Nels H. Mahle

The formation of chlorodibenzo-p-dioxins by air oxidation and chlorination of bituminous coal

Abstract A well characterized bituminous coal was subjected to high temperature air oxidation and chlorination. After an extensive cleanup procedure, the reaction products were analyzed for chlorinated dibenzo-p-dioxins by gas chromatography-mass spectrometry. Substantial quantities of chlorodibenzo-p-dioxins, some of which are known to be highly toxic, were observed with chlorination by hydrogen chloride and chlorine gas.

Perspectives of a large scale environmental survey for chlorinated dioxins: overview and soil data

Abstract On November 5, 1984, The Dow Chemical Company issued a report entitled: “Point Sources and Environmental Levels of 2378-TCDD on the Midland Plant Site of The Dow Chemical Company and in the City of Midland, Michigan.” This report is based upon the efforts of a 22-person task force who dedicated approx. 21 months of effort to the generation and analysis of over 6000 analytical data points regarding specific CDD/CDF concentrations in the four basic environmental elements of air, earth, fire (incineration), and water. A summarization of this study will be presented which includes methodology, analytical QA-QC criteria, and representative soil analyses, as they pertain to the survey conclusions.

Perspectives of a large scale environmental survey for chlorinated dioiins: water analyses

Abstract During 1983 and 1984, The Dow Chemical Company conducted a study to determine the extent of dioxin contamination at its Midland, Michigan plant and the surrounding area. The primary objectives of this study were to identify, rank order, and when possible quantify potential sources of dioxins to the environment and also to determine the extent of contamination in areas affected by the Dow facility. Early in the study, it was estimated that approximately 0.6g/year of 2378-TCDD was being emitted in 2.5 × 10 10 L of wastewater effluent. Data will describe observed sources of TCDD (both current and historical), environmental levels, existing water treatment methods, control measures taken, and future improvements on the water system to reduce TCDD in the effluent.