HPtı + *"r m IND "^ "*sT where; HP = population rating associated with the highway transportation of hazardous materials, and the subletters H, R, m, IND and ST stand for highway, railway, marine, industry and storage respectively. Moreover, a maximum disaster potential for the assessment area was considered according to any accident which may occur a chemical spill and effects the population. Different disaster scenarios were made up for a few areas in Istanbul. Maximum disaster potential is given by ; DP = 0.5 * S * Dmax Where ; Dmax is the maximum population density in persons per km2 along a transportation route or adjacent to industry. S, is the area which must be evacuated immediately. The coefficient 0.5 assumes that one - half the people would be evacuated from the affected area before becoming disabled or expiring. The environmental hazard rating (HP) is given by: HE =: HISu ?+? HEp + HE-, t HEtmjj + HEcm + **E_ where ; HE = environmental rating associated with the highway transportation of hazardous materials, and the subletters H, R, m, IND, ST and p stand for highway, railway, marine, industry, storage and pipe lines respectively. Xlll In this study the necessary data were provided from T.C.K. (The Highway Administration of Turkish Republic), The Municipality of Istanbul, The Chemistry Laboratories of Erenköy and Halkali Customs, Harem Customs, The Health and Quarantine Administration of The Bosphorus, Istanbul Chamber of Maritime Commerce, The Harbor Administration of Istanbul, Istanbul Chamber of Industry. The results of the application of the model are given below; The population hazard index (HP) ; 2580*102 The environmental hazard index (HE) ; 4000*102 The maximum disaster potential (DP) ; 175* 102 If the results, given above, were compared with the examined area in the model, it would be seen that the values are much bigger. This shows the examined area exceeds the limit values according to the environmental hazard rating and involves in the class of cities which includes disaster potential. In consequence of the study, the propositions are given below ; 1. The method, used for calculating hazard index, could be used the classification of residential areas. 2. With this classification plans which reducing hazard degree or preventing them must be made for the residential areas involved in each class. 3. With the emergency plans (blue, green, red etc.) which would be used at any moment for a long term city plans relating to residential areas or city improve plans must be made. 4. On the examined area, because of the highly potential hazard risk on highway transport, hazardous substance transportation route must be dislocated into the distance as far as possible. 5. Hazard risk rating must be reduced by making new agreements or reviewing the international agreements on passing of The Bosphorus. 6. Industries that bring hazardous substances to residential areas are important point sources. For this reason they must be controlled with care. It is obvious that moving industries out of the residential areas may dislocate whether transportation of the hazardous substances or the usage into the areas which have much smaller amount xiv of population. This will obtain the hazard index and the disaster potential to be reduced on a large scale. This situation must be considered while the places of new industries which will be established are chosen. 7. No industry in any class (1 st, 2 nd, 3 rd. class non-sanitary (hygienic institution) must be allowed in the examined area. 8. Transportation of hazardous substance is not done by railway in the examined area at the present time. If a part of transportation of hazardous substance was moved to the railway, according to the results of model the value of highway population and environmental damage index would be reduced. 9. While the model is applied, some difficulties on collecting the data, needed for the Bhosphorus and its environment, were met. Collecting all kinds of statistical data, relating to the transportation of hazardous substance and the usage, by concerning foundations, evaluating and preparing to be used on the scientific studies, would make the model work healthier and practical. 10. There is a big chaos of concept and lack of knowledge about hazardous substances and their effects to environment and society. Carrying on scientific studies and completing legal arrangement immediately, play an important part in filling this gap.