Indoor air quality in remote first nations communities in Ontario, Canada.

A recent study of the health of Indigenous children in four First Nations Communities in remote northwestern Ontario found that 21% of children had been admitted to hospital for respiratory infections before age 2 years. Here we report a detailed analysis of the housing conditions in these communities. We employed a variety of statistical methods, including linear regression, mixed models, and logistic regression, to assess the correlations between housing conditions and loadings of biocontaminants (dust mite allergens, fungal glucan, and endotoxin) and indoor concentrations of PM2.5, CO2, benzene, and formaldehyde. The houses (n = 101) were crowded with an average of approximately 7 people. Approximately 27% of the homes had sustained CO2 concentrations above 1500 ppm. Most homes had more than one smoker. Commercial tobacco smoking and the use of non-electric heating (e.g., wood, oil) were associated with increased fine particle concentrations. Over 90% of the homes lacked working Heat Recovery Ventilators (HRVs), which was associated with increased fine particle concentrations and higher CO2. Of the 101 homes, 12 had mold damage sufficient to increase the relative risk of respiratory disease. This resulted from roof leaks, through walls or around the windows due to construction defects or lack of maintenance. A similar percentage had mold resulting from condensation on windows. Endotoxin loadings were much higher than any previous study in Canada. This work provides evidence for the need for more effort to repair existing houses and to ensure the HRVs are properly installed and maintained.

Fungal bioaerosols as an occupational hazard.

PURPOSE OF REVIEW: Over the past 40 years, the circumstances where fungal bioaerosols are major issues have shifted because of changes in the industrial sector from mainly agriculture to operations, including composting, cannabis production and forestry in hot humid conditions. Changes in the design and operation of nonindustrial workplaces meant that mould and dampness became major issues that are just being reduced. This review attempts to frame that history offers a perspective on the current thinking on mechanisms and provide potentially useful sources of information for physicians and their patients. RECENT FINDINGS: The major impact of fungal exposures is not only from their allergens but also from an array of Danger-Associated Molecular Pattern molecules, possibly the most important of which is the type of glucan found in moulds that grow in damp buildings, wood chips and crops, that is beta 1, 3 D glucan in triple helical form. Located in lung epithelia, the dectin receptor is exquisitely sensitive to this compound. Except in some agricultural workplaces, low molecular weight secondary metabolites often mischaracterized as mycotoxins play little, if any, role on population health. SUMMARY: There has been a convergence in thinking between the allergy and industrial hygiene communities as well as government agencies on mould and occupational health. This has led to some useful strategies for better managing these issues as well as increasing consumer awareness.

Perceptions of Freshwater Algal Blooms, Causes and Health among New Brunswick Lakefront Property Owners.

Changes to water conditions due to eutrophication and climate change have resulted in the proliferation of algae blooms in freshwater and marine environments globally, including in Canadian lakes. We developed and administered an online survey to evaluate the awareness of these blooms and the perceptions of health risks in a sample of New Brunswick waterfront cottage and homeowners. The survey was distributed to lake and cottage associations in New Brunswick and was completed by 186 eligible respondents (18 years of age or older). Participants were asked about the water quality of their lake, awareness about algae blooms, sociodemographic and cottage characteristics, and to complete a self-rated measure of physical and mental health. While approximately 73% of participants reported that the quality of their lake water was good or very good, 41% indicated a concern about algae blooms. We found no differences in self-reported physical or mental health between those who were aware of algae blooms at their cottage and those who were not (p > 0.05). Participants expressed concerns about the impacts of algae blooms on the health of their pets, and wildlife. While climate change was the most frequently identified cause of algae blooms, there was substantial heterogeneity in the responses. In addition, the reporting of the presence and frequency of algae bloom varied between respondents who lived on the same lake. Taken together, the findings from our survey suggest that cottage owners in New Brunswick are aware and concerned about the impacts of algae blooms, however, there is a need to provide additional information to them about the occurrence and causes of these blooms.

Phytosterol oxidation products from coffee silverskin.

