Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 21
Filter
1.
Can J Public Health ; 114(2): 218-228, 2023 04.
Article in English | MEDLINE | ID: mdl-36787032

ABSTRACT

SETTING: On March 17, 2020, a state of public health emergency was declared in Alberta under the Public Health Act in response to the COVID-19 pandemic. Congregate and communal living sites were environments with a high risk of exposure to and transmission of COVID-19. Consequently, provincial efforts to prevent and manage COVID-19 were required and prioritized. INTERVENTION: During the first 9 months of the pandemic, vaccines were unavailable and alternate strategies were used to prevent and manage COVID-19 (e.g., physical distancing, masking, symptom screening, testing, isolating cases). Alberta Health Services worked with local, provincial, and First Nations and Inuit Health Branch stakeholders to deliver interventions to support congregate and communal living sites. Interventions included resources and site visits to support prevention and preparedness, and the creation of a coordinated response line to serve as a single point of contact to access information and services in the event of an outbreak (e.g., guidance, testing, personal protective equipment, reporting). OUTCOMES: Data from an internal monitoring dashboard informed intervention uptake and use. Online survey results found high levels of awareness, acceptability, appropriateness, and use of the interventions among congregate and communal living site administrators (n = 550). Recommendations were developed from reported experiences, challenges, and facilitators, and processes were improved. IMPLICATIONS: Provincially coordinated prevention, preparedness, and outbreak management interventions supported congregate and communal living sites. Efforts to further develop adaptive system-level approaches for prevention and preparedness, in addition to communication and information sharing in complex rapidly changing contexts, could benefit future public health emergencies.


RéSUMé: LIEU: Le 17 mars 2020, un état d'urgence sanitaire a été déclaré en Alberta en vertu de la Loi sur la santé publique pour riposter à la pandémie de COVID-19. Les habitations collectives étaient des environnements qui présentaient un risque élevé d'exposition à la COVID-19 et de transmission du virus. Des efforts provinciaux pour prévenir et gérer la COVID-19 ont donc été nécessaires et se sont vu accorder la priorité. INTERVENTION: Comme des vaccins n'étaient pas disponibles au cours des neuf premiers mois de la pandémie, d'autres stratégies ont été utilisées pour prévenir et gérer la COVID-19 (p. ex. distanciation physique, port du masque, dépistage des symptômes, tests, isolation des cas). Les Services de santé de l'Alberta ont travaillé avec les acteurs locaux et provinciaux et les fonctionnaires de la Direction générale de la santé des Premières nations et des Inuits pour mener des interventions à l'appui des habitations collectives. Ces interventions ont compris des ressources et des visites sur place pour appuyer la prévention et la préparation, et la création d'une ligne d'intervention coordonnée qui a servi de guichet unique d'accès à l'information et aux services en cas d'éclosion (p. ex. conseils, tests, équipement de protection individuelle, déclaration des cas). RéSULTATS: Les données d'un tableau de bord interne ont permis d'en savoir plus sur la popularité et l'utilisation de ces interventions. Les résultats d'un sondage en ligne ont fait état de niveaux élevés de connaissance, d'acceptabilité, de pertinence et d'utilisation des interventions chez les administrateurs d'habitations collectives (n = 550). Des recommandations ont été élaborées à partir des expériences signalées et des éléments positifs et négatifs, et les processus ont été améliorés. CONSéQUENCES: Des interventions de prévention, de préparation et de gestion des éclosions coordonnées à l'échelle provinciale ont soutenu les habitations collectives. Il pourrait être utile pour les futures urgences sanitaires de développer ces approches d'adaptation systémiques pour la prévention et la préparation, en plus des communications et de l'échange d'informations dans des contextes en évolution rapide.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , COVID-19/prevention & control , Public Health , Pandemics/prevention & control , Alberta/epidemiology , Disease Outbreaks/prevention & control , Health Services
2.
Cureus ; 14(8): e27726, 2022 Aug.
Article in English | MEDLINE | ID: mdl-36106233

