Impacts of colonization on Indigenous food systems in Canada and the United States: a scoping review.

BACKGROUND: Indigenous populations in Canada and the United States (US) have maintained reciprocal relationships with nature, grounded in respect for and stewardship of the environment; however, disconnection from traditional food systems has generated a plethora of physical and mental health challenges for communities. Indigenous food sovereignty including control of lands were found to be factors contributing to these concerns. Therefore, our aim was to conduct a scoping review of the peer-reviewed literature to describe Indigenous disconnection from Indigenous food systems (IFS) in Canada and the US. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-SR) and Joanna Briggs Institute guidelines, we searched MEDLINE, SCOPUS, International Bibliography of the Social Sciences, Sociological Abstracts, and Bibliography of Native North Americans. Data was extracted from 41 studies and a narrative review completed based on study themes. RESULTS: The overarching theme identified in the included studies was the impact of colonization on IFS. Four sub-themes emerged as causes for Indigenous disconnection from traditional food systems, including: climate change; capitalism; legal change; and socio-cultural change. These sub-themes highlight the multiple ways in which colonization has impacted Indigenous food systems in Canada and the US and important areas for transformation. CONCLUSIONS: Efforts to reconnect Indigenous knowledge and values systems with future food systems are essential for planetary health and sustainable development. Traditional knowledge sharing must foreground authentic Indigenous inclusion within policymaking.

Human health impacts of exposure to phthalate plasticizers: An overview of reviews.

In this review of reviews, we overview the current global body of available evidence from structured reviews of epidemiological studies that explore human health outcomes associated with exposure to phthalates (chemical plasticisers commonly found in plastics). We found robust evidence for an association with lower semen quality, neurodevelopment and risk of childhood asthma, and moderate to robust evidence for impact on anogenital distance in boys. We identified moderate evidence for an association between phthalates/metabolites and low birthweight, endometriosis, decreased testosterone, ADHD, Type 2 diabetes and breast/uterine cancer. There was some evidence for other outcomes including anofourchette distance, fetal sex hormones, pre-term birth, lower antral follicle count, reduced oestrodiol, autism, obesity, thyroid function and hearing disorders. We found no reviews of epidemiological human studies on the impact of phthalates from recycled plastics on human health. We recommend that future research should use urine samples as exposure measures, consider confounders in analyses and measure impacts on female reproductive systems. Our findings align with emerging research indicating that health risks can occur at exposure levels below the "safe dose" levels set out by regulators, and are of particular concern given potential additive or synergistic "cocktail effects" of chemicals. This raises important policy and regulatory issues for identifying and controlling plastics and health related impacts and highlights a need for more research into substances of concern entering plastics waste streams via recycling.

Microplastics in marine mammals stranded around the British coast: ubiquitous but transitory?

Plastic pollution represents a pervasive and increasing threat to marine ecosystems worldwide and there is a need to better understand the extent to which microplastics (<5 mm) are ingested by high trophic-level taxa, such as marine mammals. Here, we perform a comprehensive assessment by examining whole digestive tracts of 50 individuals from 10 species whilst operating strict contamination controls. Microplastics were ubiquitous with particles detected in every animal examined. The relatively low number per animal (mean = 5.5) suggests these particles are transitory. Stomachs, however, were found to contain a greater number than intestines, indicating a potential site of temporary retention. The majority of particles were fibres (84%) while the remaining 16% was fragments. Particles were mainly blue and black (42.5% and 26.4%) in colour and Nylon was the most prevalent (60%) polymer type. A possible relationship was found between the cause of death category and microplastic abundance, indicating that animals that died due to infectious diseases had a slightly higher number of particles than those that died of trauma and other drivers of mortality. It is not possible, however, to draw any firm conclusions on the potential biological significance of this observation and further research is required to better understand the potential chronic effects of microplastic exposure on animal health, particularly as marine mammals are widely considered important sentinels for the implications of pollution for the marine environment.

Method for assessing the chronic toxicity of marine and estuarine sediment-associated contaminants using the amphipod Corophium volutator.