Coffee silverskin is a byproduct of the coffee roasting process contributing to organic waste burdens in urban areas. Silverskin is a potential source of dietary fiber, protein, carbohydrates, caffeine as well as vitamins and minerals. However, phytosterols present in the plant are susceptible to thermal oxidation resulting in the formation of phytosterol oxidation products (POPs) in the silverskin during roasting. In collaboration with a small roastery, the formation of POPs in three coffee varieties with roasting time was monitored by GC-MS. The objective was to evaluate the safety and potential benefits of incorporating coffee silverskin into value-added products. The qualitative profile of POPs in the silverskin from the three varieties was similar. Average total POPs were 0.32 g POPs/kg silverskin. POPs from the dominant plant sterol, sitosterol, were present at the highest concentrations. Caffeine, total antioxidant capacity, and total flavonoids were measured in the silverskin of the three coffees. Average values were 1.3 g caffeine/100 g silverskin, TEAC of 11 mmol Trolox/kg silverskin, and 1.94 to 8.60 mg catechin equivalent (CE)/g silverskin, respectively. An analysis of the impact of consuming teas and baked goods containing silverskin was also performed. Using published formulations, a tea or cookie containing silverskin would contribute approximately 1 and 0.3 mg POP per day, respectively. Consumption of these products would not substantially increase dietary exposure to POPs, while increasing fiber and antioxidants while reducing organic waste. PRACTICAL APPLICATION: Coffee silverskin has been studied as a possible source of fiber, antioxidants, and caffeine when incorporated in snack foods and used to make teas. To assess possible concerns about increasing dietary oxidized phytosterols, the formation of phytosterol oxidation products (POPs) was investigated in the silverskin fraction during the roasting process in three coffee varieties. In addition, caffeine, antioxidant capacity, and total flavonoids were determined. We found that silverskin can be safely used for value-added products including caffeinated teas, cookies, and bars with minimal impact on dietary POP exposures.

Housing conditions and respiratory morbidity in Indigenous children in remote communities in Northwestern Ontario, Canada.

BACKGROUND: Rates of lower respiratory tract infection (LRTI) among First Nations (FN) children living in Canada are elevated. We aimed to quantify indoor environmental quality (IEQ) in the homes of FN children in isolated communities and evaluate any associations with respiratory morbidity. METHODS: We performed a cross-sectional evaluation of 98 FN children (81 with complete data) aged 3 years or younger, living in 4 FN communities in the Sioux Lookout region of Northern Ontario. We performed medical chart reviews and administered questionnaires. We performed a housing inspection, including quantifying the interior surface area of mould (SAM). We monitored air quality for 5 days in each home and quantified the contaminant loading of settled floor dust, including endotoxin. We analyzed associations between IEQ variables and respiratory conditions using univariable and multivariable analyses. RESULTS: Participants had a mean age of 1.6 years and 21% had been admitted to hospital for respiratory infections before age 2 years. Houses were generally crowded (mean occupancy 6.6 [standard deviation 2.6, range 3-17] people per house). Serious housing concerns were frequent, including a lack of functioning controlled ventilation. The mean SAM in the occupied space was 0.2 m2. In multivariable modelling, there was evidence of an association of LRTI with log endotoxin (p = 0.07) and age (p = 0.02), and for upper respiratory tract infections, with SAM (p = 0.07) and age (p = 0.03). Wheeze with colds was associated with log endotoxin (p = 0.03) and age (p = 0.04). INTERPRETATION: We observed poor housing conditions and an association between endotoxin and wheezing in young FN children living in Northern Ontario.

Household determinants of biocontaminant exposures in Canadian homes.

Exposure to biocontaminants, such as dust mites, animal dander, bacteria, and mold, is associated with a range of health effects. This study identified household characteristics associated with indoor biocontaminant loadings in four Canadian cities. Floor dust was collected in 290 Canadian homes in Edmonton, Halifax, Montreal, and Windsor. The dust samples were analyzed for house dust mite allergens (Der f 1 and Der p 1), cat allergen (Fel d 1), cockroach allergen (Bla g 1), beta-(1,3)-D-glucan, and endotoxin. Household information was obtained through questionnaires and home inspections. We performed univariate and multivariate analyses to identify household determinants of biocontaminant loadings and mold odor presence. We observed large regional variations for all biocontaminants, except for cockroach allergen. The ranges of the contaminants measured in loadings and concentrations were similar to that of previous Canadian studies. Household characteristics including presence of carpeting, low floor cleaning frequency, older home age, presence of pets, and indoor relative humidity above 45% were positively associated with the presence of multiple indoor biocontaminants. High floor cleaning frequency and use of dehumidifiers were negatively associated with the presence of multiple indoor biocontaminants. Mold odor was positively associated with older home age, past water damage, and visible mold growth.

