Developing a reporting item checklist for studies of HIV drug resistance prevalence or incidence: a mixed methods study.

BACKGROUND: Adequate surveillance of HIV drug resistance prevalence is challenged by heterogenous and inadequate data reporting. To address this issue, we recently published reporting guidance documentation for studies of HIV drug resistance prevalence and incidence. OBJECTIVES: In this study, we describe the methods used to develop this reporting guidance. DESIGN: We used a mixed-methods sequential explanatory design involving authors and users of studies of HIV drug resistance prevalence. In the quantitative phase, we conducted a cross-sectional electronic survey (n=51). Survey participants rated various reporting items on whether they are essential to report. Validity ratios were computed to determine the items to discuss in the qualitative phase. In the qualitative phase, two focus group discussions (n=9 in total) discussed this draft item checklist, providing a justification and examples for each item. We conducted a descriptive qualitative analysis of the group discussions to identify emergent themes regarding the qualities of an essential reporting item. RESULTS: We identified 38 potential reporting items that better characterise the study participants, improve the interpretability of study results and clarify the methods used for HIV resistance testing. These items were synthesised to create the reporting item checklist. Qualitative insights formed the basis of the explanation, elaboration, and rationale components of the guidance document. CONCLUSIONS: We generated a list of reporting items for studies on the incidence or prevalence of HIV drug resistance along with an explanation of why researchers believe these items are important. Mixed methods allowed for the simultaneous generation and integration of the item list and qualitative insights. The integrated findings were then further developed to become the subsequently published reporting guidance.

Individuals' Values and Preferences Regarding Medical Cannabis for Chronic Pain: A Descriptive Qualitative Study.

Background: Cannabis for medical purposes has been legal in Canada since 2001; however, physicians receive no formal training in this modality, and clinical use of cannabis remains controversial. This study aims to explore the values and preferences of people living with chronic pain (PLwCP) in using medical cannabis for chronic pain to inform guideline development and shared decision-making in clinical practice. Methods: We conducted a descriptive qualitative study using in-depth interviews with PLwCP. Using a deductive/inductive approach, we developed concepts and themes related to values and preferences of PLwCP on their use (or avoidance) of medical cannabis for chronic pain. Results: We interviewed 52 PLwCP, including current medical cannabis users (40), previous users (10) and non-users (2). Most PLwCP who used cannabis therapeutically reported the need for experimentation to determine what cannabis products, routes, and doses worked for them. Perceived benefits of medical cannabis among current users included relief from pain, better sleep, and improved mental health. Reasons for discontinuing use of medical cannabis included lack of improvement in pain or sleep or undesirable side effects. Cannabidiol (CBD) dominant products were reported to result in minimal adverse effects (eg, physical or mental impairment) compared to tetrahydrocannabinol (THC) dominant products. Perceived barriers or facilitators to use included social acceptability, availability or access, cost, and attitudes and knowledge among healthcare providers. Participants noted different routes of cannabis use including oral routes that provided longer-lasting pain relief with a slower onset and inhaled routes with a more rapid onset with shorter-lived effects. Conclusion: Participants' decisions to use medical cannabis for chronic pain were varied, which suggests these decisions are likely to be sensitive to individuals' values and preferences. There is a call for further research and information-sharing to help PLwCP understand the complexities of cannabis use for medical purposes, including ideal dosing and timing.

Burnout among public health workers in Canada: a cross-sectional study.

