Observations and Interpretations from the Canadian Fine Particle Monitoring Program

ABSTRACT

Canadian particle monitoring programs examining PM10, PM2.5, and particle composition have been in operation for over 10 years. Until recently, the measurements were manual/filter-based with 24-hr sample collection varying in frequency from daily to every sixth day, using GrasebyAnderson dichotomous samplers. In the past few years, these monitoring activities have been expanded to include hourly measurements using tapered element oscillating microbalances (TEOMs). This continuous monitoring program started operation focusing on PM_10, but now emphasizes PM_2.5 through the addition of more TEOMs and switching of the inlets of some of the existing units. The data from all of these measurement activities show that there are broad geographical differences and also local- to regional-scale spatial differences in mass and composition of PM2.5. Due to variations in sources, significantly different PM2.5 concentrations are not uncommon within the same city. Comparison of nearby urban and rural sites indicates that 30 and 40% of the PM_2.5 is from local urban sources in Montreal and Toronto, respectively. Hourly PM_2.5 measurements in Toronto suggest that vehicular emissions are an important contributor to urban PM_2.5. There has been a decreasing trend in urban PM_2.5, with annual average concentrations between the 1987–1990 and 1993–1995 periods decreasing by 11 to 39%, depending upon the site. The largest declines were in Montreal and Halifax, and the smallest decline was in Toronto. Comparison of 24-hr TEOM and manual dichotomous sampler PM_2.5 measurements from a site in Toronto indicates that the TEOM results in lower concentrations. The magnitude of this difference is relatively small in the warmer months, averaging about 12%. During the colder months the difference averages about 23%, but can be as large as 50%.     

Improvement of Air Quality in a Small Indoor Ice Arena by Effective Emission Control in Ice Resurfacers

ABSTRACT

The effectiveness of a new emission control system in the ice resurfacer was tested in an exhaust gas emission laboratory, and the improvement of the air quality in a small, enclosed ice arena was demonstrated in a 4.5-month follow-up study. The emission control system consisted of a lambda sensor-controlled fuel supply and a three-way metallic catalyst that were applied to a propane-fueled resurfacer. In the laboratory tests, the engine emissions of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NO ) reduced simultaneously by 91, 90, and 96%, respectively. During the air quality follow-up the median 1-hour average nitrogen dioxide (N0₂) concentration inside the ice arena decreased from 430 ug/m³ (230ppb) to 58 ug/m³ (31 ppb), and that of CO decreased from 4.4 mg/m³ (3.8 ppm) to 1.5 mg/m³ (1.3 ppm). The new emission control system proved to be a feasible, reliable, and effective means to improve the indoor air quality in the ice arena. However, continuous mechanical ventilation was necessary during all business hours in order to achieve and maintain a fully acceptable air quality with this technology.     

Aerosol Particle Number Concentration Measurements in Five European Cities Using TSI-3022 Condensation Particle Counter over a Three-Year Period during Health Effects of Air Pollution on Susceptible Subpopulations

Abstract

In this study, long-term aerosol particle total number concentration measurements in five metropolitan areas across Europe are presented. The measurements have been carried out in Augsburg, Barcelona, Helsinki, Rome, and Stockholm using the same instrument, a condensation particle counter (TSI model 3022). The results show that in all of the studied cities, the winter concentrations are higher than the summer concentrations. In Helsinki and in Stockholm, winter concentrations are higher by a factor of two and in Augsburg almost by a factor of three compared with summer months. The winter maximum of the monthly average concentrations in these cities is between 10,000 cm^-3 and 20,000 cm^-3, whereas the summer min is ?;5000–6000 cm^-3. In Rome and in Barcelona, the winters are more polluted compared with summers by as much as a factor of 4–10. The winter maximum in both Rome and Barcelona is close to 100,000 cm^-3, whereas the summer minimum is >10,000 cm^-3. During the weekdays the maximum of the hourly average concentrations in all of the cities is detected during the morning hours between 7 and 10 a.m. The evening maxima were present in Barcelona, Rome, and Augsburg, but these were not as pronounced as the morning ones. The daily maxima in Helsinki and Stockholm are close or even lower than the daily minima in the more polluted cities. The concentrations between these two groups of cities are different with a factor of about five during the whole day. The study pointed out the influence of the selection of the measurement site and the configuration of the sampling line on the observed concentrations.     

Thyroid ultrasound volume, structure and function after long-term high exposure of large population to polychlorinated biphenyls, pesticides and dioxin

