This thesis deals with the issue of fires of municipal and industrial wastes, particularly of rubber and halogenated polymers. When these materials burn, significant amount of harmful substances liberate into environmental compartments. Analysis of samples subjected to thermal decomposition in laboratory conditions explored formation of characteristic compounds in dependence on conditions of combustion. Samples of air, water and soil taken from real fires that occurred between the years 2007 – 2011 in the region of Western Bohemia monitored spreading of these substances into the environment. Majority of these samples were analysed by the means of gas chromatography with mass spectrometric detection. Additionally the effect of extinguishing methods and use of fire extinguishers on formation and spreading of combustion products was studied, especially in soil and in water sources.

Although products of coal combustion (PCCs) such as coal ash are currently exempted from classification as a hazardous waste in the United States under the 1976 Resource Conservation and Recovery Act (RCRA), the U.S. Environmental Protection Agency (EPA) is now revising a proposed rule to modify disposal practices for these materials in order to prevent contamination of ground- and surface water sources by leached trace elements. This paper analyzes several aspects of EPA’s scientific reasoning for instating the rule, with the intent of answering the following questions: 1) Are EPA’s cited values for PCC production and disposal accurate estimates of annual totals?; 2) In what ways can EPA’s leaching risk modeling assessment be improved?; 3) What is the total quantity of trace elements contained within all PCCs disposed annually?; and 4) What would be the potential costs and feasibility of reclassifying PCCs not under RCRA, but under existing NRC regulations as low-level radioactive waste (LLRW)? Among the results of my calculations, I found that although EPA estimates for annual PCC disposal are 20% larger than industry statistics, these latter values appear to be closer to reality. Second, EPA appears to have significantly underestimated historical PCC disposal: my projections indicate that EPA’s maximum estimate for the quantity of fly ash landfilled within the past 90 years was likely met by production in the last 30 years alone, if not less. Finally, my analysis indicates that while PCCs may potentially meet the criteria for reclassification as low-level radioactive waste by NRC, the cost of such regulation would be many times that of the EPA June proposed disposal rule ($220-302 billion for PCCs disposed in 2008 alone, versus $1.47 billion per year for the Subtitle C option and $236-587 million for Subtitle D regulatory options). / text

Contexte : L’exposition professionnelle aux sous-produits de combustion est répandue et peut contribuer à l'étiologie du cancer du sein. Cette étude vise à estimer l’association entre l’exposition professionnelle à certains sous-produits de combustion et le risque postménopausique de cancer du sein. Méthodes : Cette étude cas-témoins populationnelle comprenait des femmes ménopausées âgées de 47-75 ans résidant à Montréal, Québec (2008-2011). Les cas incluaient 695 femmes ayant reçu un diagnostic cancer du sein malin et 608 témoins sélectionnés aléatoirement à partir de la Liste électorale du Québec, appariés aux cas en fréquence (groupes d'âge de 5 ans). L’information sur les facteurs de risque et l'historique professionnel a été recueillie par entrevue. Des hygiénistes industriels ont évalué l'exposition à 293 agents, dont six sous-produits de combustion. Le risque de cancer du sein associé à l'exposition professionnelle à certains sous-produits a été estimé, pour l'ensemble des tumeurs et leurs sous-types moléculaires, par régression logistique inconditionnelle avec rapports de cotes ajustés (RC) et intervalles de confiance à 95 % (IC 95%). Résultats : Des associations positives suggestives ont été trouvées entre l'exposition aux hydrocarbures aromatiques polycycliques et certains sous-types moléculaires de tumeurs : toutes tumeurs, RC=1,18 (IC95%=0,80-1,76), tumeurs luminales A, RC=1,25 (IC95%=0,81-1,93) et tumeurs luminales B, RC=2,09 (IC95%=0,87-4,60). Un risque élevé a été observé avec l'exposition aux fumées de cuisson pour les tumeurs HER2-enrichies (RC=2,63, IC95%=0,98-6,40). Conclusion : L'exposition à certains sous-produits de combustion peut augmenter le risque de certains sous-types moléculaires de cancer du sein. Des études futures explorant cette association sont justifiées. / Background: Postmenopausal breast cancer is the most common cancer among women, yet little is known about its association with occupational exposures. Exposure to combustion by-products is widespread in occupational settings and may contribute to breast cancer etiology. Here, we sought to estimate the association between lifetime occupational exposure to select combustion by-products and the risk of postmenopausal breast cancer. Methods: This population-based case-control study included postmenopausal women residing in Montreal, Quebec (2008-2011). Cases comprised 695 women aged 47-75 years diagnosed with incident malignant breast cancer, and 608 controls randomly selected from the Quebec Electoral List, frequency-matched to cases (5-year age groups). Information on risk factors and employment history was collected by interview. Exposure to 293 agents, including six combustion by-products was assessed by industrial hygienists. Unconditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for breast cancer risk, both overall and by tumor molecular subtypes, to occupational exposure to select combustion by-products. Results: We found suggestive positive associations between exposure to polycyclic aromatic hydrocarbons and certain molecular subtypes of tumors: for all tumors, OR=1.18 (95% CI: 0.80-1.76), Luminal A tumors, OR=1.25 (95% CI: 0.81-1.93) and Luminal B tumors, OR=2.09 (95% CI: 0.87-4.60). Elevated risked were observed for exposure to cooking fumes for HER2-enriched tumors (OR=2.63, 95% CI: 0.98-6.40). Conclusion: Exposure to select combustion by-products may increase the risk of certain hormonal subtypes of breast cancer. Future studies exploring this association are warranted.