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A cohort study of intra-urban variations in volatile organic compounds and mortality, Toronto, Canada
2013
Villeneuve, Paul J. | Jerrett, Michael | Su, Jason | Burnett, Richard T. | Chen, Hong | Brook, Jeffrey | Wheeler, Amanda J. | Cakmak, Sabit | Goldberg, Mark S.
This study investigated associations between long-term exposure to ambient volatile organic compounds (VOCs) and mortality. 58,760 Toronto residents (≥35 years of age) were selected from tax filings and followed from 1982 to 2004. Death information was extracted using record linkage to national mortality data. Land-use regression surfaces for benzene, n-hexane, and total hydrocarbons were generated from sampling campaigns in 2002 and 2004 and assigned to residential addresses in 1982. Cox regression was used to estimate relationships between each VOC and non-accidental, cardiovascular, and cancer mortality. Positive associations were observed for each VOC. In multi-pollutant models the benzene and total hydrocarbon signals were strongest for cancer. The hazard ratio for cancer that corresponded to an increase in the interquartile range of benzene (0.13 μg/m3) was 1.06 (95% CI = 1.02–1.11). Our findings suggest ambient concentrations of VOCs were associated with cancer mortality, and that these exposures did not confound our previously reported associations between NO2 and cardiovascular mortality.
Afficher plus [+] Moins [-]Chlorinated pesticides in stream sediments from organic, integrated and conventional farms
2013
Shahpoury, Pourya | Hageman, Kimberly J. | Matthaei, Christoph D. | Magbanua, Francis S.
To determine if current sheep/beef farming practices affect pesticide residues in streams, current-use and legacy chlorinated pesticides were quantified in 100 sediment samples from 15 streams on the South Island of New Zealand. The study involved five blocks of three neighboring farms, with each block containing farms managed by organic, integrated and conventional farming practices. Significantly higher concentrations of dieldrin, ∑ endosulfans, ∑ current-use pesticides, and ∑ chlorinated pesticides were measured in sediments from conventional farms compared to organic and integrated farms. However, streams in the latter two farming categories were not pesticide-free and sometimes contained relatively high concentrations of legacy pesticides. Comparison of measured pesticide concentrations with sediment quality guidelines showed that, regardless of farming practice, mean pesticide concentrations were below the recommended toxicity thresholds. However, up to 23% of individual samples contained chlorpyrifos, endosulfan sulfate, ∑ DDT, dieldrin, or ∑ chlordane concentrations above these thresholds.
Afficher plus [+] Moins [-]Evaluating nutrient impacts in urban watersheds: Challenges and research opportunities
2013
Carey, Richard O. | Hochmuth, George J. | Martinez, Christopher J. | Boyer, Treavor H. | Dukes, Michael D. | Toor, Gurpal S. | Cisar, J. L. (John L.)
This literature review focuses on the prevalence of nitrogen and phosphorus in urban environments and the complex relationships between land use and water quality. Extensive research in urban watersheds has broadened our knowledge about point and non-point pollutant sources, but the fate of nutrients is not completely understood. For example, it is not known how long-term nutrient cycling processes in turfgrass landscapes influence nitrogen retention rates or the relative atmospheric contribution to urban nitrogen exports. The effect of prolonged reclaimed water irrigation is also unknown. Stable isotopes have been used to trace pollutants, but distinguishing sources (e.g., fertilizers, wastewater, etc.) can be difficult. Identifying pollutant sources may aid our understanding of harmful algal blooms because the extent of the relationship between urban nutrient sources and algal blooms is unclear. Further research on the delivery and fate of nutrients within urban watersheds is needed to address manageable water quality impacts.
Afficher plus [+] Moins [-]Cumulative impacts of human activities on urban garden soils: Origin and accumulation of metals
2013
Szolnoki, Zs | Farsang, A. | Puskás, I.