Intestinal toxicity of the new type A trichothecenes, NX and 3ANX.

NX and its acetylated form 3ANX are two new type A trichothecenes produced by Fusarium graminearum whose toxicity is poorly documented. The aim of this study was to obtain a general view of the intestinal toxicity of these toxins. Deoxynivalenol (DON), which differs from NX by the keto group at C8, served as a benchmark. The viability of human intestinal Caco-2 cells decreased after 24 h of exposure to 3 µM NX (-21.4%), 3 µM DON (-20.2%) or 10 µM 3ANX (-17.4%). Histological observations of porcine jejunal explants exposed for 4 h to 10 µM of the different toxins showed interstitial edema and cellular debris. Explants exposed to NX also displayed cell vacuolization, a broken epithelial barrier and high loss of villi. Whole transcriptome profiling revealed that NX, DON and 3ANX modulated 369, 146 and 55 genes, respectively. Functional analyses indicated that the three toxins regulate the same gene networks and signaling pathways mainly; cell proliferation, differentiation, apoptosis and growth, and particularly immune and pro-inflammatory responses. Greater transcriptional impacts were observed with NX than with DON. In conclusion, our data revealed that the three toxins have similar impacts on the intestine but of different magnitude: NX > DON ≫ 3ANX. NX and 3ANX should consequently be included in overall risk analysis linked to the presence of trichothecenes in our diet.

Diagnostic Fragmentation Filtering for Cyanopeptolin Detection.

Cyanobacteria are ubiquitous photosynthetic prokaryotes that produce structurally diverse bioactive metabolites. Although microcystins are extensively studied, other cyanopeptides produced by common bloom-forming species have received little attention. Cyanopeptolins are a large cyanopeptide group that contain a characteristic 3-amino-6-hydroxy-2-piperidone (Ahp) moiety. In the present study we used diagnostic fragmentation filtering (DFF), a semitargeted liquid chromatography-tandem mass spectrometry (MS/MS) product ion filtering approach, to investigate cyanopeptolin diversity from 5 Microcystis strains and 4 bloom samples collected from lakes in Ontario and Quebec, Canada. Data processing by DFF was used to search MS/MS data sets for pairs of diagnostic product ions corresponding to cyanopeptolin partial sequences. For example, diagnostic product ions at m/z 150.0912 and 215.1183 identified cyanopeptolins with the NMe-Tyr-Phe-Ahp partial sequence. Forty-eight different cyanopeptolins, including 35 new variants, were detected from studied strains and bloom samples. Different cyanopeptolin profiles were identified from each sample. We detected a new compound, cyanopeptolin 1143, from a bloom and elucidated its planar structure from subsequent targeted MS/MS experiments. Diagnostic fragmentation filtering is a rapid, easy-to-perform postacquisition metabolomics strategy for inferring structural features and prioritizing new compounds for further study and dereplication. More work on cyanopeptolin occurrence and toxicity is needed because their concentrations in freshwater lakes after blooms can be similar to those of microcystins. Environ Toxicol Chem 2021;40:1087-1097. © 2020 SETAC.

Improved methods for biomarker analysis of the big five mycotoxins enables reliable exposure characterization in a population of childbearing age women in Rwanda.

Of the five agriculturally important mycotoxins, AFB1, FB1, DON, ZEA and OTA, a well-characterized biomarker of exposure in blood is only available for aflatoxin. Working with a population of 139 women of childbearing age in Rwanda, we undertook a comprehensive assessment of their dietary mycotoxin exposure. Using high-resolution LC-MS/MS with stable isotope dilution analysis, the albumin-aflatoxin adduct was quantitated in plasma. Similarly, AFM1, AFB1, AFG1, FB1 and B2, OTA, zearalenone, α-zearalenol, deoxynivalenol, deoxynivalenol-15-glucuronide and deoxynivalenol-3-glucuronide were quantitated in urine. AFB1-Lys was detected in plasma from 81% of the women, indicative of exposures 1-2 orders of magnitude above current guidance. Zearalenone and/or α-zearalenol were detected in the urine of 61% of the women, the majority of whom had estimated exposures 2-5 times the PMTDI, with one third more than an order of magnitude above. Urinary deoxynivalenol or the two glucuronide conjugates were found in 77% of the participants. Of these, 60% were below the PMTDI, 28% were twice and 12% were >10x the PMTDI. Fumonisin B1 (30%) and ochratoxin A (71%) were also detected in urine. Exposures observed in these Rwandan women raise serious food safety concerns and highlight the need for authorities to help manage multiple mycotoxins in their diet.