BACKGROUND: This study presents the prevalence of burnout among the Canadian public health workforce after three years of the COVID-19 pandemic and its association with work-related factors. METHODS: Data were collected using an online survey distributed through Canadian public health associations and professional networks between November 2022 and January 2023. Burnout was measured using a modified version of the Oldenburg Burnout Inventory (OLBI). Logistic regressions were used to model the relationship between burnout and work-related factors including years of work experience, redeployment to pandemic response, workplace safety and supports, and harassment. Burnout and the intention to leave or retire as a result of the COVID-19 pandemic was explored using multinomial logistic regressions. RESULTS: In 2,079 participants who completed the OLBI, the prevalence of burnout was 78.7%. Additionally, 49.1% of participants reported being harassed because of their work during the pandemic. Burnout was positively associated with years of work experience, redeployment to the pandemic response, being harassed during the pandemic, feeling unsafe in the workplace and not being offered workplace supports. Furthermore, burnout was associated with greater odds of intending to leave public health or retire earlier than anticipated. CONCLUSION: The high levels of burnout among our large sample of Canadian public health workers and its association with work-related factors suggest that public health organizations should consider interventions that mitigate burnout and promote recovery.

Motivational interviewing to promote healthy behaviors for obesity prevention in young adults (MOTIVATE): a pilot randomized controlled trial protocol.

BACKGROUND: Obesity is a chronic disease and is an established risk factor for other chronic diseases and mortality. Young adulthood is a period when people may be highly amenable to healthy behavior change, develop lifelong healthy behaviors, and when primary prevention of obesity may be feasible. Interventions in early adulthood have the potential for primary or primordial prevention (i.e., preventing risk factors before disease onset). The primary objective of this study is to determine the feasibility of a 6-month behavioral and educational intervention to promote healthy behaviors for obesity prevention among young adults. METHODS: This is the study protocol for a pilot randomized controlled trial. Young adults (age 18-29) attending McMaster University, Hamilton, Canada, will be recruited and randomized to either the intervention or control. The intervention will include individual motivational interviewing sessions (online or in-person) with a trained interviewer plus educational materials (based on Canada's food guide and physical activity recommendations). The control group will receive educational materials only. The primary feasibility outcomes that will be evaluated as part of this pilot study include enrollment, retention (≥ 80%), data completion (≥ 80% of weights measured, and surveys completed), and participant satisfaction. Secondary clinical outcomes will include body mass index (BMI) change from baseline to 6 months, physical activity, nutrition risk, health-related quality of life mental health, and economic outcomes. Outcomes will be measured remotely using activity trackers, and online questionnaires at baseline and every 2 months. Risk stratification will be applied at baseline to identify participants at high risk of obesity (e.g., due to family or personal history). Exit questionnaires will collect data on how participants felt about the study and cost analysis will be conducted. DISCUSSION: Our pilot randomized controlled trial will evaluate the feasibility of an obesity prevention intervention in early adulthood and will inform future larger studies for obesity prevention. The results of this study have the potential to directly contribute to the primary prevention of several types of cancer by testing an intervention that could be scalable to public health, post-secondary education, or primary care settings. TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT05264740 . Registered on March 3, 2022.

Facility-Based Maternal Quality of Care Frameworks: A Systematic Review and Best Fit Framework Analysis.

OBJECTIVES: The World Health Organization has adopted two main strategies to improve the quality of maternal health: increasing the number of deliveries by skilled birth attendants and increasing access to emergency obstetric care. Despite increased access to care, there continue to be high rates of maternal morbidity and mortality in part due to quality of care. This study aims to identify and summarize existing frameworks for measuring quality of maternal care at a facility-level. METHODS: PubMed, Health Systems Evidence, Embase, Global Health, OVID Healthstar, OVID Medline, PsycINFO, and Web of Science were searched for frameworks, tools, theories, or components of frameworks relevant to maternal quality of care in facility-level settings. Title/abstract and full-text screening were completed by two independent reviewers and conflicts resolved through consensus or a third reviewer. RESULTS: An initial search resulted in 3182 studies. Fifty-four studies were included in the qualitative analysis. A best fit framework analysis was done using the updated Hulton framework as the conceptual framework. A facility-based maternal quality of care framework is proposed including the following components, separated into provision and experience of care: (1) human resources; (2) infrastructure; (3) equipment, supplies and medicine; (4) evidence and information; (5) referral and networks of care; (6) cultural competence; (7) clinical practice; (8) financing; (9) leadership and governance; (10) cognition; and 11) respect, dignity, equity, and emotional support.