Acute sediment toxicity tests do not test key life stage events such as moulting and reproduction and therefore do not reveal the longer-term effects of contaminant exposure. A laboratory method is described for determining the chronic toxicity of contaminants associated with whole sediments. The test is conducted using neonates of the estuarine amphipod Corophium volutator at 15 degrees C, salinity 25 psu and a 12 h light:12 h dark photoperiod. The endpoints are survival and growth after 28 days and survival, growth and reproduction of amphipods upon termination of test i.e. reproduction within all control vessels (ca 75 days). The sediment chronic toxicity test was used to investigate the effects of sediments spiked with environmentally relevant preparations of slightly weathered Alaskan North Slope crude oil, including a water-accommodated-fraction (WAF) and a chemically-dispersed (Corexit 9527) WAF. Sediment oil concentrations were quantified using ultra-violet fluorescence. The amphipods exposed to chemically dispersed oil had higher mortality and lower growth rates than control-, Corexit 9527- and WAF-exposed organisms, resulting in reduced reproduction. The described method supplements the standard acute sediment test and would be particularly useful when long-term ecological effects are suspected but acute tests reveal no significant mortality. The sediment chronic test reported herein has shown that sediment that was not evidently toxic during 10-day acute tests could have population-level effects on sediment-dwelling amphipods.

Sublethal impact of short term exposure to the organophosphate pesticide azamethiphos in the marine mollusc Mytilus edulis.

Concern has been raised that the increased use of pesticides in intensive aquaculture practices may cause adverse sublethal effects to non-target aquatic species. Azamethiphos is an organophosphate (OP) pesticide used to combat sea lice infestations in farmed salmonids. Here, the sublethal impact on the blue mussel, Mytilus edulis, of short term exposure to azamethiphos was determined. The testing regime included biomarkers of exposure (acetylcholinesterase activity), cytotoxicity (neutral red retention), immune function (phagocytic index) and physiological condition (feeding rate). The distribution and sensitivity of M. edulis acetylcholinesterase to inhibition by azamethiphos was first determined, yielding IC(50) values of 0.736 and 1.30 mg l(-1) for gill and haemolymph, respectively. Exposure of mussels to 0.1 mg l(-1) azamethiphos for periods of up to 24h caused a significant reduction in acetylcholinesterase activity in both the haemolymph (P<0.0002) and the gill (P<0.002), alteration in cell viability (P<0.02) and decrease in phagocytic index (P<0.03). The feeding rate remained unaffected. The results support the hypothesis that, in addition to its neurotoxic effects, azamethiphos can modulate haemocyte function and immune defence in M. edulis at environmentally relevant concentrations after only a few hours.

Marine anthropogenic litter on British beaches: A 10-year nationwide assessment using citizen science data.

Growing evidence suggests that anthropogenic litter, particularly plastic, represents a highly pervasive and persistent threat to global marine ecosystems. Multinational research is progressing to characterise its sources, distribution and abundance so that interventions aimed at reducing future inputs and clearing extant litter can be developed. Citizen science projects, whereby members of the public gather information, offer a low-cost method of collecting large volumes of data with considerable temporal and spatial coverage. Furthermore, such projects raise awareness of environmental issues and can lead to positive changes in behaviours and attitudes. We present data collected over a decade (2005-2014 inclusive) by Marine Conservation Society (MCS) volunteers during beach litter surveys carried along the British coastline, with the aim of increasing knowledge on the composition, spatial distribution and temporal trends of coastal debris. Unlike many citizen science projects, the MCS beach litter survey programme gathers information on the number of volunteers, duration of surveys and distances covered. This comprehensive information provides an opportunity to standardise data for variation in sampling effort among surveys, enhancing the value of outputs and robustness of findings. We found that plastic is the main constituent of anthropogenic litter on British beaches and the majority of traceable items originate from land-based sources, such as public littering. We identify the coast of the Western English Channel and Celtic Sea as experiencing the highest relative litter levels. Increasing trends over the 10-year time period were detected for a number of individual item categories, yet no statistically significant change in total (effort-corrected) litter was detected. We discuss the limitations of the dataset and make recommendations for future work. The study demonstrates the value of citizen science data in providing insights that would otherwise not be possible due to logistical and financial constraints of running government-funded sampling programmes on such large scales.