ABSTRACT

Introduction The use of all-terrain vehicles (ATVs) has become increasingly popular as an outdoor recreational activity among people living in the United States, particularly in areas such as the southeast. There are significant risks involved with riding ATVs, especially in the pediatric population, due to lack of training and experience. The purpose of this study was to evaluate the outcomes of pediatric patients involved in ATV-associated accidents. Methods This study is a retrospective review of 98 pediatric patients ages 15 years and younger involved in ATV accidents who were admitted to a pediatric hospital between January 2015 and December 2020. Outcomes, including types of injuries sustained, length of hospital stay, length of ICU stay, and injury severity score (ISS) were analyzed between age groups (0-5, 6-10, and 11-15). Results The mean hospital stay across all age groups was 1.7 ± 1.9 days, mean ICU stay was 3.8 ± 4.0 days, and mean injury severity score (ISS) was 5.9 ±4.8. The 11-15-year-old age group had a significantly longer hospital stay and higher ISS scores compared to both of the younger age groups (0-5 and 6-10 years old). There was no difference in ICU days between the age groups. Orthopedic injuries were the most common type of injury, occurring in 55% of all patients, followed by head injuries in 29% of patients, and spinal fractures in 2% of patients. The most common orthopedic fracture in the 11-15-year-old group was tibia/fibula, while humerus fractures were the most common type of fracture in the 0-5 and 6-10 year age groups. Orthopedic procedures were required in 35% of all included patients. There was no statistically significant difference in types of injuries and types of fractures sustained between each group. Chest injuries, including pneumothorax, lung contusions, and rib fractures, occurred most often in the older age group 11-15 years (n=65). Those who experienced chest injuries had a higher ISS, although it was not statistically significant (p=0.06) compared to those who did not have chest injuries. There was no difference in hospital or ICU length of stay in patients with chest injuries. Conclusions The results of this study demonstrate the outcomes of pediatric patients admitted for ATV accidents at a rural Appalachian pediatric hospital and provide an overview of the most common injuries involved in this trauma mechanism. Pediatric patients aged 11-15 years of age involved in ATV accidents are at risk for longer hospital length of stay and higher ISS compared to younger age groups. Additionally, patients ages 11-15 were more susceptible to chest injuries following ATV accidents. The results of this study will be used to develop a standardized trauma protocol for the management of this specific trauma mechanism in the pediatric population based on common injury patterns among each age group.

3.
Appl Plant Sci ; 10(4): e11487, 2022.
Article in English | MEDLINE | ID: mdl-36034189

ABSTRACT

Premise: Aquatic macrophyte species abundance and nutrient affinity are used in metrics to assess the trophic condition of lakes and rivers. The development of these indices is often regional, with inter-regional comparisons being complicated by the lack of taxonomic overlap. Here, we use a traits-based approach to expand the geographic scope of existing metrics. Methods: We generalized European trophic affinity values using the response of plant growth form to the light-nutrient gradient, then applied these values to sites in Canada. We evaluated the method's performance against the measured total phosphorus concentration (TP). Results: Free-floating and emergent growth forms were associated with enriched waters (>0.2 mg/L TP), whereas rosette forms were associated with oligotrophic conditions (<0.05 mg/L TP). The responses were longitudinally consistent, and the site scores among indices were highly collinear. Growth form-based scores were more strongly correlated with TP than were species-based scores (0.42-0.56 versus 0.008-0.25). Discussion: We leveraged the ecological relationship between increased surface water nutrient enrichment and the dominance of particular aquatic plant growth forms to generalize aquatic plant trophic indices. We demonstrated an approach for adapting species-based indices to plant traits to facilitate a broader geographic application and simpler data collection, which could be used to develop an easily applied trait-based method of assessing water nutrient status.

