[Show abstract][Hide abstract] ABSTRACT: Highway runoff is a significant source of contaminants entering many freshwater systems. To provide information on effects of highway runoff on aquatic biota, runoff samples were collected from three sites representing different classes of highways with low, intermediate and high traffic intensities. Samples were analysed for chloride, trace metals and polycyclic aromatic hydrocarbons (PAHs). Runoff from a major multilane divided highway, with the highest traffic intensity, contained the highest levels of chloride (45-19,135 mg/L) and metals. Runoff solids from this highway contained the highest levels of PAHs (19.7-2142 mg/kg). PAHs were also high (9.83-237 mg/kg and 26.4-778 mg/kg) at the intermediate and low traffic intensity sites, respectively. High concentrations of potent mutagens and carcinogens such as benzo(a) pyrene (0.414-124.62 mu g/g) and indeno-pyrene (0.549-50.597 mu g/g) were measured in the particulate phase of all runoff samples. Chloride concentrations of winter and early spring runoff were significantly higher (P < 0.001, t = 2.66) than during the rest of the year. Levels of contaminants depended on traffic intensity, road condition (age, composition, maintenance), the condition of metal structures (drains, guardrails, etc.) and seasonal conditions. A companion paper discusses spatial and temporal aspects of contaminant-associated toxicity of highway runoff.
Preview · Article · May 2011 · Water Quality Research Journal of Canada
[Show abstract][Hide abstract] ABSTRACT: The presence of pharmaceuticals and personal care products in the environment is a rapidly emerging international issue. A variety of drugs have been found in sewage effluents and surface waters in Europe, the United States, and Canada. This study examines the presence of selected pharmaceuticals (8 acidic drugs) and the antimicrobial substance, triclosan, in raw water and finished water of drinking water plants across southern Ontario. Twenty drinking water treatment plants that represented a variety of water sources and treatment process parameters were sampled. None of the raw or finished water samples taken from wells showed detectable levels of any of the acidic drugs or triclosan. River water samples downstream of sewage effluent outfalls showed the highest levels of contamination of the source water. Levels of naproxen and ibuprofen were elevated to levels as high as 176 and 150 ng/L, respectively, in raw water entering the treatment plants from a river source. Low levels of gemfibrozil (19.2 ng/L), diclofenac (15 ng/ L), indomethacin (6 ng/L), and the antimicrobial triclosan (34 ng/L) could be also detected in raw water from river sources. Raw water taken from large lakes also had very low but detectable levels of several acidic drugs, suggesting that these chemicals are widespread in the environment. Although treatment systems are not designed to remove these specific types of substances, most of the acidic drugs were not detectable in finished waters. Naproxen and triclosan were detectable in finished water but were significantly reduced in concentration relative to the raw water. The concentration of ibuprofen was detectable in the finished water of almost all treatment plants that used surface water as a source. This work demonstrates the potential of Ontario source waters, particularly river water sources, to contain trace levels of selected pharmaceuticals and personal care products. There is a need to complete a more comprehensive assessment of these compounds in source waters and of the factors influencing their treatment and removal from finished drinking water.
No preview · Article · Jan 2007 · Water Quality Research Journal of Canada
[Show abstract][Hide abstract] ABSTRACT: The distribution of female hormones, 17beta-estradiol and estrone, was determined in effluents of 18 selected municipal treatment plants across Canada. Replicate 24-h composite samples were collected from the influent and final effluent of each treatment plant, and the removal efficiency compared to the operational characteristics of the plants. In conventional activated sludge and lagoon treatment systems, the mean concentrations of 17beta-estradiol and estrone in influent were 15.6 ng/l (range 2.4-26 ng/l) and 49 ng/l (19-78 ng/l). In final effluents, the mean concentrations of both 17beta-estradiol and estrone were reduced to 1.8 ng/l (0.2-14.7 ng/l) and 17 ng/l (1-96 ng/l), respectively. 17beta-estradiol was removed effectively, >75% and as high as 98%, in most of the conventional mechanical treatment systems with secondary treatment. The removal of estrone was much more complex with removal varying from 98% to situations where the concentrations in the effluent were elevated above that detected in the influent. The estrogenicity, measured using a transfected estrogen receptor in yeast (YES) assay, was also variable, ranging from high removal to elevations of estrogenicity in final effluent. Although the apparent removals were not statistically correlated with either hydraulic (HRT) or solid (SRT) retention times, plants or lagoons with high SRT were very effective at reducing the levels of hormones. Well-operated plants that achieved nitrification also tended to have higher removal of hormones than those that did not nitrify. Laboratory aerobic reactor experiments confirmed the rapid removal of 17beta-estradiol, estrone, and estrogenicity when exposed to sewage slurries.
