COVID-19 pandemic responses of Canada and United States in first 6 months: A comparative analysis.

INTRODUCTION: Canada and the United States have distinct health care and social policies, and it is important to see how they had been responding to the ongoing COVID-19 pandemic. METHODS: The study period was limited to the first 6 months of the pandemic and aimed to explore the responses by public health authorities, media, general population, and law makers during the initial phase of pandemic. RESULTS: Social disparity, underfunded pandemic preparation, and the initial failure to act appropriately have resulted in the rapid spread of infection in both countries. In the United States, prevailing social inequalities and racism, inaccessible health care, higher rates of preexisting medical conditions and disputed political leadership have further deteriorated the situation and enhanced public suffering, particularly for the black and Indigenous communities. In Canada, its poorly regulated services of long-term care facilities, initial restriction of testing and lack of access to epidemiological data have helped spread the infection and increased casualties in vulnerable populations. CONCLUSION: Analysis of the pandemic responses of the United States and Canada has revealed how existing social disparity, underfunded pandemic preparation, and the initial failure to act appropriately have resulted in the rapid spread of infection.

Effects of low exposure to traffic related air pollution on childhood asthma onset by age 10 years.

Although NO2, a major traffic related air pollutant, has been associated with onset of childhood asthma, young children may be more susceptible to traffic related air pollution exposure compared to other individuals. We linked data from National Longitudinal Survey of Children and Youths Cycle 1-5 (1994-2003) and the National Air Pollution Surveillance Program to determine the association between NO2 exposure and either early or late onset childhood asthma phenotypes. Children diagnosed with asthma from age 0-3 were defined as having early onset asthma. Children diagnosed with asthma from age 4-9 were defined as having late onset asthma. Mean NO2 exposure for each quartile was 6.31 ppb, 9.45 ppb, 11.83 ppb, and 17.9 ppb. Higher levels of NO2 exposure were more strongly associated with early childhood asthma (Quartile 3 OR: 2.11, 95% CI: 1.29, 3.44, Quartile 4 OR: 2.16, 95% CI: 1.27, 3.68) compared to the lowest level of NO2 exposure (Quartile 1). No such association was observed with risk of late childhood asthma onset. Asthma susceptibility to NO2 exposure may vary with the childhood developmental stage, and young children may be susceptible to NO2 exposure at levels well below national and international guidelines. Our study emphasizes the importance of considering the timing of childhood asthma onset in future studies and confirms the increased risk of early onset of childhood asthma associated even with relatively low NO2 exposure levels.

Risk Factors for Fatal Middle East Respiratory Syndrome Coronavirus Infections in Saudi Arabia: Analysis of the WHO Line List, 2013-2018.

Objectives. To explore complex associations among demographic factors, risk factors, health care, and fatality rates of Middle East respiratory syndrome coronavirus (MERS-CoV) in the Kingdom of Saudi Arabia.Methods. We based this study on analysis of a publicly accessible line listing of 1256 MERS-CoV cases (2013 to October 2018) available on the World Health Organization's Web site. For analyses of demographic factors (e.g., age, gender), access to health care, promptness of laboratory services, risk factors (comorbidity, exposure to camels and persons with MERS-CoV), occupation (health care), and outcome (fatality), we used descriptive statistics, risk ratio (RR), and the Pearson χ2 test.Results. Presence of comorbidity (RR = 3; 95% confidence interval [CI] = 2.2, 3.9), being male (RR = 1.6; 95% CI = 1.2, 2.1), exposure to dromedary camels (RR = 1.6; 95% CI = 1.3, 2.3), and consumption of camel milk (RR = 1.5; 95% CI = 0.9, 1.7) can significantly increase risk for fatality. Health care workers have significantly lower fatality (P < .001) than the rest of the persons with MERS-CoV.Conclusions. Policies that promote health awareness for the high-risk population and their prompt seeking of health care should be considered. Publicly accessible line lists of infectious diseases such as MERS-CoV can be valuable sources for epidemiological analysis.

Exploring relevance, public perceptions, and business models for establishment of private well water quality monitoring service.

