The study, led by Mizanur Rahman and colleagues, is notable for its sheer scale. The National Survey on Persons with Disabilities was designed to provide population-level estimates rather than the small clinic-based or district-level samples that have dominated the literature on disability in South Asia. By analysing data across individual, household, and community levels, the researchers were able to apply multilevel mixed-effects logistic regression, a statistical approach that accounts for the fact that people are nested within households and communities and that risk factors operate at each of these layers simultaneously. Crucially, they stratified their models by age, analysing children aged 0 to 17 years separately from adults aged 18 to 95, because the biology and social context of disability differ profoundly between these groups.

The headline number, a national disability prevalence of 2.79 percent with a 95 percent confidence interval of 2.69 to 2.91, is lower than estimates from some international organisations, which have suggested that roughly 15 percent of the world’s population lives with some form of disability. That gap almost certainly reflects differences in definition and measurement rather than any genuine scarcity of impairment in Bangladesh. Survey instruments that rely on self-report or household reporting tend to capture moderate and severe functional limitations while missing many milder impairments, and stigma can suppress disclosure, particularly for intellectual and psychosocial disabilities. Even so, the survey’s consistency and size make the 2.79 percent figure an important benchmark, and the patterns within it are arguably more informative than the headline rate itself.

Physical disability dominated the profile, accounting for 42.44 percent of reported cases, followed by visual impairment at 14.11 percent. Notably, 11.60 percent of people with disabilities reported multiple disabilities, a detail with significant implications for service design. A person with both a physical impairment and a visual one faces compounded barriers to education, employment, and health care, and rehabilitation programmes built around a single impairment category may fail such individuals entirely. The prominence of physical and visual disabilities also points toward preventable causes, including injuries, untreated infections, and age-related conditions, that could be addressed through stronger primary care, occupational safety, and eye health services.

One of the most striking findings concerns sex. Overall, disability was more prevalent among males, but this aggregate picture concealed sharply divergent patterns by age. Among children, girls had 31 percent higher adjusted odds of disability than boys, with an adjusted odds ratio of 1.31 and a confidence interval of 1.13 to 1.52. Among adults, however, no significant sex difference emerged, with an adjusted odds ratio of 1.06 and a confidence interval spanning 0.95 to 1.19. The childhood pattern is particularly concerning in a country where daughters have historically faced disadvantages in nutrition, health care utilisation, and educational investment. Higher odds of reported disability among girls may reflect genuine biological or perinatal differences, but they may also signal that families are more likely to identify and report disability in girls in certain contexts, or conversely that girls with disabilities face compounded neglect. Disentangling these mechanisms is a priority for follow-up research.

Perhaps the most counterintuitive result is the relationship between socioeconomic status and disability. In both age groups, the odds of reporting disability increased with years of schooling and household wealth, the opposite of what a purely causal reading of poverty and impairment might predict. Among adults, community-level literacy was likewise associated with higher odds of disability, while among children the association was reversed, with higher community literacy linked to lower odds. The most plausible explanation is detection bias: wealthier, better-educated households are more aware of what constitutes a disability, more willing to report it to surveyors, and more likely to have accessed diagnostic services, while stigma and limited awareness suppress reporting in poorer and less literate communities. If that interpretation is correct, the true burden of disability in Bangladesh’s most disadvantaged communities is likely substantially higher than the survey suggests, and the observed socioeconomic gradient is a map of underreporting rather than of genuine protection.

Occupational patterns among adults reinforce this interpretive caution. Housewives, students, and blue-collar workers all showed higher adjusted odds of disability than agriculture workers, the reference category. Each of these comparisons can be read in multiple ways. Blue-collar workers may face genuinely elevated risk through hazardous working conditions and injuries, a finding consistent with occupational health research across South Asia. Housewives and students, by contrast, are categories whose composition differs systematically by wealth and education, so the elevated odds may partly reflect reporting behaviour rather than causation. Agriculture workers, who form the reference group, are often among the poorest and least educated, meaning that unmeasured impairment in this group could deflate the apparent risk elsewhere. The authors’ call for caution in interpreting these associations is well founded.