Ixodes scapularis ticks collected by passive surveillance in Canada: analysis of geographic distribution and infection with Lyme borreliosis agent Borrelia burgdorferi.

Passive surveillance for the occurrence of the tick Ixodes scapularis Say (1821) and their infection with the Lyme borreliosis spirochaetes Borrelia burgdorferi s.l. has taken place in Canada since early 1990. Ticks have been submitted from members of the public, veterinarians, and medical practitioners to provincial, federal, and university laboratories for identification, and the data have been collated and B. burgdorferi detected at the National Microbiology Laboratory. The locations of collection of 2,319 submitted I. scapularis were mapped, and we investigated potential risk factors for I. scapularis occurrence (in Quebec as a case study) by using regression analysis and spatial statistics. Ticks were submitted from all provinces east of Alberta, most from areas where resident I. scapularis populations are unknown. Most were adult ticks and were collected in spring and autumn. In southern Québec, risk factors for tick occurrence were lower latitude and remote-sensed indices for land cover with woodland. B. burgdorferi infection, identified by conventional and molecular methods, was detected in 12.5% of 1,816 ticks, including 10.1% of the 256 ticks that were collected from humans and tested. Our study suggests that B. burgdorferi-infected I. scapularis can be found over a wide geographic range in Canada, although most may be adventitious ticks carried from endemic areas in the United States and Canada by migrating birds. The risk of Lyme borreliosis in Canada may therefore be mostly low but more geographically widespread than previously suspected.

Antitumor effects of granulocyte-macrophage colony-stimulating factor production by melanoma cells.

The use of immunomodulating gene therapy in the treatment of malignant disease is under intensive investigation. In this study, we examined the potential of melanoma-derived granulocyte-macrophage colony-stimulating factor (GM-CSF) to inhibit melanoma progression in a murine model. The HGH18 murine melanoma cell line was transfected with the murine GM-CSF gene in a SV40 expression vector that resulted in melanoma clones that produced varying amounts of GM-CSF. Syngeneic mice inoculated s.c. with HFH18 parental melanoma cells or HFH18 cells transfected with the GM-CSF gene n the noncoding 3'-5' orientation [HFH18/GM-CSF(-) cells] develop large tumors that reach a mean tumor volume of 3300 mm3 by day 30. In contrast, animals inoculated with two melanoma clones producing high levels of GM-CSF [HFH18/GM-CSF(++) and HFH18/GM-CSF(+ + +)] either completely reject the tumor cells or develop tumors with a mean volume of only 40 mm3. In comparison, animals inoculated with a melanoma clone producing low levels of GM-CSF [HFH18/GM-CSF(+)] develop large tumors averaging 2000 mm3, thus demonstrating a dose-response effect of tumor inhibition by melanoma-derived GM-CSF. Additionally, vaccination with irradiated GM-CSF-producing melanoma cells conferred optimal immunogenicity against a subsequent challenge with HFH18 cells. Tissue sections from excised GM-CSF-producing tumor cell inoculation sites but not from HFH18 parental or HFH18/GM-CSF(-) inoculation sites demonstrate a dense inflammatory infiltrate composed of neutrophils, tissue macrophages, and numerous CD4- and CD8-positive lymphocytes but few melanoma cells. Large numbers of dendritic cells and cells expressing the B7-2 costimulatory molecule are detected only within HFH18/GM-CSF(+ + +) melanoma inoculation sites. Our results lend further support to clinical trials of GM-CSF gene therapy in the treatment of advanced malignant melanoma, possibly by the recruitment of dendritic antigen-presenting cells.

Time clustering of high titre insulin autoantibodies (IAA) in the cord blood of infants born to non-diabetic mothers.