Despite increased institutional access to care, there continue to be high rates of maternal morbidity and mortality in some low- and middle-income countries. This is in part due to the quality of maternal care once care has been accessed. Several frameworks have been proposed for understanding the complexities surrounding quality of care in maternal health but there has not been a single framework consistently used in the literature for facility-based quality of maternal care. This paper identifies and summarizes existing frameworks and tools, and uses a best fit framework analysis to propose a comprehensive framework for assessing facility-based maternal quality of care.

Enhancing Physical and Community MoBility in OLDEr Adults with Health Inequities Using CommuNity Co-Design (EMBOLDEN): Results of an Environmental Scan.

Background: Using the comparatively new environmental scan methodology, a protocol was developed and conducted to inform the co-design and implementation of a novel intervention to promote mobility among older adults in Hamilton, Ontario, Canada. The EMBOLDEN program seeks to promote physical and community mobility in adults 55 years and older who face barriers accessing community programs and who reside in areas of high inequity in Hamilton, and to address the following areas of focus: physical activity, nutrition, social participation, and system navigation supports. Methods: The environmental scan protocol was developed using existing models and drew insights from census data, a review of existing services, organizational representative interviews, windshield surveys of selected high-priority neighbourhoods, and Geographic Information System (GIS) mapping. Results: A total of 98 programs for older adults from 50 different organizations were identified, with the majority (92) supporting mobility, physical activity, nutrition, social participation, and system navigation. The analysis of census tract data identified eight high-priority neighbourhoods characterized by large shares of older adults, high material deprivation, low income, and high proportion of immigrants. These populations can be hard to reach and face multiple barriers to participation in community-based activities. The scan also revealed the nature and types of services geared toward older adults in each neighbourhood, with each priority neighbourhood having at least one school and park. Most areas had a range of services and supports (i.e., health care, housing, stores, religious options), although there was a lack of diverse ethnic community centres and income-diverse activities specific to older adults in most neighbourhoods. Neighbourhoods also differed in the geographic distribution number of services, along with the number of recreational services specific to older adults. Barriers included financial and physical accessibility, lack of ethnically diverse community centres, and food deserts. Conclusions: Scan results will inform the co-design and implementation of the Enhancing physical and community MoBility in OLDEr adults with health inequities using commuNity co-design intervention-EMBOLDEN.

Formal instruction and continuing education engagement as factors improving small animal general practitioners discussing nutrition with clients.

OBJECTIVE: Evaluate whether general practitioners' formal small animal (canine and feline) nutrition instruction in veterinary school and the amount and type of continuing education engagement affect perceived self-reported confidence and frequency in discussing nutrition with clients. SAMPLE: 403 small animal veterinarians who responded to an online survey distributed through the American Animal Hospital Association. PROCEDURES: Veterinarians were surveyed regarding perceived amount of formal instruction received in veterinary school, interest, time committed to self-education, and confidence in both self and staff knowledge in small animal nutrition. RESULTS: Of those veterinarians who responded to the survey, 57.1% (201/352) reported they received "none" or "very little" formal instruction in small animal nutrition, while 151 of 352 answered "some" or "a significant amount." Veterinarians with more formal instruction and veterinarians who reported spending more time in self-education had increased confidence in their own nutritional knowledge (P < .01) and that of their staff (P < .01). CLINICAL RELEVANCE: Veterinarians with self-reported significant formal instruction and veterinarians with higher continuing education engagement were more confident in their knowledge and their staff's knowledge regarding therapeutic and nontherapeutic small animal nutrition. Therefore, it is important for the profession to address veterinary nutrition education gaps in order to increase the veterinary healthcare team's engagement in nutritional discussions with their clients for both healthy and sick pets.

Limitations of COVID-19 testing and case data for evidence-informed health policy and practice.