Metabolomics reveals chemical changes in Acer saccharum sap over a maple syrup production season.

Maple syrup, made by boiling the sap of Acer saccharum, is an important agriculture commodity in eastern Canada and New England. Although the collection season is relatively short, a rich progression in the sensory qualities of maple syrup can occur throughout the season. A risk associated with maple syrup production at the end of a season is the development of off-flavors that result in syrup with little to no commercial value. Maple syrup producers in Canada and the USA call this 'buddy syrup'. In this study, sugar maple (Acer saccharum) sap was collected in sequential samples through the harvest season from stands across Ontario. Metabolomics analysis of the sap samples was performed by high-resolution mass spectrometry. This revealed an evolution of the chemical composition, mainly occurring 30 days prior to leaf emergence. The major chemical constituent of maple syrup, sucrose, decreased sharply in late season sap, driven by microbial activity. The alditol mannitol increased in late season sap to concentrations ≥2 mg/mL and is likely an indicator of the start of photosynthesis. Amino acids, notably methionine and asparagine were present in higher amounts in late season sap. Non-targeted analysis revealed a series of related compounds that contained quaternary ammonium moieties including choline, hercynine, trigonelline, glycine betaine and carnitine increased in late season sap. These classes of compounds could act as methyl donors during the heating/evaporation of sap into syrup, affecting taste. Based on descriptions of the nature of buddy syrup and an extensive literature on flavors in foods, the amino acids methionine and asparagine were found as likely precursors to the compounds responsible for buddy syrup.

Metabolomic-guided discovery of cyclic nonribosomal peptides from Xylaria ellisii sp. nov., a leaf and stem endophyte of Vaccinium angustifolium.

Fungal endophytes are sources of novel bioactive compounds but relatively few agriculturally important fruiting plants harboring endophytes have been carefully studied. Previously, we identified a griseofulvin-producing Xylaria species isolated from Vaccinium angustifolium, V. corymbosum, and Pinus strobus. Morphological and genomic analysis determined that it was a new species, described here as Xylaria ellisii. Untargeted high-resolution LC-MS metabolomic analysis of the extracted filtrates and mycelium from 15 blueberry isolates of this endophyte revealed differences in their metabolite profiles. Toxicity screening of the extracts showed that bioactivity was not linked to production of griseofulvin, indicating this species was making additional bioactive compounds. Multivariate statistical analysis of LC-MS data was used to identify key outlier features in the spectra. This allowed potentially new compounds to be targeted for isolation and characterization. This approach resulted in the discovery of eight new proline-containing cyclic nonribosomal peptides, which we have given the trivial names ellisiiamides A-H. Three of these peptides were purified and their structures elucidated by one and two-dimensional nuclear magnetic resonance spectroscopy (1D and 2D NMR) and high-resolution tandem mass spectrometry (HRMS/MS) analysis. The remaining five new compounds were identified and annotated by high-resolution mass spectrometry. Ellisiiamide A demonstrated Gram-negative activity against Escherichia coli BW25113, which is the first reported for this scaffold. Additionally, several known natural products including griseofulvin, dechlorogriseofulvin, epoxy/cytochalasin D, zygosporin E, hirsutatin A, cyclic pentapeptides #1-2 and xylariotide A were also characterized from this species.

Comparing genotype and chemotype of Fusarium graminearum from cereals in Ontario, Canada.