Existing public policies mostly focus on public water systems, leaving aside the quality issues regarding private wells in small and rural locations. Establishment of affordable and accessible water quality monitoring services may ensure acceptable levels of all the parameters. This paper aims to explore (a) health risk because of chemical contaminants of private wells, (b) population perspective on well water quality and monitoring, and (c) to create a business model of a centralized water quality monitoring service. The results show potential problems with toxic levels of arsenic, barium, cadmium, chromium, lead, mercury, and selenium. About 5% of the province's population is at risk for potential exposure to contaminated private well water. The survey reinforces that the successful implementation of water testing laboratories for private wells is a shared responsibility between well owners and the government organizations, and almost three-fourths respondents were willing to share the cost up to certain limit. A business model including financial projections for a centralized water testing laboratory is presented. Drinking of unmonitored private well water is putting population health at risk. Either strong regulation with mandatory water testing or voluntary water testing with adequate government subsidy can ensure sustainable function of a centralized water testing laboratory.

Environmental impact assessment of uranium exploration and development on indigenous land in Labrador (Canada): a community-driven initiative.

There is hardly any study on environmental impacts of uranium exploration and mining development prior to actual mining activities. Rather, the majority of the literature addresses the environmental impacts of either ongoing or decommissioned mines. The objective of the study was to measure the possible radioactive contamination (total uranium and lead) in the local ecosystem surrounding an abandoned uranium development site on indigenous land in Labrador (Canada). Water (brook and ponds), soil/sediments (brook and ponds), plants (growing along the brook and pond shores), and local fish (trout) and clams from bays were collected from mine development site, downstream, and control sites. Uranium and lead mobilization in the local environment appears to be slightly enhanced near the proposed mining site, but rapidly drops downstream. Developing a low-cost, community-based environmental health monitoring tool is an ideal strategy for generating baseline information and further follow-up.

Association between perceptions of public drinking water quality and actual drinking water quality: A community-based exploratory study in Newfoundland (Canada).

Studying public perception on drinking water quality is crucial for managing of water resources, generation of water quality standards, and surveillance of the drinking-water quality. However, in policy discourse, the reliability of public perception concerning drinking water quality and associated health risks is questionable. Does the public perception of water quality equate with the actual water quality? We investigated public perceptions of water quality and the perceived health risks and associated with the actual quality of public water supplies in the same communities. The study was conducted in 45 communities of Newfoundland (Canada) in 2012. First, a telephone survey of 100 households was conducted to examine public perceptions of drinking water quality of their respective public sources. Then we extracted public water quality reports of the same communities (1988-2011) from the provincial government's water resources portal. These reports contained the analysis of 2091 water samples, including levels of Disinfection By-Products (DBPs), nutrients, metals, ions and physical parameters. The reports showed that colour, manganese, total dissolved solids, iron, turbidity, and DBPs were the major detected parameters in the public water. However, the majority of the respondents (>56%) were either completely satisfied or very satisfied with the quality of drinking water. Older, higher educated and high-income group respondents were more satisfied with water quality than the younger, less educated and low-income group respondents. The study showed that there was no association with public satisfaction level and actual water quality of the respective communities. Even, in the communities, supplied by the same water system, the respondents had differences in opinion. Despite the effort by the provincial government to make the water-test results available on its website for years, the study showed existing disconnectedness between public perception of drinking water quality and actual quality. We had little scope to explore the possible explanations, and hence further studies are required to verify the age, gender educational status and income differential about the satisfaction of public service like water supply.

Water insecurity in Canadian Indigenous communities: some inconvenient truths.

INTRODUCTION: Canada has the second highest per capita water consumption in the world. However, little is known about complex socio-economic and cultural dynamics of water insecurities in Indigenous communities and the multiple health consequences. Most studies have concentrated on a simplified interpretation of accessibility, availability and quality issues, including some common water-borne infections as the only health outcomes. Thus, several government initiatives on potable water supply, particularly for remotely located communities, have failed to sustain and promote a healthy lifestyle. The objective was to explore the water insecurity, coping strategies and associated health risks in a small and isolated sub-Arctic Indigenous (Inuit) community in Canada. METHODS: The study was based on a community-based survey (2013) in one of the most remote Inuit communities of Labrador. In-depth, open-ended key informant (KI) interviews (community leader (1), woman (1), nurse (1), teacher (1), and elder (1)) and focus group discussions (FGDs) were conducted with community leaders (5), community members (25), women (5), and high school students (8). Convenience sampling was followed in selection of the subjects for FGDs and approached some KIs. All the water sources (five in April and seven in October) were visited and tested for their physical, chemical and microbiological parameters. The FGDs and KI interviews were audio recorded and transcribed. In the analysis, the data (qualitative and quantitative) were broadly categorized into (a) water sources, access and quality, (b) coping, (c) health risks and (d) challenges to run a public water system. RESULTS: The community did not have any piped water supply. Their regular sources of water consisted of several unmonitored local streams, brooks, and ponds. The public water system was not affordable to the majority of community members who solely depended on government aid. Animal fecal contamination (in natural sources such as streams, brooks, and ponds) and the presence of disinfection by-products (in the public water system) were the major quality issues. Gastro-intestinal infections were the most common disease in the community. Per capita water consumption was less than one-third of the Canadian national average (274 L/day/person), severely compromising personal hygiene and water intake. High-sugar-content beverages were the most common alternative to lack of accessible and affordable potable water, particularly for children. Mental stress due to water insecurity and chronic back and shoulder injuries due to carrying heavy water buckets every day were the commonly encountered adverse health outcomes. CONCLUSIONS: Water insecurity has put the community at risk of multiple serious adverse health outcomes. The scenario is not unique in Canada. There are many remote Indigenous communities facing similar kinds of water insecurity.