BACKGROUND: Coronavirus disease 2019 (COVID-19) became a pandemic within a matter of months. Analysing the first year of the pandemic, data and surveillance gaps have subsequently surfaced. Yet, policy decisions and public trust in their country's strategies in combating COVID-19 rely on case numbers, death numbers and other unfamiliar metrics. There are many limitations on COVID-19 case counts internationally, which make cross-country comparisons of raw data and policy responses difficult. PURPOSE AND CONCLUSIONS: This paper presents and describes steps in the testing and reporting process, with examples from a number of countries of barriers encountered in each step, all of which create an undercount of COVID-19 cases. This work raises factors to consider in COVID-19 data and provides recommendations to inform the current situation with COVID-19 as well as issues to be aware of in future pandemics.

Virtual Clinics: A Student-Led, Problem-Based Learning Approach to Supplement Veterinary Clinical Experiences.

The COVID-19 pandemic created an abrupt need for effective remote clinical experiences for senior clinical veterinary students. Subsequently, the authors created virtual clinics. This activity was derived from a problem-based learning (PBL) model wherein students designed clinical cases and participated through virtual role play as clients and clinicians. The purpose of this article is to describe virtual clinics and to report data from focus groups of participating students and faculty facilitators from two institutions regarding the positive and negative aspects of the shift in practice. A few common emerging themes included that case rounds were fun and engaging, students could learn at their own pace, and peer-to-peer learning opportunities had perceived value. Themes are reflected against the pedagogical literature to draw out areas that resonated. Students felt this activity was more engaging than listening to a discussion of a case they had no ownership of, and facilitators agreed that the peer-to-peer interactions added to student engagement. Additionally, students developed deeper knowledge about the underlying disease process and clinical presentation of their case, which required independent and self-directed learning, enabling students to think about a case from a client's perspective. By participating in these activities, students developed skills of classroom-to-clinic transitional value. While virtual clinics should not replace in-person clinical experiences, this activity might be useful to facilitate students' transition from a structured classroom setting to a less-structured clinical experience.

Recent Photosensitizer Developments, Delivery Strategies and Combination-based Approaches for Photodynamic Therapy†.

Photodynamic therapy of cancer (PDT) is a therapeutic technique, minimally invasive, which is currently used to treat cancerous lesions and tumors that have been in the spotlight for its potential over the recent decades. Nonetheless, PDT still needs further development to become a first-option treatment for patients. This review compiles recent progress in several aspects of the current research in the constantly growing area of PDT to overcome the main challenges as an attempt to serve as a guide and reference for newcomers into this research area. This review has been prepared to highlight the use of chemical modifications on photosensitizers to improve their solubility, photostability, selectivity and phototoxicity. Additionally, the use of liposomes and cavitands as drug delivery systems to aid in the biodistribution and bioaccumulation of photosensitizers is presented. Also, the combination of PDT with chemotherapy or immunotherapy as an option to boost and improve treatment outcomes is discussed. Finally, the inhibition of antioxidant enzymes as a strategy for a synergistic effect to ameliorate the performance of the photosensitizers in PDT is presented as an alternative for future researchers.

Oil-based compounding flavors more accepted by feline patients.

OBJECTIVE: To evaluate the voluntary acceptance of 10 commercially available compounding flavors in cats. ANIMALS: 46 healthy cats between 1 and 12 years of age. PROCEDURES: Each cat underwent a 14-day study period consisting of a 4-day acclimation period followed by a 10-day trial period in which each cat was randomly offered 10 different compounding flavors. Owners completed a presurvey along with a daily observation logbook. Kits, including residual amounts of flavors, were returned and weighed to determine residual weight and calculate the amount ingested. RESULTS: Overall, cats did not voluntarily accept most of the compounding flavors; 58.8% (124/211) and 84.5% (267/311) of offered samples of oil-based and water-based compounding flavors, respectively, were rejected or minimally accepted. Cats were significantly (P < .001) more likely to accept oil-based flavors, compared to water-based flavors. The sweet water-based flavors were least accepted, compared to water-based control and water-based savory flavors (P = .040 and P < .001, respectively). Owner-perceived acceptance was moderately correlated with residual flavor weights (Kendall tau [τ] = -0.466; P < .001). Owners were not able to accurately predict which flavors their cats would accept. CLINICAL RELEVANCE: Cats should be offered oil-based compounding flavorings when available, whereas water-based sweet flavorings should be avoided. Owner perception of acceptance is a valid metric to assess flavor acceptance, which can be used in future studies evaluating flavor acceptance. Owners may not accurately predict their cats' flavor preferences, limiting their ability to guide optimal flavor selection.