5.
Water Res ; 185: 116139, 2020 Oct 15.
Article in English | MEDLINE | ID: mdl-32823192

ABSTRACT

Phosphorus (P) is an essential macronutrient for algal communities, but in excess can exacerbate stream eutrophication. However, P loadings to streams vary temporally from continuous to episodic as a result of inputs from point and non-point sources, respectively. P loading pattern can thus alter the temporal availability of P and may influence effects of P enrichment on algal communities. We assessed how P loading pattern influences algal biomass and composition by conducting a 29-day P enrichment experiment in nine artificial streams exposed to either: (1) continuous P enrichment; (2) episodic P enrichment, or; (3) no P enrichment. P enrichment increased algal biomass accrual, but peak biomass did not differ between continuously and episodically enriched treatments. Maximum absolute growth rates were also comparable between P enriched treatments. However, episodic P additions sustained elevated rates of biomass accrual, whereas absolute growth rates in the continuously enriched communities declined towards the end of the experiment. P enrichment resulted in comparable increases in relative abundance of chlorophytes and decreased proportions of bacillariophytes and charophytes in algal communities for continuously and episodically enriched treatments. However, composition of bacillariophyte (diatom) assemblages differed significantly among all P enrichment treatments in accordance with species autecological attributes for P. Our results demonstrate that episodic and continuous P enrichment may augment algal biomass similarly. Yet, P loading pattern regulated the composition of algal communities. Thus, remedial management strategies for the control of nuisance algae production may require focus on the predominant source of P to streams. Finally, species specific responses of diatom assemblages to P enrichment and associated loading patterns suggests this taxonomic group may have potential as diagnostic indicators for identifying the presence of key nutrient sources associated with eutrophication of stream ecosystems.


Subject(s)
Phosphorus , Rivers , Biomass , Ecosystem , Eutrophication
7.
Environ Sci Technol ; 53(21): 12856-12864, 2019 Nov 05.
Article in English | MEDLINE | ID: mdl-31621313

ABSTRACT

Bitumen mining and upgrading in northeastern Alberta, Canada, releases toxic pollutants into the atmosphere, including mercury (Hg) and methylmercury (MeHg). This Hg and MeHg is then deposited to the surrounding landscape; however, the fate of these contaminants remains unknown. Here, we compare snowpack chemistry to high-frequency measurements of river water quality across six watersheds (five impacted by oil sands development and one unimpacted). Catchment scale snowpack Hg and MeHg loads normalized to watershed area were highest near oil sands operations. River water Hg concentrations and loads tracked discharge and tended to be higher downstream of mining operations, while MeHg concentrations and loads increased through the summer, reflecting peak summer MeHg production rates. Except in the reference watershed, snowpack Hg and MeHg loads equaled or exceeded the amount of Hg and MeHg exported during freshet and, in some cases, the entire hydrologic year. This suggests landscapes across the oil sands region, which are dominated by low-relief wetlands and other shallow-water systems, are accumulating Hg and MeHg. Importantly, during years of high discharge, these low-relief systems appear to become better connected and flush MeHg (and Hg) from the watershed. Thus, these watersheds may act as temporary, rather than as permanent, natural repositories of oil sands contaminants.


Subject(s)
Mercury , Methylmercury Compounds , Water Pollutants, Chemical , Alberta , Environmental Monitoring , Oil and Gas Fields
8.
Sci Total Environ ; 626: 1382-1393, 2018 Jun 01.
Article in English | MEDLINE | ID: mdl-29898545

ABSTRACT

Bitumen-bearing suspended sediment (SS) eroded from the McMurray Formation (MF) are fine grained (silts and clays) and coated with natural hydrophobic oils. This results in poor settling and long range transport of associated contaminants. There was a longitudinal increase in polycyclic aromatic compound (PAC) concentrations for rivers that erode the MF from upstream to downstream regardless of time-of-year, while loads were substantially increased during high flow periods when the erosive forces are the greatest and the overland flow contribution is high. Within the MF, variation in PAC contributions is seen by the Ells River having higher loads than the Steepbank River. Using the Ells and Steepbank as examples, double plot PACs ratios suggest that the PAC concentrations and signatures vary spatially within the MF but that the weathering processes may be the same. Plots of the various homologs of PACs generally illustrated a normal distribution which suggests petrogenic origins. However, several PAC ratios suggested that both the parent material and the SS are pyrogenic in nature. While it is likely that some level of atmospheric deposition (anthropogenic or from forest fire) is incorporated into the SS of the rivers, it is likely to be limited relative to the proportion of naturally eroded MF sediments. Additional analysis will be needed to distinguish the relative risk of both anthropogenic (e.g., industrial operations) and natural sources (bitumen deposits, forest fire) of PACs to the SS and to long-range depositional environments, as they may have potential aquatic ecological effects.