The concentration of heavy metals and soil properties in fifty urban garden soils of Szeged (SE Hungary) were determined to evaluate the cumulative impacts of urbanization and cultivation on these soils. Using two enrichment factors (EFs) (based on reference horizon; Ti as reference element) and multivariate statistical analysis (PCA), the origin of the studied elements was defined.According to statistical coincidence of EFs confirmed by t-test, anthropogenic enrichment of Cu (EF = 4), Zn (EF = 2.7) and Pb (EF = 2.5) was significant in topsoils. Moreover, PCA also revealed the geogenic origin of Ni, Co, Cr and As and differentiated two groups of the anthropogenic metals [Pb, Zn] [Cu]. Spatial distribution of the metals visualized by GIS reflected the traffic origin of Pb; while based on ANOVA, the anthropogenic source of Cu is relevant (mainly pesticides) and there is a statistically significant difference in its concentration depending on land use.
Afficher plus [+] Moins [-]Influence of land use on human bioaccessibility of metals in smelter-impacted soils
2013
Pelfrêne, Aurélie | Waterlot, Christophe | Douay, Francis
An investigation was undertaken to evaluate the empirical model developed by Pelfrêne et al. (2012), predicting the human bioaccessibility of Cd and Pb in smelter-contaminated agricultural topsoils, by including other soil uses: 50 urban and 65 woody habitat topsoils collected in the same area. The results showed that land use significantly affected the pseudototal metal concentrations and their oral bioaccessibility. However, whatever the soil's physicochemical parameters and degree of contamination, the ‘agricultural’ model can be used to simulate metal gastric bioaccessibility in urban and woody habitat soils. To simulate gastrointestinal bioaccessibility, this model can be used directly if the pseudototal metal concentrations are on the same order of magnitude as those usually recorded in the agricultural soils studied or after the use of a correction factor if these concentrations are greater. These results showed that the oral bioaccessibility predictions could be applicable for further environmental risk evaluation.
Afficher plus [+] Moins [-]An SPE LC–MS/MS method for the analysis of human and veterinary chemical markers within surface waters: An environmental forensics application
2013
Fenech, Cecilia | Nolan, Kieran | Rock, Luc | Morrissey, Anne
In this study, the use of co-occurring discriminators of sewage and manure was assessed as a potential way to disentangle sewage and manure sources. A suite of human and veterinary derived chemical markers, which includes pharmaceuticals and compound such as food additives, has been identified for this purpose. The suite was selected in such a manner as to provide additional source characterisation, e.g. differentiating raw versus treated sewage inputs. An SPE–LC–MS/MS method was developed and validated for the determined suite of chemical markers with a detection limit of up to 50 pg L−1. This represents one of the lowest limits of detection for pharmaceuticals reported in literature. To illustrate the suitability of the proposed method to differentiate sewage and manure inputs to surface water bodies, results from surface water samples collected at monitoring sites corresponding to specific land use types within Ireland are discussed.
Afficher plus [+] Moins [-]Integrated monitoring of particle associated transport of PAHs in contrasting catchments
2013
Schwientek, Marc | Rügner, Hermann | Beckingham, Barbara | Kuch, Bertram | Grathwohl, Peter
Water quality of rivers depends often on the degree of urbanization and the population density in the catchment. This study shows results of a monitoring campaign of total concentration of polycyclic aromatic hydrocarbons (PAHs) and suspended particles in water samples in adjacent catchments in Southern Germany with similar geology and climate but different degrees of urbanization. Defined linear relationships between total concentrations of PAHs in water and the amount of suspended solids were obtained indicating predominance of particle-facilitated transport. The slopes of these regressions correspond to the average contamination of suspended particles (Csus) and thus comprise a very robust measure of sediment pollution in a river. For the first time, we can show that Csus is distinct in the different catchments and correlates to the degree of urbanization represented by the number of inhabitants per total flux of suspended particles.