Employee Mental Health During COVID-19 Adaptation: Observations of Occupational Safety and Health/Human Resource Professionals in Ireland.

Objectives: This study aims to understand mental health issues among Irish employees arising from COVID-19 adaptation from the perspective of Occupational Safety and Health (OSH) and/or Human Resource (HR) professionals. Methods: Fifteen focus groups including 60 OSH/HR professionals from various sectors were conducted covering four predetermined themes. The data were transcribed verbatim, with transcripts entered into Nvivo for thematic analysis incorporating intercoder reliability testing. Results: The mental health impacts among employees are identified from three stages: pre-adaptation, during adaptation, and post-adaptation. Most issues were reported during the second stage when working conditions dramatically changed to follow emerging COVID-19 policies. The identified mental health support from participating organizations included providing timely and reliable information, Employee Assistance Programme (EAP), informal communication channels, hybrid work schedules and reinforcement of control measures. Conclusion: This study explores the challenges facing employees during the different stages of COVID-19 adaptation and the associated mental health impacts. Gender's influence on mental health consultations should be considered when planning for public health emergencies, and further research conducted in male dominated industries.

Small animal general practitioners discuss nutrition infrequently despite assertion of indication, citing barriers.

OBJECTIVE: To determine what perceived factors prevent small animal general practitioners from discussing pet nutrition with clients during healthy and sick pet appointments. SAMPLE: 403 veterinarians in small animal general practice. PROCEDURES: An online survey was used to gather veterinarians' opinions on perceived barriers, knowledge levels, and confidence regarding pet nutrition discussions. RESULTS: Reported barriers to discussing nutrition during healthy pet appointments included client resistance to changing brand (149/359), time constraints (146/359), misinformation online (138/359), and difficulty keeping up with products (132/359). Reported barriers to discussing nutrition during sick pet appointments included client cost concerns (101/349), pet not accepting new food (99/349), and time constraints (83/349). Veterinarians reported discussing nutrition less during healthy pet appointments, compared to sick pet appointments, and were significantly less confident with their knowledge regarding nontherapeutic food, compared to therapeutic food. Veterinarians also reported that they perceived conversations about therapeutic foods to be more positive than conversations about nontherapeutic foods, and veterinarians with more years in practice more commonly reported that there was nothing that would dissuade them from discussing nutrition. Veterinarians who reported barriers to discussing nutrition described a need for resources and reliable information for health-care teams and clients. CLINICAL RELEVANCE: Results demonstrated a substantial gap between veterinarians' assertion that nutrition conversations are indicated and the frequency with which they discuss nutrition during appointments. Veterinarians reported that they felt their nutrition conversations were frequently positive; therefore, it is important to overcome barriers to engage with clients about pet nutrition.

'Communication, that is the key': a qualitative investigation of how essential workers with COVID-19 responded to public health information.

OBJECTIVES: To understand how essential workers with confirmed infections responded to information on COVID-19. DESIGN: Qualitative analysis of semistructured interviews conducted in collaboration with the national contact tracing management programme in Ireland. SETTING: Semistructured interviews conducted via telephone and Zoom Meetings. PARTICIPANTS: 18 people in Ireland with laboratory confirmed SARS-CoV-2 infections using real-time PCR testing of oropharyngeal and nasopharyngeal swabs. All individuals were identified as part of workplace outbreaks defined as ≥2 individuals with epidemiologically linked infections. RESULTS: A total of four high-order themes were identified: (1) accessing essential information early, (2) responses to emerging 'infodemic', (3) barriers to ongoing engagement and (4) communication strategies. Thirteen lower order or subthemes were identified and agreed on by the researchers. CONCLUSIONS: Our findings provide insights into how people infected with COVID-19 sought and processed related health information throughout the pandemic. We describe strategies used to navigate excessive and incomplete information and how perceptions of information providers evolve overtime. These results can inform future communication strategies on COVID-19.