Contamination of aquatic ecosystems by persistent organic pollutants (POPs) originating from landfills in Canada and the United States: A rapid scoping review.

Persistent organic pollutants (POPs) are organic chemical substances that threaten human health and the planet's ecosystems due to their toxicity and their ability to remain intact for a long time, wide distribution throughout the environment, and accumulation and magnification in living organisms through the food chain. Discarded products from landfills and dumpsites are potential sources of POPs due to their persistence for several decades and constant release to surrounding environment. POPs in aquatic systems signal input predominantly from landfills, wastewater treatment plants, sewage, and urban runoff, suggesting a research gap to guide policies to address these unabated releases. This scoping review aims to rapidly identify the key concepts underpinning the containment, translation, and migration of POPs in Canadian and US landfill leachate. The review targeted multidisciplinary perspectives on the topic and spanned forensic biology, environmental sciences, chemistry, and geology. Contaminated municipal solid waste (MSW) landfill characteristics, as reported by government agencies in Canada and the US, were synthesized and harmonized to illustrate the geographical scope of MSW landfills releasing POPs into the surrounding environment. The knowledge and data gaps summarized in this study highlight the need to address the inadvertent release of POPs from Canadian and US landfills, particularly in consideration of dated and degrading landfill infrastructure, the proximity of marginalized people, and the implications of climate change on the countries' more vulnerable landscapes. This review is applicable to the development of future studies that aim to guide environmental protective policies.

Ethics guidelines for environmental epidemiologists: 2023 revision.

Recognition of the importance to environmental epidemiology of ethical and philosophical deliberation led, in 1996, to the establishment of Ethics Guidelines for the profession. In 1999, these guidelines were adopted by the International Society for Environmental Epidemiology. The guidelines were revised in 2012 and again in 2023 to ensure continued relevance to the major issues facing the field. Comprising normative standards of professional conduct, the guidelines are structured into four subsections: (1) obligations to individuals and communities who participate in research; (2) obligations to society; (3) obligations regarding funders/sponsors and employers; and (4) obligations to colleagues. Through the 2023 revision of the Ethics Guidelines, the International Society for Environmental Epidemiology seeks to ensure the highest possible standards of transparency and accountability for the ethical conduct of environmental epidemiologists engaged in research and public health practice.

Occupational noise exposure at sea: A socio-legal study on fish harvesters' perceptions in Newfoundland and Labrador, Canada.

Introduction: Noise is a significant health hazard for fish harvesters. Chronic exposure to hazardous noise levels of 85 dB (A) for an 8-h work shift can have adverse health impacts, including both auditory and non-auditory health problems such as noise-induced hearing loss, stress, hypertension, sleeping disorders, and impaired cognitive performance. Methods: A review of legislation and policies governing workplace noise exposure, as well as qualitative, semi-structured interviews, were conducted to assess how fish harvesters in Newfoundland and Labrador (NL) manage onboard occupational noise exposure and perceive noise-induced health problems, as well as the barriers and challenges associated with preventing and controlling noise exposure. Results: The legal review shows no compulsory noise preventive measure at the fishing vessel design stage in Canada. Limited implementation of Occupational Health and Safety (OHS) regulations to control and prevent onboard noise by employers in Newfoundland and Labrador. Fishers reported that their workplace is noisy. Over time, fish harvesters adapted to the environment and learned to tolerate loud noise, displaying fatalistic behavior. Fish harvesters reported avoiding using hearing protection onboard due to navigation safety concerns. Fishers reported hearing loss as well as other non-auditory health problems. Inadequate noise control measures adopted by employers, a limited supply of hearing protection onboard, and a lack of regular hearing testing, training, and education were identified as the main barriers to preventing and controlling noise exposure. Conclusion: Proper implementation of NL OHS regulations and the development of hearing conservation initiatives by employers are necessary. All stakeholders, including the federal and provincial governments, WorkplaceNL, and not-for-profit fishing organizations in the province, are strongly recommended to initiate training and education campaigns to help fish harvesters understand noise exposure and adopt preventive measures.