The policy implications of the study are concrete. Rahman and colleagues argue for strengthening community-based disability identification and referral through Bangladesh’s existing primary health-care infrastructure, with particular attention to underserved populations and geographic areas where detection is likely weakest. Bangladesh has an extensive network of community clinics and frontline health workers, and embedding disability screening within routine maternal, child health, and general primary care contacts could dramatically improve case finding without requiring new infrastructure. The researchers also highlight the potential of better coordination between the Ministry of Health and Family Welfare, which controls health services, and the Department of Social Services, which administers disability allowances, rehabilitation programmes, and assistive-device distribution. In practice, many Bangladeshis who are identified with a disability never connect to the social protection schemes designed for them, and the study suggests that closing this administrative gap could deliver immediate benefits.

For a country that has made significant progress on poverty reduction, immunisation, and maternal mortality, the persistence of an invisible disability burden represents both a challenge and an opportunity. The 2021 National Survey on Persons with Disabilities provides the statistical foundation that advocates, planners, and researchers have long lacked, and its stratified, multilevel design offers a template for other low- and middle-income countries attempting similar measurement exercises. The paradoxes it documents, from higher reported disability among wealthier households to the reversal of the literacy association between children and adults, are not statistical curiosities. They are warnings that the data we see are shaped by who gets counted, and that the children and adults least likely to appear in disability statistics may be those most in need of services. Turning a 2.79 percent snapshot into a genuinely inclusive national response will require Bangladesh to treat detection itself as a public health intervention.

Subject of Research: National prevalence and sociodemographic correlates of disability in Bangladesh based on the 2021 National Survey on Persons with Disabilities

Article Title: National burden of disabilities in Bangladesh and its socio-demographic correlates: A 2021 cross-sectional analysis

Article References: National burden of disabilities in Bangladesh and its socio-demographic correlates: A 2021 cross-sectional analysis. (n.d.). https://doi.org/10.1371/journal.pgph.0007463

Image Credits: AI Generated

DOI: 10.1371/journal.pgph.0007463

Keywords: disability, Bangladesh, public health, prevalence, cross-sectional study, multilevel regression, health equity, primary health care, social protection, visual impairment, physical disability, LMICs

The molecular logic of the new classification rests on a small set of defining alterations. Adult-type diffuse gliomas are now divided into three primary entities. Astrocytoma, IDH-mutant is characterized by mutations in the IDH1 or IDH2 genes, typically accompanied by ATRX and TP53 alterations and the absence of 1p/19q codeletion; its grading incorporates the presence of CDKN2A/B homozygous deletion, which confers a grade 4 designation regardless of histology. Oligodendroglioma requires the dual signature of IDH mutation and whole-arm 1p/19q codeletion. Glioblastoma, IDH-wildtype, the most aggressive form, can be diagnosed in any IDH-wildtype diffuse glioma carrying a TERT promoter mutation, EGFR amplification, or the characteristic +7/−10 cytogenetic pattern, even without classic histological features. Pediatric-type gliomas, driven by histone H3 alterations or MAPK pathway dysregulation, form their own molecularly coherent categories. Each of these definitions depends on tests that go far beyond conventional histopathology.

The major international guidelines have converged on this framework. The WHO CNS5, the National Comprehensive Cancer Network, the European Association of Neuro-Oncology, and the Italian Association of Neuro-Oncology all designate IDH1/2 mutation testing as essential, with 1p/19q codeletion assessment required whenever an IDH-mutant tumor is identified. TERT promoter mutation, EGFR amplification, and +7/−10 status are required to establish a glioblastoma diagnosis under WHO criteria, while MGMT promoter methylation is recommended as a predictive biomarker for temozolomide response. The Italian guidelines go further operationally, defining mandatory core tests, integrated grading that incorporates CDKN2A/B deletion, and structured flowcharts that standardize reporting from tissue handling through molecular testing to final integrated diagnosis. On paper, the global standard is clear and consistent.

The problem is that the technologies needed to meet that standard are unevenly distributed. Immunohistochemistry, the workhorse of pathology, costs roughly €290 per test and can detect IDH1 R132H, ATRX loss, p53 accumulation, and H3 K27M within one to two days in a standard pathology laboratory. Fluorescence in situ hybridization, at approximately €795, visualizes 1p/19q deletion and EGFR amplification with high specificity. PCR-based methods, including quantitative PCR, multiplex ligation-dependent probe amplification, and digital PCR, cost between roughly €261 and €600 and cover an impressive range of essential biomarkers, from whole-arm 1p/19q codeletion to TERT promoter mutations and MGMT methylation. Targeted next-generation sequencing panels, at around €1538, offer broader characterization but demand sequencing platforms, bioinformatics infrastructure, and specialized staff. Genome-wide DNA methylation profiling, costing €2000 to €3000 per test, remains concentrated in a handful of reference centers.