Fusarium graminearum is responsible for production of the mycotoxin deoxynivalenol (DON) on maize and wheat in Ontario, Canada. It has been understood since the early 1980s that in most parts of Canada, the predominant chemotype of F. graminearum is 15ADON, and not the 3ADON chemotype mainly found in Europe and Asia. The discovery of F. graminearum strains that did not produce DON but the structurally related 7-α hydroxy, 15-deacetylcalonectrin (3ANX) and its hydrolysis product 7-α hydroxy, 3,15-dideacetylcalonectrin to (NX) demonstrated that we still have a lot to learn about this well studied but complicated fungus. We conducted a survey of maize and wheat samples from Ontario farms. In the 2015 crop year, we isolated 86 strains and tested a representative subset of 20 using the published genetic probes for assessing genotype. We also developed a targeted LC-MS/MS method for the identification and quantitation of known toxins from this species to determine chemotype. The results showed that 80% of our strains produced some 3ANX in addition to 15ADON and one strain produced 3ANX and no 15ADON. Comparison of chemical data with genotyping revealed that in more than 50% of the cases there was no clear agreement. These data demonstrate the importance of chemical analysis for understanding the toxigenic potential of strains, especially using a LC-MS method that is capable of differentiating 3ADON and 15ADON. For this collection, genotyping of isolates did not produce reliable information on the chemotype. This is the first report of 3ANX toxin production concurrently with 15ADON and suggests that the 3ANX producers in North America likely originated from the 15ADON background.

Mycotoxin Testing Paradigm: Challenges and Opportunities for the Future.

Mycotoxins are one of the great global challenges to agri-food and feed safety. Industry requires fast, reliable, and economical testing methods for the most important regulated mycotoxins to manage this problem. Climate change and changes in agricultural practice are complicating this situation, triggering the movement of some mycotoxins into new regions, which are unprepared for their management. Modern LC-tandem MS (LC-MS/MS) instruments have addressed this analytical challenge, but such instruments are expensive and require highly qualified personnel and dedicated facilities. As a result of these limitations, traditional LC-MS/MS is not amenable for use on farms or at small to midsized processing facilities, such as a grain elevator. To address the need for on-site rapid testing, the mycotoxin community has focused on antibody-based and spectrophotometric approaches. The development of innovative technologies such as miniaturized MS would allow for the acquisition of more information on mixtures of toxins present in a sample at costs comparable to those of the existing rapid methods such as ELISA. The capital costs are higher, but it would reduce per-sample testing costs and time requirements and provide better value for money while maintaining the accuracy and selectivity achieved in a laboratory setting. In this article, we review the available techniques and contrast them in the context of three main criteria: method performance, speed of analysis, and cost. We define the integration of these three parameters as the "mycotoxin testing paradigm."

New 1,3-benzodioxin-4-ones from Synnemapestaloides ericacearum sp. nov., a biosynthetic link to remarkable compounds within the Xylariales.

Surveys of foliar endophytes from the Acadian forest region over the past three decades have identified numerous phylogenetically diverse fungi producing natural products toxic to forest pests and diseases. The life histories of some conifer endophytes can be restricted to plant foliage or may include saprotrophic phases on other plants tissues or even alternate hosts. Considering the potentially broad host preferences of conifer endophytes we explored fungi isolated from understory species and their metabolites as part of an ongoing investigation of fungal biodiversity from the Acadian forest. We report a hitherto unidentified Xylariomycetidae species isolated from symptomatic Labrador tea (Rhododendron groenlandicum) leaves and mountain laurel (Kalmia latifolia) collected in coastal southern New Brunswick, Canada. Morphological and phylogenetic evidence demonstrated the unknown species was a novel Synnemapestaloides (Sporocadaceae) species, described here as Syn. ericacearum. A preliminary screening assay indicated that the culture filtrate extract of the new species was potently antifungal towards the biotrophic pathogen Microbotryum violaceum, warranting an investigation of its natural products. Two natural products possessing a rare 1,3-benzodioxin-4-one scaffold, synnemadoxins A-B (1-2), and their postulated precursor, synnemadiacid A (3), were characterized as new structures and assessed for antimicrobial activity. All isolated compounds elicited in vitro inhibitory antifungal activity towards M. violaceum at 2.3 µg mL-1 and moderate antibiotic activity. Further, the characterization of synnemadoxins A-B provided a perspective on the biosynthesis of some related 1,3-benzodioxin-4-ones produced by other fungi within the Xylariales.