Dietary exposure to thyroid disrupting chemicals: a community-based study in Canada.

The marine ecosystem around the Island of Newfoundland is contaminated by thyroid disrupting chemicals (TDCs). Coastal inhabitants may be exposed to TDCs through consumption of contaminated local seafood products and affecting thyroid functions. The aim of this study was to explore: (1) consumption frequency of local seafood products consumed by rural residents, (2) thyroid hormones (THs) and TDCs concentrations in residents, (3) relationships between local seafood consumption, TDC concentrations, and THs. Participants (n = 80) were recruited from two rural Newfoundland communities. Seafood consumption was measured through a validated seafood consumption questionnaire. Blood samples were collected from all participants and tested for THs (thyroid stimulating hormone, free thyroxine, free triiodothyronine) and TDCs, including polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), and dichlorodiphenyldichloroethylene (p,p'-DDE). Cod was the most frequently consumed local species, but there was a wide range of other local species consumed. Older participants (>50 years) had greater plasma concentrations of PBB-153, PCBs and p,p'-DDE, and males had higher concentrations of all TDCs than females. The consumption frequency of local cod was found to be positively associated with several PCB congeners, p,p'-DDE and ∑14TDCs. There was no significant relationship between TDCs and THs in either simple or multivariate linear regression analyses.

Emerging health risks associated with modern agriculture practices: a comprehensive study in India.

In order to enhance food production, India has adopted modern agriculture practices and achieved noteworthy success. This achievement was essentially the result of a paradigm shift in agriculture that included high inputs of agrochemicals, water, and widespread practice of monoculture, as well as bureaucratic changes that promoted these changes. There are very few comprehensive analyses of potential adverse health outcomes that may be related to these changes. The objective of this study is to identify health risks associated with modern agricultural practices in the southern Indian state of Karnataka. This study aims to compare high-input and low-input agricultural practices and the consequences for health of people in these communities. The fieldwork was conducted from May to August, 2009 and included a survey carried out in six villages. Data were collected by in-depth personal interviews among 240 households and key informants, field observations, laboratory analyses, and data from secondary sources. The study identified four major visible impacts: occupational hazards, vector borne diseases, changing nutritional status, and inequity in development. In the high-input area, mechanization has resulted in more occurrences of serious accidents and injuries. Ecological changes due to rice cultivation in this area have further augmented mosquito breeding, and there has been a surge in the incidence of Japanese encephalitis and malaria. The traditional coarse cereals (complex carbohydrates, high protein) have been replaced by mill-polished rice (simple carbohydrate, low protein). The prevalence of overweight (BMI>25) has emerged as a new public health challenge, and this is most evident in large-landholding households, especially in the high-input agriculture areas. In all agro-ecological areas, it was observed that women faced a greater risk of both extremes of under-nutrition and being overweight. Output-driven and market-oriented modern agricultural practices have changed the ecology and disease pattern in this area in India, and our survey indicated significant health effects associated with these changes. There is a need for more extensive epidemiological studies in order to know the full impact on diseases and to understand the complex causal relationships.

Middle East respiratory syndrome coronavirus (MERS-CoV) infection: Analyses of risk factors and literature review of knowledge, attitude and practices.

The study aimed to explore the risk factors for MERS-CoV infection and systematic review of knowledge, attitudes and practices (KAP) with regard to MERS-CoV among the health care workers (HCWs) and the general population. The World Health Organization's MERS-CoV line list (January 2013-January 2020) of the Kingdom of Saudi Arabia (KSA) was analysed. A Poisson regression model was used to calculate the univariate relative risk of outcomes to each potential risk factor, p-values and 95% confidence intervals. An electronic literature search was conducted to assess knowledge, attitudes and practices of the HCWs and general population of the KSA, with regards to transmission of the infection, risk factors and preventative measures. The line list analysis shows that age, gender, comorbidity, exposure to camels and camel milk consumption were associated with an increased risk of fatality; however, year-wise analysis did not show any decline. Over the years, the mean durations between the symptom onset and hospitalization; the hospitalization and laboratory confirmation have reduced. The review of literature shows that the health care workers and the general population had inadequate knowledge about MERS-CoV, lacked motivation and were disconnected from the health authorities. The WHO line list provides information on risk factors for MERS-CoV, KAP analysis helps to know the potential underlying factors. The literature review shows that continuous education for HCWs and increasing public awareness can help effectively manage future MERS-CoV.