Subject(s)
Geologic Sediments/chemistry , Oil and Gas Fields , Polycyclic Aromatic Hydrocarbons/analysis , Water Pollutants, Chemical/analysis , Canada , Rivers/chemistry
9.
Wetl Ecol Manag ; 26(3): 331-343, 2018.
Article in English | MEDLINE | ID: mdl-30996517

ABSTRACT

The emergent aquatic plant, Sagittaria cuneata, is an easily-identified and commonly-found species in the Great Plains region of North America and has the potential to be a bioindicator of nitrogen (N) and phosphorus (P) because of its previously-identified leaf plasticity in response to nutrient conditions. To identify associations between leaf morphology and soil and water nutrients, we conducted: (1) a 10-week controlled experiment in which plants were grown in nutrient-enriched sediment, nutrient-enriched water, or unamended control trials, and (2) a field study where emergent leaves were collected from 15 streams of varying nutrient concentrations. Plants grown in experimentally enriched sediment were more productive than those grown in enriched water or control conditions: they produced more emergent leaves and tubers, had a larger final biomass and height, and developed emergent leaves that showed a consistent increase in size and unique change in shape over time. Emergent leaves collected from field plants also showed significant variability of leaf traits; however, this variability occurred at all scales of replication (leaf, plant, quadrat, and site), with linear mixed effects modelling indicating that random chance was likely driving this variability. Although sediment nutrients were crucial to successful growth of S. cuneata under controlled conditions, the high variability in leaf morphology under field conditions (likely due to large natural variability at the species, population, and individual scale) make leaf plasticity of S. cuneata unsuitable as a bioindicator. Our results emphasize the need to quantify within and among plant variation in leaf morphology (and to clarify sampling methods) for the many taxa of aquatic macrophytes that are phenotypically plastic and notoriously difficult to classify.

10.
Open Access Emerg Med ; 8: 47-55, 2016.
Article in English | MEDLINE | ID: mdl-27471415

ABSTRACT

Asthma is one of the most common chronic pediatric diseases. Patients with asthma often present to the emergency department for treatment for acute exacerbations. These patients may not have a primary care physician or primary care home, and thus are seeking care in the emergency department. Asthma care in the emergency department is multifaceted to treat asthma patients appropriately and provide quality care. National and international guidelines exist to help drive clinical care. Electronic and paper-based tools exist for both physicians and patients to help improve emergency, home, and preventive care. Treatment of patients with asthma should include the acute exacerbation, long-term management of controller medications, and controlling triggers in the home environment. We will address the current state of asthma research in emergency medicine in the US, and discuss some of the resources being used to help provide a medical home and improve care for patients who suffer from acute asthma exacerbations.

11.
Int J Environ Res Public Health ; 10(3): 1020-36, 2013 Mar 12.
Article in English | MEDLINE | ID: mdl-23481592

ABSTRACT

Enterococcus spp. from two poultry farms and proximate surface and ground water sites in an area of intensive poultry production were tested for resistance to 16 clinical antibiotics. Resistance patterns were compared to assess trends and possible correlations for specific antimicrobials and levels of resistance. Enterococci were detected at all 12 surface water sites and three of 28 ground water sites. Resistance to lincomycin, tetracycline, penicillin and ciprofloxacin in poultry litter isolates was high (80.3%, 65.3%, 61.1% and 49.6%, respectively). Resistance in the surface water to the same antibiotics was 87.1%, 24.1%, 7.6% and 12.9%, respectively. Overall, 86% of litter isolates, 58% of surface water isolates and 100% of ground water isolates were resistant to more than one antibiotic. Fifty-four different resistance patterns were recognised in isolates obtained from litter and environmental samples and several E. faecium and E. faecalis isolates from litter and environment samples shared the same resistance pattern. Multiple antibiotic resistant (MAR) indices calculated to assess health risks due to the presence of resistant enterococci suggested an increased presence of antibiotics in surface water, likely from poultry sources as no other wastewater contributions in the area were documented.