Cassava Frogskin Disease: Current Knowledge on a Re-Emerging Disease in the Americas.

Cassava frogskin disease (CFSD) is a graft-transmissible disease of cassava reported for the first time in the 1970s, in Colombia. The disease is characterized by the formation of longitudinal lip-like fissures on the peel of the cassava storage roots and a progressive reduction in fresh weight and starch content. Since its first report, different pathogens have been identified in CFSD-affected plants and improved sequencing technologies have unraveled complex mixed infections building up in plants with severe root symptoms. The re-emergence of the disease in Colombia during 2019-2020 is again threatening the food security of low-income farmers and the growing local cassava starch industry. Here, we review some results obtained over several years of CFSD pathology research at CIAT, and provide insights on the biology of the disease coming from works on symptoms' characterization, associated pathogens, means of transmission, carbohydrate accumulation, and management. We expect this work will contribute to a better understanding of the disease, which will reflect on lowering its impact in the Americas and minimize the risk of its spread elsewhere.

Community-based group physical activity and/or nutrition interventions to promote mobility in older adults: an umbrella review.

BACKGROUND: Physical activity and a healthy diet are important in helping to maintain mobility with aging. This umbrella review aims to identify group-based physical activity and/or nutrition interventions for community-dwelling older adults that improve mobility-related outcomes. METHODS: Five electronic databases (MEDLINE, Embase, CINAHL, Cochrane CENTRAL, Sociological Abstracts) were searched from inception to December 2021. Eligibility criteria included systematic reviews exploring the effectiveness of physical activity or structured exercise, alone or combined with nutrition interventions on mobility-related outcomes (aerobic capacity, physical function, balance, falls/safety, muscle strength, health-related quality of life/wellbeing). Interventions must have been delivered in a group setting to community-dwelling older adults aged 55+. Two reviewers independently performed eligibility screening, critical appraisal (using AMSTAR 2) and data extraction. The GRADE approach was used to reflect the certainty of evidence based on the size of the effect within each mobility-related outcome category. Older adult/provider research partners informed data synthesis and results presentation. RESULTS: In total, 62 systematic reviews (1 high, 21 moderate, 40 low/critically low quality) were identified; 53 included physical activity only, and nine included both physical activity and nutritional supplements. No reviews included nutrition interventions alone. Combined aerobic/resistance, general physical activity, and mind-body exercise all improved physical function and balance (moderate-high certainty). Aerobic/resistance training improved aerobic capacity (high certainty). Resistance training and general physical activity improved muscle strength (moderate certainty). Aerobic/resistance training and general physical activity are likely to reduce falls among older adults (moderate certainty). There was no evidence of benefit for nutritional supplementation with physical activity. CONCLUSIONS: Group-based physical activity interventions that combine aerobic and resistance, general PA and mind-body exercise can improve measures of mobility in community-dwelling older adults. We found no reviews focused on nutrition only, highlighting a gap in the literature.

Patient and physician perspectives on the use and outcome measures of mHealth apps: Exploratory survey and focus group study.

Objective: Factors that physicians and patients consider when making decisions about using or recommending health apps are not well understood. We explored these factors to better assess how to support such decision making. Methods: We conducted an exploratory cross-sectional study in Ontario using qualitative focus groups and quantitative surveys. 133 physicians and 94 community dwelling adults completed online surveys and we held two focus groups of nine community dwelling participants who had cardiovascular risk factors and an interest in using mHealth apps. Quantitative survey data was analyzed descriptively. Focus groups were audio-recorded and transcribed verbatim prior to inductive thematic content analysis. We integrated the results from the surveys and focus groups to understand factors that influence physicians' and patients' selection and use of such apps. Results: Physicians recommend apps to patients but the level of evidence they prefer to use to guide selection did not align with what they were currently using. Patients trusted recommendations and reviews from medical organizations and healthcare professionals when selecting apps and were motivated to continue using apps when they supported goal setting and tracking, data sharing, decision making, and empowerment. Conclusions: The findings highlight the significance of evaluating mHealth apps based on metrics that patients and physicians value beyond usage and clinical outcome data. Patients engage with apps that support them in confidently managing their health. Increased training and awareness of apps and creating a more rigorous evidence base showing the value of apps to supporting health goals will support greater adoption and acceptance of mHealth apps.