A Study of the Effectiveness of Workplace Health and Safety Programmes in a University Setting in Canada.

Introduction: Nearly a quarter-million people work in universities in Canada, making it one of the fastest-growing sectors. Although each university provides occupational health and safety services and training programmes to their employees, there have been no studies conducted on the impact of such programmes on employees' knowledge, attitude and behaviour. The aim of this study was to evaluate the effectiveness of dissemination of information of workplace health and safety programmes to workers at a Canadian university. Methods: The study compared two cross-sectional online surveys of employees of a Canadian university regarding workplace health and safety with a previously conducted cross-sectional study and thematic analysis of key informant interviews to address the issues raised in the surveys. Results: Participation in health and safety presentations could enhance understanding and practices of safety. Age, employment status and duration of employment were associated with the levels of knowledge, attitudes and behaviour of employees and graduate students. The key informant interviews highlighted some new initiatives such as the establishment of workplace health and safety committees in all university buildings; the development of a safety app and health and safety management system; routine annual inspections of all university building offices and laboratories; new orientation for undergraduate students where general safety rules are described. Discussion: University should have regular presentations on the available health and safety programmes and should increase the number of safety training programmes and keep track of the employees that have not received any training, particularly for those working in hazardous environments.

Polybrominated Diphenyl Ethers (PBDEs) in Marine Fish and Dietary Exposure in Newfoundland.

Presence of PBDEs tested in 127 liver samples from Atlantic Cod (Gadus morhua) and Turbot (Scophthalmus Maximus) and 80 adult participants from two rural Newfoundland communities. Seafood consumption was measured through a validated seafood consumption questionnaire. PBDEs (-28, -47, -99, -156, and -209) were found in all fish liver samples, and PBB-153 and PBDEs-28, -47, -99, -100, -153 were identified as the most prominent congeners from the participants' serum samples. Cod was the most frequently consumed species in the seafood consumption survey. PBB-153 was higher amongst older (> 50 years age) participants (p < 0.0001), however, no PBDE congeners were significantly different by age. PBB-153 (p = 0.001), PBDE-153 (p = 0.006), and 5PBDE (p = 0.008) levels were significantly higher in males. The study shows that the marine ecosystem around Newfoundland has been contaminated by PBDEs, and that rural coastal residents are potentially exposed to these contaminants through local seafood consumption.

Social determinants of multidrug-resistant tuberculosis: A scoping review and research gaps.

Tuberculosis is a prime example of a social disease that requires social, economic and environmental interventions. However, research on social determinants of Multidrug-Resistant (MDR-TB) is limited. The five-stage scoping review showed the most common association of MDR-TB with multidimensional poverty (income, nutrition, education and social support) both as a contributing factor and a consequence of it. The review also found that physical environment (inadequate housing, overcrowding, poor physical environment, and smoking), health care needs, cultural determinants (race, ethnicity and gender), comorbidities had a strong influence on the development and transmission of MDR-TB. Since, epidemiology and care for MDR-TB are greatly influenced by socioeconomic factors, social, environmental and economic actions are needed in addition to the implementation of novel diagnostic techniques and treatments.

Occupational noise exposure and health impacts among fish harvesters: a systematic review.

BACKGROUND: Occupational noise exposure has been identified as a significant risk factor for fish harvesters. Chronic noise exposure causes hearing and other health problems and undermines the quality of life and well-being. This review paper aims to highlight noise-related auditory and non-auditory health effects among fish harvesters. MATERIALS AND METHODS: A systematic literature search approach was adopted using the following databases: PubMed, Embase, SCOPUS, Web of Science, Google Scholar, and by exploring grey literature. The literature search was conducted in 2020 (between October 15 and November 30). Relevant articles were explored by reviewing title, keywords, and abstract based on the inclusion and exclusion criteria. The full-text critical review of selected papers was made and finalized the most relevant studies. RESULTS: Initial 1,281 records were identified, exploring various databases and additional sources using relevant keywords. Duplicate articles were removed and retrieved 746 articles. After that, a screening of 746 research papers was done based on the selection criteria and finalised 28 articles for full-text review. Finally, articles were filtered based on the study's aim and extracted 17 papers for the final review. CONCLUSIONS: Noise-induced hearing loss was considered a significant health risk to fish harvesters across the studies, affecting physical and emotional well-being. The prevalence of hearing loss was observed from 6% to 80%. Other health problems, such as headache, dizziness, annoyance, stress, fatigue, elevated blood pressure, sleep disturbances, and impaired cognitive performance, were also reported. Further research is needed to validate the non-auditory health effects among fish harvesters.