Subject(s)
Animal Husbandry , Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial , Enterococcus/drug effects , Poultry , Animals , Enterococcus/isolation & purification , Environmental Monitoring , Microbial Sensitivity Tests , Soil Pollutants/isolation & purification , Water Pollutants/isolation & purification
12.
Microb Ecol ; 64(2): 378-87, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22383122

ABSTRACT

Genetic relatedness of enterococci from poultry litter to enterococci from nearby surface water and groundwater in the Lower Fraser Valley regions of British Columbia, Canada was determined. A new automated BOX-PCR and Pulsed-Field Gel Electrophoresis (PFGE) were used to subtype enterococcal isolates from broiler and layer litter and surface and groundwater. All surface water samples (n = 12) were positive for enterococci, as were 11% (3/28) of groundwater samples. Enterococcus faecium (n = 90) was isolated from all sources, while Enterococcus faecalis (n = 59) was isolated from all sources except layer litter. The majority of E. faecalis originated from broiler litter (28/59; 47.5%) while the majority of E. faecium were isolated from layer litter (29/90; 32.2%). E. faecalis grouped primarily by source using BOX-PCR. Isolates from water samples were dispersed more frequently among PFGE groups containing isolates from poultry litter. E. faecium strains were genetically diverse as overall clustering was independent of source by both molecular methods. Subgroups of E. faecium isolates based upon source (layer litter) were present in BOX-PCR groups. Three individual E. faecalis groups and two individual E. faecium groups were 100% similar using BOX-PCR; only one instance of 100% similarity among isolates using PFGE was observed. Although enterococci from litter and water sources were grouped together using BOX-PCR and PFGE, isolates originating from water could not be definitively identified as originating from poultry litter. Automation of BOX-PCR amplicon separation and visualization increased the reproducibility and standardization of subtyping using this procedure.


Subject(s)
Electrophoresis, Gel, Pulsed-Field/methods , Enterococcus/classification , Feces/microbiology , Fresh Water/microbiology , Polymerase Chain Reaction/methods , Poultry , Animal Husbandry , Animals , Bacterial Typing Techniques , British Columbia , Cluster Analysis , Enterococcus/genetics , Enterococcus/isolation & purification , Enterococcus faecalis/classification , Enterococcus faecalis/genetics , Enterococcus faecalis/isolation & purification , Enterococcus faecium/classification , Enterococcus faecium/genetics , Enterococcus faecium/isolation & purification , Environmental Monitoring/methods , Genetic Variation , Reproducibility of Results , Sensitivity and Specificity
13.
J Environ Qual ; 41(1): 7-20, 2012.
Article in English | MEDLINE | ID: mdl-22218169

ABSTRACT

Inputs of nutrients (P and N) to freshwaters can cause excessive aquatic plant growth, depletion of oxygen, and deleterious changes in diversity of aquatic fauna. As part of a "National Agri-Environmental Standards Initiative," the Government of Canada committed to developing environmental thresholds for nutrients to protect ecological condition of agricultural streams. Analysis of data from >200 long-term monitoring stations across Canada and detailed ecological study at ~70 sites showed that agricultural land cover was associated with increased nutrient concentrations in streams and this, in turn, was associated with increased sestonic and benthic algal abundance, loss of sensitive benthic macroinvertebrate taxa, and an increase in benthic diatom taxa indicative of eutrophication. Chemical thresholds for N and P were defined by applying five approaches, employing either a predetermined percentile to a water chemistry data set or a relationship between water chemistry and land cover, to identify boundaries between minimally disturbed and impaired conditions. Comparison of these chemical thresholds with biological thresholds (derived from stressor-response relationships) produced an approach for rationalizing these two types of thresholds and deriving nutrient criteria. The resulting criteria were 0.01 to 0.03 mg L(-1) total P and 0.87-1.2 mg L(-1) total N for the Atlantic Maritime, 0.02 mg L(-1) total P and 0.21 mg L(-1) total N for the Montane Cordillera, ~0.03 mg L(-1) total P and ~1.1 mg L(-1) total N for the Mixedwood Plains, and ~0.10 mg L(-1) total P and 0.39-0.98 mg L(-1) total N for the interior prairies of Canada. Adoption of these criteria should result in greater likelihood of good ecological condition with respect to benthic algal abundance, diatom composition, and macroinvertebrate composition.