Insulin autoantibodies (IAA) are markers for autoimmune insulitis, and are reported in up to 100% of diabetic children before the age of five years, but in fewer than 1% of their controls. Their origins are unknown. In this report a cluster of high titre IAA in cord blood is reported, distinct from the low titre 'non-specific' binding previously described. The distributions of displaceable insulin binding measured in adults (Group A, n = 79), adolescents (Group B, n = 19), primary school children (Group C, n = 32) and third trimester pregnant women (Group D, n = 60) were all unimodal, normal and not different from each other (A = 0.57+/-0.64%, B = 0.87+/-0.45%, C = 0.81+/-0.87% and D = 0.35+/-0.48%). The distribution of insulin binding in the cord sera of consecutive newborns (n = 428) born between October and the following May, however, was bimodal. The first distribution, included 400 sera, was symmetrical and not different (0.79+/-0.45%) from groups A, B, C and D. The second distribution comprised the remaining 28 sera (7% of the total sample) with insulin-displaceable binding values in an IDW-validated radio assay ranging from 2.2% to 31.1%. The appearance of IAA was not HLA-restricted, but the frequency of IAA+ samples was seen to vary over five consecutive months. The timing is consistent with acute viral infection, but the implications for future insulin dependent diabetes will await long-term follow-up of the children and mothers involved.

Inhibition of murine melanoma growth by granulocyte-macrophage colony stimulating factor gene transfection is not haplotype specific.

Granulocyte-macrophage colony stimulating factor (GM-CSF) has been shown to inhibit the growth and progression of murine melanoma cells in syngeneic C57BL/6 (H-2b) recipient animals. We now demonstrate that this effect is not specific to melanomas derived from a single strain of mice by examining the subcutaneous growth of K1735 murine melanoma cells (H-2k) transfected with GM-CSF in a syngeneic mouse model. Non-GM-CSF-secreting melanoma cells (parental K1735 and K1735 cells transfected with the GM-CSF gene in antisense orientation) generated tumours that reached a mean volume of 4000 mm3 30-40 days, with a mean survival of 40 days after tumour cell injection. In contrast, 90% of the mice injected with three different clones of GM-CSF-producing K1735 melanomas developed no measurable tumours and were healthy and tumour-free when followed for over 300 days post-inoculation. Additionally, mice injected with GM-CSF-secreting K1735 cells developed long-lasting immunity to the parental melanoma cell line challenge in vivo. A dense neutrophilic and lymphocytic inflammatory infiltrate as well as large numbers of dendritic cells were detected only at the inoculation sites of the GM-CSF-producing melanoma cells. Thus, these studies demonstrate for the first time that GM-CSF inhibits melanoma growth in a second genetically distinct MHC tumour-host model system and further support the use of GM-CSF in clinical trials in the treatment of advanced malignant melanoma in humans.

Seasonal occurrence and reproductive status of Opisocrostis bruneri (Siphonaptera: Ceratophyllidae), a flea on Franklin's ground squirrel, Spermophilus franklinii (Rodentia: Sciuridae) near Birds Hill Park, Manitoba.

Eight hundred and forty-nine and 1,503 Opisocrostis bruneri (Baker) were removed from Spermophilus franklinii (Sabine) in 1982 and 1983, respectively. Two discrete peaks in mean intensity of infestation were observed, one in early May and one in late August to early September. Overall prevalence of O. bruneri on S. franlinii was > or = 0.75. The observed biweekly prevalence on adult male and female squirrels was always > or = 0.73 and > or = 0.67, respectively. All juvenile squirrels were infested. Female fleas with undeveloped ovarioles, and with or without sperm in the spermatheca, were predominant during the first 6 wk that squirrels appeared above ground after hibernation. Parous females predominated thereafter. Peaks of nulliparous female fleas were observed in early May and early July. Female fleas were favored in each trapping period except during a 2-wk period from the beginning of May to the end of June. The mean biweekly sex ratio (male/female) of fleas removed from S. franklinii was 0.70 and 0.72 in 1982 and 1983, respectively. Oogenesis in O. bruneri was not dependent upon the estrous cycle of female S. franklinii. It appeared that O. bruneri completed at least two generations per year in Manitoba.

Reproductive status of four species of fleas (Insecta: Siphonaptera) on Richardson's ground squirrels (Rodentia: Sciuridae) in Manitoba, Canada.