The Mycotox Charter: Increasing Awareness of, and Concerted Action for, Minimizing Mycotoxin Exposure Worldwide.

Mycotoxins are major food contaminants affecting global food security, especially in low and middle-income countries. The European Union (EU) funded project, MycoKey, focuses on “Integrated and innovative key actions for mycotoxin management in the food and feed chains” and the right to safe food through mycotoxin management strategies and regulation, which are fundamental to minimizing the unequal access to safe and sufficient food worldwide. As part of the MycoKey project, a Mycotoxin Charter (charter.mycokey.eu) was launched to share the need for global harmonization of mycotoxin legislation and policies and to minimize human and animal exposure worldwide, with particular attention to less developed countries that lack effective legislation. This document is in response to a demand that has built through previous European Framework Projects—MycoGlobe and MycoRed—in the previous decade to control and reduce mycotoxin contamination worldwide. All suppliers, participants and beneficiaries of the food supply chain, for example, farmers, consumers, stakeholders, researchers, members of civil society and government and so forth, are invited to sign this charter and to support this initiative.

Aflatoxin exposure in Nigerian children with severe acute malnutrition.

Aflatoxin exposure is an important public health concern in sub-Saharan Africa as well as parts of Latin America and Asia. In addition to hepatocellular carcinoma, chronic aflatoxin exposure is believed to play a role in childhood growth impairment. The most reliable biomarker of chronic aflatoxin exposure is the aflatoxin-albumin adduct, as measured by ELISA or isotope dilution mass spectrometry (IDMS). In this report, we have used high resolution LC-MS/MS with IDMS to quantitate AFB1-lysine in an extremely vulnerable population of Nigerian children suffering from severe acute malnutrition. To increase the sensitivity and reliability of the analyses, a labelled AFB1-13C615N2-lysine internal standard was synthesized. AFB1-lysine concentrations in this population ranged between 0.2 and 59.2 pg/mg albumin, with a median value of 2.6 pg/mg albumin. AFB1-lysine concentrations were significantly higher in stunted children (median = 4.6 pg/mg) compared to non-stunted (1.2 pg/mg), as well as in children with severe acute malnutrition (4.3 pg/mg) compared to controls (0.8 pg/mg). The median concentrations were also higher in children with kwashiorkor (6.3 pg/mg) compared to those suffering from marasmus (0.9 pg/mg). This is the first report of the use of high-resolution mass spectrometry to quantitate AFB1-lysine in humans.

Occurrence of Penicillium verrucosum, ochratoxin A, ochratoxin B and citrinin in on-farm stored winter wheat from the Canadian Great Lakes Region.

The occurrence of P. verrucosum and ochratoxin A (OTA) were surveyed for 3 and 4 years, respectively. A total of 250 samples was collected from an average of 30 farms during the 2011, 2012, 2013 and 2014 winter seasons. Most storage bins surveyed were typically 11 m high round bins made of corrugated, galvanized steel, with flat-bottoms and conical roofs. Samples of clumped grain contained the most P. verrucosum (p<0.05, n = 10) followed by samples taken from the first load (n = 24, mean = 147±87 CFU/g) and last load (n = 17, mean = 101±77 CFU/g). Five grain samples (2.2%) tested positive for OTA, citrinin and OTB at concentrations of 14.7±7.9, 4.9±1.9 and 1.2±0.7 ng/g, with only three samples exceeding 5 ng/g. Grain samples positive for OTA were related to moisture resulting from either condensation or migrating moist warm air in the bin or areas where precipitation including snow entered the bin. Bins containing grain and clumps contaminated with OTA were studied in detail. A number of statistically-significant risk factors for OTA contamination were identified. These included 1) grain clumps accumulated around or directly under manhole openings, 2) debris and residue of old grain or grain clumps collected from the bin walls or left on storage floor and augers and 3) grain clumps accumulated around side doors. Even when grain enters storage below the 14.5% threshold of moisture, condensation and moisture migration occurs in hotspots in modern corrugated steel storage bins. Hot spots of OTA contamination were most often in areas affected by moisture migration due to inadequate aeration and exposure to moisture from precipitation or condensation. Further, we found that the nature of the condensation affects the nature and distribution of small and isolated areas with high incidence of toxin contamination and/or P. verrucosum prevalence in the grain bins examined.