Patient contracts for chronic medical conditions: Scoping review.

OBJECTIVE: To describe how and why patient contracts are used for the management of chronic medical conditions. DATA SOURCES: A scoping review was conducted in the following databases: MEDLINE, Embase, AMED, PsycInfo, Cochrane Library, CINAHL, and Nursing & Allied Health. Literature from 1997 to 2017 was included. STUDY SELECTION: Articles were included if they were written in English and described the implementation of a patient contract by a health care provider for the management of a chronic condition. Articles had to present an outcome as a result of using the contract or an intervention that included the contract. SYNTHESIS: Of the 7528 articles found in the original search, 76 met the inclusion criteria for the final review. Multiple study types were included. Extensive variety in contract elements, target populations, clinical settings, and cointerventions was found. Purposes for initiating contracts included behaviour change and skill development, including goal development and problem solving; altering beliefs and knowledge, including motivation and perceived self-efficacy; improving interpersonal relationships and role clarification; improving quality and process of chronic care; and altering objective and subjective health indices. How contracts were developed, implemented, and assessed was inconsistently described. CONCLUSION: More research is required to determine whether the use of contracts is accomplishing their intended purposes. Questions remain regarding their rationale, development, and implementation.

Health risk assessment of gaseous elemental mercury (GEM) in Mexico City.

Emissions of gaseous elemental mercury (GEM or Hg0) from different sources in urban areas are important subjects for environmental investigations. In this study, atmospheric Hg measurements were conducted to investigate air pollution in the urban environment by carrying out several mobile surveys in Mexico City. This work presents atmospheric concentrations of GEM in terms of diurnal variation trends and comparisons with criteria for pollutant concentrations such as CO, SO2, NO2, PM2.5, and PM10. The concentration of GEM was measured during the pre-rainy period by using a high-resolution active air sampler, the Lumex RA 915 M mercury analyzer. In comparison with those for other cities worldwide, the GEM concentrations were similar or slightly elevated, and they ranged from 0.20 to 30.23 ng m-3. However, the GEM concentration was significantly lower than those in contaminated areas, such as fluorescent lamp factory locations and gold mining zones. The GEM concentrations recorded in Mexico City did not exceed the WHO atmospheric limit of 200 ng m-3. We performed statistical correlation analysis which suggests equivalent sources between Hg and other atmospheric pollutants, mainly NO2 and SO2, emitted from urban combustion and industrial plants. The atmospheric Hg emissions are basically controlled by sunlight radiation, as well as having a direct relationship with meteorological parameters. The area of the city studied herein is characterized by high traffic density, cement production, and municipal solid waste (MSW) treatment, which constantly release GEM into the atmosphere. In this study, we included the simulation with the HYSPLIT dispersion model from three potential areas of GEM release. Emissions from industrial corridors and volcanic plumes localized outside the urban area contribute to the pollution of Mexico City and mainly affect the northern area during specific periods and climate conditions. Using the USEPA model, we assessed the human health risk resulting from exposure to inhaled GEM among residents of Mexico City. The results of the health risk assessment indicated no significant noncarcinogenic risk (hazard quotient (HQ) < 1) or consequent adverse effects for children and adults living in the sampling area over the study period. GEM emissions inventory data is necessary to improve our knowledge about the Hg contribution and effect in urban megacity areas with the objective to develop public safe policy and implementing the Minamata Convention.