To test the hypothesis that oogenesis in 4 species of fleas is dependent on the reproductive cycle of their monoestrous host Spermophilus richardsonii, 6,416 Oropsylla (Oropsylla) rupestris (Baker), 5,893 Oropsylla (Opisocrostis) bruneri (Baker), 813 Neopsylla inopina (Rothschild), and 223 Rhadinopsylla (Actenophthalmus) fraterna (Baker) females were collected from active hosts at 3 locations in Manitoba during 1987, 1988, and 1989 and dissected. Based on morphological changes in the ovaries, female fleas were categorized as immature, nulliparous or parous. Nulliparous N. inopina predominated in April and early May. Immature and nulliparous O. bruneri predominated throughout April and May. Nulliparous O. rupestris were most prevalent in early June but occurred sporadically throughout the season. Nulliparous R. fraterna predominated only in April. The percentage of mated females was usually correlated with percentage parity for all species. Oogenesis in each of the 4 flea species was apparently independent of the reproductive cycle of their host. Female fleas of all reproductive categories were frequently collected before, during, and following reproduction in their hosts.

Characterisation of nitric oxide synthase activity in the tropical sea anemone Aiptasia pallida.

The presence of nitric oxide synthase (EC 1.14.23 NOS) activity is demonstrated in the tropical marine cnidarian Aiptasia pallida (Verrill). Enzyme activity was assayed by measuring the conversion of [3H]arginine to [3H]citrulline. Optimal NOS activity was found to require NADPH. Activity was inhibited by the competitive NOS inhibitor NG-methyl-L-arginine (L-NMA), but not the arginase inhibitors L-valine and L-ornithine. NOS activity was predominantly cytosolic, and was characterised by a Km for arginine of 19.05 microM and a Vmax of 2.96 pmol/min per microgram protein. Histochemical localisation of NOS activity using NADPH diaphorase staining showed the enzyme to be predominantly present in the epidermal cells and at the extremities of the mesoglea. These results provide a preliminary biochemical characterisation and histochemical localisation of NOS activity in A. pallida, an ecologically important sentinel species in tropical marine ecosystems.

Differential sensitivity of three marine invertebrates to copper assessed using multiple biomarkers.

Understanding how biomarkers relate to each other on exposure to particular contaminants in different species is key to their widespread application in environmental management. However, few studies have systematically used multiple biomarkers in more than a single species to determine the variability of sublethal effects of a particular contaminant. In this study, three marine invertebrates, the shore crab Carcinus maenas, the common limpet Patella vulgata and the blue mussel Mytilus edulis, were exposed over 7 days in the laboratory to environmentally realistic concentrations of the priority pollutant copper. A combination of molecular, cellular and physiological biomarkers was measured in each organism to detect the toxic effects of copper. Biomarkers included lysosomal stability (neutral red retention), neurotoxicity (acetylcholinesterase activity), metabolic impairment (total haemolymph protein), physiological status (heart rate) and induction of protective metallothionein proteins. P. vulgata was the most sensitive to copper with significant effects measured in all biomarkers at concentrations of 6.1 microg Cu l(-1). In C. maenas, cellular and neurotoxic endpoints were affected significantly only at 68.1 microg Cu l(-1). Exposure to copper also induced metallothionein production in crabs. Over a 7-day exposure period, M. edulis was the most tolerant species to copper with significant effects being observed at the cellular level only at 68.1 microg Cu l(-1) . In all three species, cellular and neurotoxic pathways were more sensitive to disruption than physiological processes (protein and heart rate). Results illustrate how a suite of biomarkers applied to different sentinel species can provide a 'diagnosis of stress', whereby, effects at the molecular level can be used to interpret the level of physiological impairment of the organism.

Neuro-endocrine biomarkers of pollution-induced stress in marine invertebrates.