Afficher plus [+] Moins [-]Comparison of leaf saturation isothermal remanent magnetisation (SIRM) with anatomical, morphological and physiological tree leaf characteristics for assessing urban habitat quality
2013
Kardel, Fatemeh | Wuyts, Karen | Khavaninzhadeh, Ali Reza | Wuytack, Tatiana | Babanezhad, Manoochehr | Samson, Roeland
Leaf saturation isothermal remanent magnetisation (SIRM) is known as a good proxy of atmospheric, traffic related particulate matter (PM) concentration. In this study, we compared leaf SIRM with Leaf area (LA), leaf dry weight (LDW), specific leaf area (SLA), stomatal density (SD), relative chlorophyll content (RCC), chlorophyll fluorescence parameters (Fv/Fm and PI) for three urban tree types in the city of Ghent, Belgium. A negative significant relationship of LA, LDW and Fv/Fm, and a positive significant relationship of SLA with leaf SIRM was observed. Among all considered parameters, leaf SIRM had the highest potential for discrimination between contrasting land use classes. It was concluded that urban habitat quality can be monitored with leaf SIRM, independent of the other above mentioned plant parameters. The anatomical, morphological and physiological tree leaf characteristics considered are not good indicators for atmospheric PM, but might be interesting bio-indicators of other air pollutants than PM.
Afficher plus [+] Moins [-]Cadmium and associated metals in soils and sediments of wetlands across the Northern Plains, USA
2013
Jacob, Donna L. | Yellick, Alex H. | Kissoon, La Toya T. | Asgary, Aida | Wijeyaratne, Dimuthu N. | Saini-Eidukat, Bernhardt | Otte, Marinus L.
Cadmium, present locally in naturally high concentrations in the Northern Plains of the United States, is of concern because of its toxicity, carcinogenic properties, and potential for trophic transfer. Reports of natural concentrations in soils are dominated by dryland soils with agricultural land uses, but much less is known about cadmium in wetlands. Four wetland categories – prairie potholes, shallow lakes, riparian wetlands, and river sediments – were sampled comprising more than 300 wetlands across four states, the majority in North Dakota. Cd, Zn, P, and other elements were analyzed by ICP-MS, in addition to pH and organic matter (as loss-on-ignition). The overall cadmium content was similar to the general concentrations in the area's soils, but distinct patterns occurred within categories. Cd in wetland soils is associated with underlying geology and hydrology, but also strongly with concentrations of P and Zn, suggesting a link with agricultural land use surrounding the wetlands.
Afficher plus [+] Moins [-]Dispersion model evaluation of PM2.5, NOx and SO2 from point and major line sources in Nova Scotia, Canada using AERMOD Gaussian plume air dispersion model
2013
Gibson, Mark D. | Kundu, Soumita | Satish, Mysore
AERMOD was used to model the air dispersion of point and major line emissions of PM2.5 in Halifax and Pictou, NOX in Halifax and SO2 in Halifax, Sydney and Port Hawkesbury, Nova Scotia, Canada. Emission inventory data for 2004 were used in simulations within four, 50 km x 50 km, domains over annual, monthly and 1–hour averaging periods. Annual averaged surface concentration maps are reported. Modeled versus observed comparisons were made within each domain at the Government, National Air Pollution Surveillance (NAPS) monitoring sites (discrete receptors). Evaluation of the model was conducted on the annual, monthly and hourly results using a number of statistical methods that included R2, fractional bias, normalized mean square error and the fraction of predictions within a factor of two of the observations. The AERMOD model evaluation showed that there was good agreement between the modeled and observed SO2 concentration for the annual and monthly comparison but less skill at estimating the hourly comparisons for SO2 in Halifax and Sydney. AERMOD showed poor model skill at predicting SO2 in Port Hawkesbury over the same averaging periods. The model evaluation for PM2.5 in Halifax, PM2.5 in Pictou and NOX in Halifax showed poor agreements and model skill. The surface concentrations from the point and major lines sources in all domains from all metrics were found to be well below the National Air Quality Standards. AERMOD has shown its utility as a suitable model for conducting dispersion modeling from point and line sources in Nova Scotia with good model skill for estimating annual and monthly SO2 concentrations in Halifax and Sydney. The study highlights the validity of using emission inventory data to estimate the surface impact of major point and line sources within domains containing complex terrain, differing land use types and with large variability within the annual meteorology.
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