Subject(s)
Environmental Monitoring/standards , Nitrogen/chemistry , Phosphorus/chemistry , Rivers/chemistry , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/standards , Agriculture , Ecosystem , Environmental Monitoring/methods , Eutrophication
14.
Water Res ; 46(4): 1079-92, 2012 Mar 15.
Article in English | MEDLINE | ID: mdl-22197263

ABSTRACT

The effects of agricultural activities on stream water quality were assessed by nitrogen analysis, further investigated by gas chromatography mass spectrometry (GC-MS) sterol analysis (including chemometric analysis), and characterized by bacterial source tracking (BST). Surface water samples were collected from five sites, throughout the agriculturally-influenced Nathan Creek watershed, British Columbia, Canada and a nearby control site between October 2005 and March 2006. From a total of 48 samples, Canadian Water Quality Guidelines were exceeded nineteen times for nitrate (NO3-; guideline value: 2.94 mg/L N) and four times for un-ionized ammonia (NH3; guideline value 0.019 mg/L N). Gas chromatography mass spectrometry single ion monitoring (GC-MS SIM) analysis of 18 sterols showed that five fecal sterols (coprostanol, episoprostanol, cholesterol, cholestanol, desmosterol) were detected at all sites except the control site (where only cholesterol, cholestanol and desmosterol were detected). Three phytosterols (campesterol, stigmasterol and ß-sitosterol) were also detected at all sites while the hormone estrone was present at one site on two occasions at concentrations of 0.01 and 0.04 µg/L. Chemometric analysis (principal component analysis and cluster analysis) grouped sites based on their similarities in sterol composition. Analysis of ten sterol ratios (seven for identifying human fecal contamination and four for differentiating sources of fecal contamination) showed multiple instances of human and animal contamination for every site but the control site. Application of a Bacteroides-BST method confirmed contamination from ruminant animals, pigs and dogs in varying combinations at all impact sites. Together, these results confirmed the impact of agricultural activities on the Nathan Creek watershed and support a need for better land management practices to protect water quality and aquatic life.


Subject(s)
Bacteroides/isolation & purification , Environmental Monitoring/methods , Nitrogen/isolation & purification , Sterols/isolation & purification , Water Microbiology , Water Pollution/analysis , Water Quality/standards , Animals , British Columbia , Cluster Analysis , Humans , Limit of Detection , Livestock , Principal Component Analysis , Rivers/chemistry , Rivers/microbiology , Surface Properties
15.
Pediatr Emerg Care ; 27(11): 1009-13, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22068058

ABSTRACT

BACKGROUND: Vulnerable child syndrome (VCS) describes children perceived to be at risk for behavioral, developmental, or medical problems. Families with the dynamics of VCS overuse health care resources with frequent visits to doctors' offices. OBJECTIVE: The objective of the study was to explore the relationship between VCS, parental perception of child vulnerability (PPCV), and frequency of emergency department (ED) visits. DESIGN/METHODS: Parents of patients 1 to 15 years old presenting with nonurgent complaints to a pediatric ED were eligible. Participants completed questionnaires in which the Vulnerable Child Scale was used to generate a measure of PPCV. Primary outcomes included number of ED visits and PPCV assignment. Children were divided into 2 PPCV groups by Vulnerable Child Scale score: less than 40 (high PPCV) versus 40 or greater (low PPCV). The cutoff point was chosen as 1 SD (7.3) from the sample mean (46.8) on the vulnerable end of the scale (low scores). RESULTS: The mean ages of the 351 parents and children were 30 (SD, 7.7) years and 5 (SD, 3.9) years, respectively; 17% of children had high PPCV. Eleven variables differed statistically between subjects with high and low PPCV including number of ED visits and hospital admissions, excellent reported child health, pregnancy problems, delivery problems, child mental health problems, parent mental health problems, and child developmental problems. CONCLUSIONS: Our results reveal that children with higher PPCV had an increased number of ED visits, and risk factors for higher perceived vulnerability scores were identified. Future investigation on ways to intervene with families with the dynamics of VCS may be warranted.


Subject(s)
Child Welfare , Emergency Service, Hospital/statistics & numerical data , Parents/psychology , Adolescent , Adult , Child , Child Behavior Disorders/epidemiology , Child, Preschool , Developmental Disabilities/epidemiology , Fear , Female , Humans , Infant , Male , Mental Disorders/epidemiology , Ohio/epidemiology , Parent-Child Relations , Patient Admission/statistics & numerical data , Physicians/psychology , Pregnancy , Pregnancy Complications/epidemiology , Severity of Illness Index , Social Perception , Surveys and Questionnaires , Syndrome
16.
Water Sci Technol ; 64(8): 1590-6, 2011.
Article in English | MEDLINE | ID: mdl-22335100

