A survey of drinking water supplies in the Province of Ontario for dioxins and furans

A survey of drinking water supplies in the Province of Ontario was initiated in 1983 to determine the extent of their contamination by polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). This drinking water survey arose from concerns regarding the discovery of PCDDs and PCDFs in sport fish from western Lake Ontario in the early 1980's.A total of 49 water supplies throughout all Regions of Ontario have been examined to date. Water supplies in the vicinity of chemical industries and pulp and paper mills were sampled more frequently; as many as 20 times. Detection limits were in the low parts per quadrillion (ppq) range for all tetra- to octachlorinated PCDDs and PCDFs.As of February 1989, 4, 347 results were received for 399 raw and treated water samples. Only 37 positive results were reported, constituting less than 1 percent of the total number of results. The O₈CDD congener accounted for 36 of the 37 positive results. The 2,3,7,8- TCDD isomer was not detected in any sample.     

Determination of mutagenic potential and organic contaminants of Great Lakes drinking water

Extracts of organic compounds were obtained, using XAD-2 macroreticular resin, from drinking water supplies in 12 Great Lakes municipalities. The extracts were tested for mutagenic potential using the Salmonella/mammalian-microsome assay and analysed for organochlorine pesticides, polyaromatic hydrocarbons, organophosphorous pesticides and trialkyl-arylphosphates. Grab samples of drinking water were also analysed for volatile organic compounds. Dose-related increases in mutagenicity were found in extracts from 11 of the drinking water supplies.     

Halogenated acetaldehydes: analysis, stability and fate in drinking water

In our previous studies, chloral hydrate has been the only chlorinated acetaldehyde determined in drinking water because authentic standards of other related haloacetaldehydes were not available. Recently, standards of dichloroacetaldehyde, bromochloroacetaldehyde, dibromoacetaldehyde, bromodichloroacetaldehyde, chlorodibromoacetaldehyde, and tribromoacetaldehyde have become available commercially. They were obtained and verified for purity and stability using a dual-column GC-ECD system. Each commercial standard was found to contain small amounts of the other target haloacetaldehydes (HAs). The stability of the HAs stock solutions was solvent dependent: in acetone, the brominated species partially degraded to bromoacetone, while all target HAs were stable in MTBE for up to 8 months. The analytical parameters, required for the quantification of HAs in water, were determined and used to evaluate the stability of the HAs in water. Under the conditions of the sampling protocol (field pH adjustment to pH 4.5 and storage at 4 degrees C), the target HAs were stable in water for up to 14 days. However, at typical drinking water pH and temperature conditions, the stability varied with the HA species, pH, temperature and storage period. The trihalogenated acetaldehydes degraded, in part, to their corresponding trihalomethanes (THMs) at increasing pH and temperature. Most target HAs were detected in drinking water samples collected from various Canadian drinking water systems, and the speciation was dependent on water parameters (e.g. bromide concentration) and treatment processes. From the water samples analysed, chloral hydrate ranged between 7% and 51% of the total HAs (w/w). The weigh ratio of total HAs to total THMs (10-46%) indicated that HAs contributed significantly to the pool of DBPs in drinking water.     

Chlorinated diphenyl ethers in human adipose tissue

Human adipose tissue samples were analysed for chlorinated diphenyl ethers using gas chromatography-mass spectrometry; none of these compounds were found at a detection limit of 20 ng/g.     

Polychlorinated dibenzodioxins and dibenzofurans in human adipose tissue samples from five Ontario municipalities

Human adipose tissue samples obtained during autopsies in 5 Canadian municipalities within the Great Lakes basin were analysed for polychlorinated dibenzodioxins and dibenzofurans using gas chromatography-high resolution-mass spectrometry. The mean congener values for male and female donors in each municipality are comparable with previously reported data. No significant differences in congener levels between male and female and between municipalities were detected. A positive correlation between congener level and age was observed for several congeners as well as for the total congener concentration expressed as its 2378-TCDD toxic equivalent.