Potential human health risks due to environmental exposure to nano- and microplastics and knowledge gaps: A scoping review.

Microplastics are an emerging global environmental contaminant that are affecting multiple spheres. Despite their ubiquity in all spheres of life and ecology, little is known about the health effects of microplastics exposure to humans. This scoping review explores the existing evidence on the potential human health effects of microplastics and subsequent knowledge gaps. An electronic search of published articles in PubMed, Scopus, EMBASE, Cochrane databases, and Google Scholar was conducted using a combination of subject headings and keywords relating to microplastics and human health effects. The initial search resulted in 17,043 published articles and grey literature documents. After a full review of published articles and their references, 129 publications were identified for further detailed review. These articles indicate that human exposure to microplastics can occur through ingestion, inhalation, and dermal contact due to their presence in food, water, air, and consumer products. Microplastics exposure can cause toxicity through oxidative stress, inflammatory lesions, and increased uptake or translocation. Several studies have demonstrated the potentiality of metabolic disturbances, neurotoxicity, and increased cancer risk in humans. Moreover, microplastics have been found to release their constituent compounds as well as those that are adsorbed onto their surface. Further research is needed to quantify the effects of microplastics on human health and their pathogenesis.

Molecular diversity of Mycobacterium tuberculosis complex in Sikkim, India and prediction of dominant spoligotypes using artificial intelligence.

In India, tuberculosis is an enormous public health problem. This study provides the first description of molecular diversity of the Mycobacterium tuberculosis complex (MTBC) from Sikkim, India. A total of 399 Acid Fast Bacilli sputum positive samples were cultured on Lowenstein-Jensen media and genetic characterisation was done by spoligotyping and 24-loci MIRU-VNTR typing. Spoligotyping revealed the occurrence of 58 different spoligotypes. Beijing spoligotype was the most dominant type constituting 62.41% of the total isolates and was associated with Multiple Drug Resistance. Minimum Spanning tree analysis of 249 Beijing strains based on 24-loci MIRU-VNTR analysis identified 12 clonal complexes (Single Locus Variants). The principal component analysis was used to visualise possible grouping of MTBC isolates from Sikkim belonging to major spoligotypes using 24-MIRU VNTR profiles. Artificial intelligence-based machine learning (ML) methods such as Random Forests (RF), Support Vector Machines (SVM) and Artificial Neural Networks (ANN) were used to predict dominant spoligotypes of MTBC using MIRU-VNTR data. K-fold cross-validation and validation using unseen testing data set revealed high accuracy of ANN, RF, and SVM for predicting Beijing, CAS1_Delhi, and T1 Spoligotypes (93-99%). However, prediction using the external new validation data set revealed that the RF model was more accurate than SVM and ANN.

Evaluating the use of synchrotron X-ray spectroscopy in investigating brominated flame retardants in indoor dust.

Brominated flame retardants (BFRs) are commonly used in consumer products and they shed off these products and eventually build up in household dust. Polybrominated diphenyl ethers (PBDEs), in particular, are known endocrine-disrupting chemicals affecting various hormone syntheses. Portable X-ray fluorescence spectroscopy (XRF) is the most common non-destructive method in identifying BFRs in environmental samples. However, the method is insensitive to bromine speciation. Synchrotron-based XRF has been shown to have very low detection limits (< 1 µg/g) that is suitable for detecting BFRs and can be combined with X-ray absorption near-edge spectroscopy (XANES) to identify the bromine species present in the household dust. Twenty indoor dust samples were collected from rural homes in Newfoundland (Canada) to assess the use of synchrotron-based techniques to identify BFRs. Synchrotron-based XRF analysis identified bromine in all the samples, with concentrations ranging from 2-19 µg/g. XANES analysis identified organic-based bromine species in several samples that are likely BFRs based on the spectral line shape. The accuracy of using XANES to identify BFRs is highly dependent on the source and size of the dust samples. Therefore, for future research, it is important to take into account the sources of dust sample and to focus on fine dust particles.