We examined 2,046 adults (834 males and 1,212 females aged 20-75 years) from polluted district in East Slovakia (POLL) and two neighboring upstream and upwind located districts of background pollution (BCGR). By ultrasound we estimated the thyroid volume (ThV), hypoechogenicity (HYE), nodules and cysts. Serum levels of thyrotropin (TSH), thyroperoxidase antibodies (TPOab) and thyroglobulin were estimated by electrochemiluminiscent assay and these of 15 PCB congeners, p,p'-DDE, p,p'-DDT, hexachlorobenzene (HCB) and hexachlorocyclohexane by high-resolution gas chromatography. In 320 subjects also selected hydroxylated and methylsulfonated PCB metabolites, polychlorinated dibenzo-dioxins (PCDDs), -furans (PCDFs), five dioxin-like coplanar and eight mono-ortho PCB congeners were estimated. Urinary iodine was measured by automatic microplate method. Reciprocal positive association was found between three major POPs (PCBs, DDE and HCB), the levels of these and also PCDDs plus PCDFs in polluted area being considerably higher than in background pollution area. ThV in groups of males and females from POLL with high PCBs level was significantly higher (p<0.001 by t-test) then in age and sex matched groups from BCGR with low PCBs level. In 1,048 males and females aged <60 years with serum PCBs level >1,000 ng g(-1) lipid (median=1,756 ng g(-1)) a significant effect of age on ThV was found (p<0.01 by ANOVA), while in 921 respective subjects with PCBs level <1,000 ng g(-1) (median=661 ng g(-1)) it was not. These findings supported the view on the additional effect of PCBs on ThV other than that of age. Since the urinary iodine in both districts showed optimal range, any interfering effect of unsatisfactory iodine intake on ThV may be excluded. The frequency of autoimmune thyroiditis signs such as HYE, increased serum level of TPOab and TSH resulting in subclinical or overt thyroid hypofunction was positively associated with sex, age and organochlorine levels. The increase of such frequency in males with POPs levels was much more abrupt than that in females. No considerable differences in the frequency of thyroid nodules as related to PCBs level were found.     

Tissue heavy metal concentrations of stranded California sea lions (Zalophus californianus) in Southern California

Concentrations of nine heavy metals (As, Cd, Cu, Fe, Hg, Pb, Mn, Mo and Zn) were determined in the hepatic and renal tissues of 80 stranded California sea lions (Zalophus californianus). Significant age-dependant increases were observed in liver and kidney concentrations of cadmium and mercury, and renal zinc concentrations. Hepatic iron concentrations were significantly higher in females than males. Animals with suspected domoic acid associated pathological findings had significantly higher concentrations of liver and kidney cadmium; and significantly higher liver mercury concentrations when compared to animals classified with infectious disease or traumatic mortality. Significantly higher hepatic burdens of molybdenum and zinc were found in animals that died from infectious diseases. This is the largest study of tissue heavy metal concentrations in California sea lions to date. These data demonstrate how passive monitoring of stranded animals can provide insight into environmental impacts on marine mammals.     

Panel Discussion on Energy Efficiency

The session on energy efficiency had no formal presentations and was organized as a panel discussion with four panelists. It was concluded that energy efficiency and saving measures on the short term is the most effective way to contribute to a sustainable energy system. Measures to improve and encourage energy efficiency should be implemented at all levels; municipal/local, national and super-national. Prices can be an effective instrument but need to be combined with systemic level measures. The transport sector was identified as the one with largest near future potential for increased energy efficiency. Agriculture and food is also an area with very large energy consumption and large potential for increased energy efficiency. The global population issue is yet another relevant, challenging and complex issue. It was noted that energy audits for end users in business and society increase awareness and insights into what they pay for, and they are likely to promote actions to save energy. Many measures are believed to suffer from Jevin’s paradox, i.e., that more efficient use of energy just leads to more energy consumption somewhere else. Many examples were given, however, where this does not happen. Another point put forward was that measures to make the energy system more efficient do not only mean constraints and regulations but also create great opportunities for market actors and societies.     

Contrasting Lumped and Distributed Hydrology Models for Estimating Climate Change Impacts on California Watersheds1

Maurer, Edwin P., Levi D. Brekke, and Tom Pruitt, 2010. Contrasting Lumped and Distributed Hydrology Models for Estimating Climate Change Impacts on California Watersheds. Journal of the American Water Resources Association (JAWRA) 46(5):1024–1035. DOI: 10.1111/j.1752-1688.2010.00473.x Abstract: We compare the projected changes to streamflows for three Sierra Nevada rivers using statistically downscaled output from 22 global climate projections. The downscaled meteorological data are used to drive two hydrology models: the Sacramento Soil Moisture Accounting model and the variable infiltration capacity model. These two models differ in their spatial resolution, computational time step, and degree and objective of calibration, thus producing significantly different simulations of current and future streamflow. However, the projected percentage changes in monthly streamflows through mid-21st Century generally did not differ, with the exceptions of streamflow during low flow months, and extreme low flows. These findings suggest that for physically based hydrology models applied to snow-dominated basins in Mediterranean climate regimes like the Sierra Nevada, California, model formulation, resolution, and calibration are secondary factors for estimating projected changes in extreme flows (seasonal or daily). For low flows, hydrology model selection and calibration can be significant factors in assessing impacts of projected climate change.     

Use of fungal technology in soil remediation: A Case Study

Two white rot fungi Irpex lacteus and Pleurotus ostreatus and a PAH-degrading bacterial strain of Pseudomonas putida were used as inoculum for bioremediation of petroleum hydrocarbon-contaminated soil from a manufactured-gas-plant-area. Also two cocultures comprising a fungus with Pseudomonas putida were applied. After 10-week treatment out of 12 different PAHs, concentration of phenanthrene, anthracene, fluoranthene and pyrene decreased up to 66%. The ecotoxicity of the soil after bioremediation did not reveal any effect on the survival of Daphnia magna, a crustacian. However, the toxic effect on seed germination of plant Brassica alba and oxidoreductase activity of bacterium Bacillus cereus decreased after 5 and 10 weeks of treatment.