Full-text · Article · Jan 2005 · Science of The Total Environment
[Show abstract][Hide abstract] ABSTRACT: Safe potable water is a luxury that is generally unavailable to the majority of rural and suburban populations of developing, underdeveloped, and often developed countries. Important consid- erations in the development and maintenance of safe water supplies is the availability and use of efficient, inexpensive, and appropriate technology for removing microbial hazards, parasites, and toxicants. The Manz intermittent slow sand filter was known to be user friendly, small enough to fit into the smallest kitchen, and could remove up to 97% of the fecal coliforms present in the raw water before treatment by the Manz filter. This filter was evaluated for its ability to remove parasitic cysts and toxicants as well as bacteria. Using two different filters and two different water supplies our results indicated that the intermittent slow sand filter could remove 83+% total heterotrophic bacterial populations, 100% of Giardia cysts, 99.98% of Cryptosporidium oocysts, and 50 -90% of organic and inorganic toxicants when administered in concentrations varying from 10 - )100 = environmental pollution levels. Methodology details are provided in the paper. Q 1999 by John Wiley & Sons, Inc. Environ Toxicol 14: 217)225, 1999
Preview · Article · May 1999 · Environmental Toxicology
[Show abstract][Hide abstract] ABSTRACT: A former mercury plant, where mercury salts and organomercurials for pesticide use were produced, caused soil contamination in high concentrations. Typical organomercurial products included ethylmercury, phenylmercury, methoxyethylmercury and ethoxyethylmercury compounds. Risk assessment of these sites must be carried out before any major clean-up processes can be planned. A sensitive speciation technique for the various organomercury species in environmental matrices is a prerequisite for toxicity investigations. In this connection, a high-performance liquid chromatography-atomic fluorescence spectrometry (HPLC-AFS) technique has been developed to differentiate between and determine the presence of eight organomercury compounds in environmental samples. Using this technique, methylmercury, ethylmercury and phenylmercury and some unknown organomercury species were found in soil samples collected from the sites of an old mercury products producing plant. With regard to risk assessment, it is necessary to assess the toxicity of the organomercurials. As different microbial metabolic pathways react differently to mercury and its compounds, batteries of bioassays are, therefore, useful to evaluate the toxicity of pollutants. To describe the toxicity and genotoxicity of MeHg+, MeOEtHg+, EtHg+, EtOEtHg+ and PhHg+, p-tolymercury chloride, nitromersol and Hg2+ six bioassays were used: resazurin reduction method, Spirillum volutans test, nematode toxicity assay Panagrellus redivivus, Toxi-Chromotest and SOS-Chromotest. A ranking of the toxicity of the organomercurial is shown. The SOS-Chromotest indicated genotoxicity for 5-7 organomercurials.
[Show abstract][Hide abstract] ABSTRACT: Over the past eight years we have been evaluating a variety of sediment extraction procedures and have finally settled for a three phase sequential procedure which involves pore water extraction followed by Milli‐Q water extraction. Then the dewatered sediment is extracted by a solution containing 10% methanol, 10% DMSO and 80% Milli‐Q water. This three phase sequential extraction procedure was applied to Hamilton Harbour sediments and the extracts were tested for toxicant activity by the battery of tests approach. Based on these samples, it would appear that pore water bioassay results are probably most indicative of the bioavailable toxicants load in Hamilton Harbour sediments.
Full-text · Article · Sep 1994 · Journal of environmental science and health. Part A, Environmental science and engineering & toxic and hazardous substance control
[Show abstract][Hide abstract] ABSTRACT: In trying to establish the extent and degree of impact of point and nonpoint source contaminants on riverine systems, it is important to know the implications of the data obtained from various sampling points in a riverine system. Spatial variability between water and/or sediment samples collected in close approximation at the same sites was assessed by the battery of tests approach. In these samples there appeared to be no consistent relationship between sediment structure, microbial population, and toxicant concentrations. Furthermore the ATP-TOX System and Mutatox tests were the most responsive tests in all types of samples. Since sediments with their bound contaminants may be an important factor in this data interpretation, different methods for releasing and concentrating the sediment bound contaminants were evaluated. The results and implications of these results are described.
No preview · Article · Aug 1991 · Environmental Toxicology and Water Quality
[Show abstract][Hide abstract] ABSTRACT: In this study, a new approach has been taken to evaluate Saint John River water and sediment conditions. A battery of biochemical, microbiological and bioassay tests were used to identify degraded or degrading sediments and waters. Data were obtained from waters and sediments at 38 sites within the Saint John River Basin. The data suggested that the following four sites had the highest priority concern: Little River No. 34, Grand Bay, Saint John River near Boars Head No. 33, Madawaska River below mill No. 7 and St Francois-de-Madawaska, mill stream No. 2. The data also indicated that microbial population, biochemical or bioassay tests performed independently do not provide realistic evaluations of priority concern areas and that the “battery of tests” approach is necessary to provide additional information.