Nitric oxide (NO) is a molecular mediator of the non-specific immune response of vertebrates but production has also been recorded in response to bacterial infection in invertebrates. Together with biogenic amines and cytokines, production of NO in invertebrate phagocytic haemocytes is thought to represent a putative stress response. In this study the hypothesis that NO might be a sensitive biomarker of stress in invertebrates has been tested. The spectrophotometric Griess assay for nitrite and nitrate has been modified so that the final breakdown products of NO are suitable for measurement in invertebrate haemolymph. The assay was linear in the range 1-100 microM with a sensitivity of 4 microM. The baseline NOx measurement in unstressed mussels was 0.74 mM NOx/mg protein. Mytilus edulis were kept at 15 micro C in filtered seawater for at least 2 days prior to exposure to TBTO (0.001-0.1 mg/l) for 24 h. Preliminary results suggest that TBTO perturbs the NO response and that the outlined assay protocol is a sensitive means of detecting those changes. It is proposed that NO measurements potentially offer a highly sensitive, non-invasive means of monitoring stress responses associated with environmental change.

Detecting a field gradient of PAH exposure in decapod crustacea using a novel urinary biomarker.

Norwegian coastal waters are subject to PAH contamination from electrochemical industries such as aluminium smelters. Evidence of PAH exposure has been established in fish and bivalves. The present study tests the applicability of a novel crustacean PAH exposure biomarker to a PAH contamination gradient in the field (Karmsund Strait, SW Norway). Fluorescence analysis of urine samples collected from crabs at each site revealed 1-OH pyrene "equivalent" levels (indicative of pyrogenic PAH contamination) decreased with increasing distance from a point source of pyrogenic PAH (a large aluminium works). The assay was shown to be suitable for the detection of PAH exposure in wild crustacean populations, for discriminating between contaminated and clean sites and is also sufficiently sensitive to detect gradients of PAH contamination. The method provides a rapid, inexpensive and non-destructive measure of biologically available PAH in crustaceans.

Evaluation of toxicity in tributaries of the Mersey estuary using the isopod Asellus aquaticus (L.).

Increasing numbers of industrial, agricultural and natural chemicals are present in sewage effluent and are known to elicit toxic effects in laboratory exposures, but little is known of their combined sub-lethal effect in the field. In this study, a combination of esterase activity and ventilation rate assays was performed to determine the neurological and physiological function of the freshwater crustacean Asellus aquaticus (L.) at sites above and below a sewage treatment works (STW). Cholinesterase and carboxylesterase activities were significantly inhibited (n=8, P<0.05) and ventilation rates increased (n=8, P=0.0001) in A. aquaticus at STW sites compared to those from reference sites, indicating a decrease in neurological and physiological function. The ecological relevance of these findings for the population dynamics of the organisms in the field is discussed.

Records of ectoparasites collected on ospreys from Ontario.

Ectoparasites were collected from ospreys (Pandion haliaetus) in four study areas within the Great Lakes basin of Ontario, Canada. Two parasitic mite (Acari) species, Bonnetella fusca and Analloptes sp., were collected from nestlings. One chewing louse (Mallophaga) Kurodaia haliaeeti was collected from nestlings and adults. Prevalence and intensity of K. haliaeeti were greater in the most northern of the four study areas. Bonnetella prevalence and intensity did not seem to vary greatly across the study areas. New range and host records are presented for B. fusca and Analloptes sp., respectively.

A taxonomic review of the Ceratophyllus Curtis, 1832 of North America (Siphonaptera: Ceratophyllidae: Ceratophyllinae).

The 22 North American taxa assigned to the flea genus Ceratophyllus Curtis, 1832, are reviewed. All are parasites of birds and include 17 species in the nominate subgenus, 3 in Emmareus and 2 in Celeophilus. Keys to the subgenera are provided, distinguishing characters of the individual species are discussed and illustrated and the various aspects of distribution and host preferences are cited.

Effects of temperature and photoperiod on the infection of two mosquito species by the mermithid Romanomermis culicivorax.

Successful invasion by the mermithid Romanornermis eulicivorax declined linearly from 93.6 to 1.5% in Culex tarsalis and from 73.1 to 1.6% i n Aeries dorsalis larvae exposed in the laboratory at 18, 16, 14, 12, and l 0 C. Larvae of C. tarsalis were more susceptible than those of A. dorsalis at 18 and 16 C, but this relationship was reversed at 12 C. Larval mortality during the 48-h exposure period was due primarily to nematode infection . Photoperiod had no effect on infection.