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.

The National Descriptive Model for Mercury in Fish (NDMMF) was applied to a Canada – wide dataset of fish mercury (Hg) concentrations to derive a common indicator of dietary methylmercury (MeHg) exposure (HgPREY) to piscivorous fish and wildlife. The NDMMF provided unbiased parameter estimates and strong spatial biases in prediction error were not apparent. Prediction error was comparatively higher when sample sizes were small and events with high Hg concentrations. Estimates of HgPREY from 1936 locations between 1990 and 2010 averaged 0.09 ± 0.07 μg g−1 (wet wt) and increased from west to east in a manner consistent with independent measures of MeHg exposure in piscivorous wildlife and conceptual models of aquatic ecosystem sensitivity to Hg methylation and bioaccumulation. The HgPREY dataset offers an approach to evaluate the risk of MeHg exposure to piscivorous fish and wildlife on a continental scale.

Environment Canada currently assesses dredged material proposed for disposal at sea using a two-tiered assessment framework. Tier 1 determines sediment geophysical properties and concentrations of four regulated chemical constituents (Cd, Hg, PAH and PCB), and “other chemicals of interest” based on lower action levels; this is followed by biological assessment. EC is pursuing a “data mining” approach to evaluate potential refinements by compiling sediment chemistry and toxicity datasets, and subjecting them to a series of decision protocols. This paper reports on database development and initial use, and recommends potential changes to Tier 1 chemical protocols and further work to address other aspects of the framework. Major findings include the poor performance of Hg and Cd as sentinels for other metals, the significance of the list of analytes (vs. the specific SQGs used) in decisions, and the potential for chemical upper action levels to save the expense of unnecessary toxicity testing.

High applications of P fertilizers and manure are general practice in intensive agriculture and may cause eutrophication in adjacent streams. Bioavailability of P can be estimated by sequential extractions commonly used for soil or sediment. A single combined method may facilitate more effective comparisons of topsoils and adjoining stream sediments, and enhance management decisions. In this study, the suitability of an established soil P sequential extraction was tested on stream bed sediments. The study was conducted in the Sumas River watershed in the agricultural Lower Fraser Valley, Canada. Sediment samples with differing land use (forest, low and high intensity agriculture) from 1993, 1994, 2008, and 2009 from 14 sites along the Sumas River and tributaries were used. Total sequential extraction concentrations were in agreement with aqua regia digestion (Rs = 0.96) and showed consistency over the study time sequence. P fractions released by 0.5 M NaHCO3 (median 14 %), 0.1 M NaOH (33 %), and 1.0 M HCl (38 %) were significantly (α = 0.05) higher than P released by other extractants. These three extraction steps provide a practical and time-effective assessment of P lability in stream sediments and may be used as a combined scheme for sediment and soil. Analytical results further revealed that land use has a major and characteristic impact on P lability. With a land use change from forest to intensive agriculture, results showed an increase in total P concentrations (30 to 4,000 ppm) and in P lability, in particular for the moderately labile NaOH-P fraction (20 to 50 %). © 2013 Springer Science+Business Media Dordrecht.

Phthalate acid esters (PAE), commonly named phthalates, are toxics classified as endocrine-disrupting compounds; they are primarily used as additives to improve the flexibility in polyvinyl chloride. Many studies have reported the occurrence of phthalates in different environmental matrices; however, none of these studies has yet established a complete overview for those compounds in the water cycle within an urban environment. This review summarizes PAE concentrations for all environmental media throughout the water cycle, from atmosphere to receiving waters. Once the occurrences of compounds have been evaluated for each environmental compartment (urban wastewater, wastewater treatment plants, atmosphere, and the natural environment), we reviewed data in order to identify the fate of PAE in the environment and establish whether geographical and historical trends exist. Indeed, geographical and historical trends appear between Europe and other countries such as USA/Canada and China, however they remain location dependent. This study aimed at identifying both the correlations existing between environmental compartments and the processes influencing the fate and transport of these contaminants into the environment. In Europe, the concentrations measured in waterways today represent the background level of contamination, which provides evidence of a past diffuse pollution. In contrast, an increasing trend has actually been observed for developing countries, especially for China.