ABSTRACT

Small watersheds in the Canadian Prairies are characterized by seasonally disconnected hydrologic networks whereby stream channels are hydrologically connected during snowmelt but have disconnected reaches throughout the remainder of the year. Snowmelt is the most significant hydrological event in the Canadian Prairies, yet few studies have investigated the role of snowmelt in the nutrient budget of prairie streams. We quantified hydrologic and nutrient dynamics during snowmelt for ten agricultural subwatersheds distributed along a gradient of human activity in the Red River Valley, Canada, to evaluate the timing of nitrogen (N) and phosphorus (P) export. Elevated concentrations of total P (TP) and total N (TN) were observed during the snowmelt peak, with maximum concentrations reaching 3.23 mg TP L(-1) and 18.50 mg TN L(-1). Dissolved P and N dominated the total nutrient pool throughout snowmelt, likely due to reduced erosion and sediment transport resulting from the combination of the flat topography, frozen soil and stream banks, and gradual snow cover melt. Significant correlations were observed between snowmelt N load (r=0.91; p<0.05) and both agricultural land cover and fertilizer usage, with a weaker correlation between snowmelt P load (r=0.81; p<0.05) and agricultural area. Our results showed that snowmelt plays a key role in nutrient export to prairie aquatic ecosystems and this may have serious impacts on downstream ecosystems. Land use management practices need to consider the snowmelt period to control nutrient loads to Lake Winnipeg and other waterbodies in the Great Plains.


Subject(s)
Ecosystem , Nitrogen/chemistry , Rivers/chemistry , Snow/chemistry , Canada , Human Activities , Phosphorus , Seasons , Time Factors , Water Movements
19.
J Environ Sci Health B ; 44(7): 717-23, 2009 Sep.
Article in English | MEDLINE | ID: mdl-20183082

ABSTRACT

Pharmaceuticals are emerging contaminants with potential risks to the environment and human health. A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed for determination of the antimicrobials virginiamycin, monensin, salinomycin, narasin and nicarbazin in poultry litter and soil. This method involves methanol extraction and clean-up of extracts through glass microfibre filters, introduction of the extracts and separation of compounds on a Zorbax Eclipse XDB C8 column, and compound detection in a Quattro Micro Micromass spectrometer. For litter samples, Method Detection Limits ranged from 0.1-0.6 microg Kg(-1), while Limits of Quantitation (LOQs) were 2, 1, 0.4, 1 and 2 microg Kg(-1) for virginiamycin, monensin, salinomycin, narasin and nicarbazin, respectively. For soil samples calculated LOQs were 2, 3, 1, 1, and 1 microg Kg(-1) for virginiamycin, monensin, salinomycin, narasin and nicarbazin, respectively. Application of the LC-MS-MS method for detection of veterinary pharmaceuticals in litter collected from commercial poultry farms showed that compounds were present at concentrations ranging from 10-11,000 microg Kg(-1).


Subject(s)
Chemical Fractionation/methods , Manure/analysis , Poultry , Soil/analysis , Veterinary Drugs/analysis , Animals , Chromatography, High Pressure Liquid/methods , Glass/chemistry , Humans , Limit of Detection , Methanol/chemistry , Tandem Mass Spectrometry/methods
20.
Water Sci Technol ; 58(11): 2203-10, 2008.
Article in English | MEDLINE | ID: mdl-19092197

ABSTRACT

Inputs of nutrients (phosphorus, P, and nitrogen, N) to coastal and fresh waters can accelerate eutrophication, resulting in excessive aquatic plant growth, depletion of oxygen, and deleterious changes in abundance and diversity of organisms. Using long-term (approximately 1995-2005) monitoring data from agriculturally-dominated watersheds in southern Ontario and Quebec, Canada, we developed and tested several approaches for setting targets for N and P. Our research showed that it is possible to set scientifically-credible targets for total P and total N to protect ecological condition of streams in agricultural landscapes, and define achievable targets attainable following adoption of beneficial management practices.


Subject(s)
Agriculture , Ecosystem , Eutrophication , Nitrogen/analysis , Phosphorus/analysis , Rivers/chemistry , Calibration , Canada , Eukaryota/metabolism , Geography
SELECTION OF CITATIONS
SEARCH DETAIL
...