Surveys from the Asian Oceanian Society of Neuropathology paint a sobering picture of who can actually access these tools. Fewer than 15 percent of centers in low- and middle-income countries have access to next-generation sequencing, and methylation profiling is virtually absent. Most institutions in these settings rely on immunohistochemistry and limited PCR-based assays. Even within high-income nations, access is stratified: rural and community hospitals in Europe often lack next-generation sequencing and methylation platforms, while in the United States substantial disparities persist between academic institutions and community hospitals in bioinformatics capacity, reimbursement, and neuropathology expertise. In China, genomic capacity has expanded rapidly in major urban centers, yet the ratio of sequencing-capable facilities to population varies by an order of magnitude between coastal metropolitan areas and inland provinces. Japan and South Korea have achieved broader access through national insurance reimbursement for targeted panels, though regional concentration remains pronounced.

The review is emphatic that this is not simply a story of rich centers versus poor ones. The authors argue that presenting sequencing and methylation arrays as universal gold standards reflects the practice of a minority of well-resourced institutions and does not align with global diagnostic realities. For the majority of glioma patients, a tiered strategy built on immunohistochemistry, PCR-based assays, and multiplex ligation-dependent probe amplification yields all the clinically actionable information needed for diagnosis, grading, and treatment planning. Each technique occupies a distinct niche: multiplex ligation-dependent probe amplification remains particularly useful for whole-arm 1p/19q assessment, while digital PCR offers exceptional sensitivity for low-allele-fraction variants such as TERT promoter mutations. No single modality addresses every diagnostic question, and the appropriate test should be determined by the clinical question, not by the available technology.

The economics of inaction are striking. A single cycle of temozolomide administered to a patient whose glioblastoma lacks MGMT promoter methylation, and who therefore derives minimal benefit, often costs more than the methylation assay itself. Without testing, temozolomide is given empirically to all glioblastoma patients despite limited benefit in roughly 60 percent of unmethylated cases. Patients with 1p/19q-codeleted oligodendroglioma who do not receive procarbazine, lomustine, and vincristine chemotherapy with radiation may lose years of survival compared with those treated according to molecular subtype. Misclassification cascades into ineffective therapies, unnecessary toxicity, accelerated progression, earlier salvage treatment, more emergency admissions, and ultimately greater disability, caregiver burden, and lost productivity. The cumulative societal cost of diagnostic inaccuracy, the review concludes, dwarfs the upfront investment in molecular testing.

The consequences extend beyond individual treatment decisions into the research enterprise itself. Contemporary glioma trials are increasingly molecularly driven, and centers without testing capability cannot screen or enroll eligible patients, producing what the authors call diagnostic deserts and trial deserts, regions where patients are excluded from cutting-edge research not because of clinical ineligibility but because of missing infrastructure. Historical trials conducted without molecular stratification are now difficult to interpret, since treatment benefits are often confined to molecular subgroups. Biobanks lacking molecular annotation have limited value for biomarker discovery. At a global scale, the published molecular landscape of gliomas is heavily biased toward populations served by well-resourced centers, potentially overlooking biological features unique to underrepresented regions.

The barriers to change form a self-reinforcing cycle. High costs and unstable funding restrict the test menu and force dependence on send-out testing with long turnaround times. Shortages of neuropathologists, molecular biologists, and bioinformaticians, worsened by brain drain to high-income countries, lead to errors in test selection and interpretation. Non-standardized tissue fixation and inadequate quality control compromise sample integrity, while bureaucratic delays in approving and reimbursing new tests slow adoption. Limited exposure to the full spectrum of diagnostic modalities then prevents local expertise from developing, perpetuating the cycle from the beginning.

The proposed remedy is a three-tiered framework rather than a demand for universal high-end sequencing. Tier 1, essential and universally accessible, combines histopathology and immunohistochemistry with qPCR, multiplex ligation-dependent probe amplification, or digital PCR for the core biomarkers, delivering actionable results in one to five days with minimal bioinformatics. Tier 2 provides targeted sequencing panels through regional hub laboratories for ambiguous cases and trial candidates. Tier 3 concentrates methylation profiling in reference centers serving large populations. Supporting strategies include hub-and-spoke networks endorsed by the Lancet Commission on Diagnostics, telepathology platforms that allow remote expert interpretation, health technology assessments that explicitly weigh the cost of non-implementation, and workforce initiatives such as the MNP Outreach program, which offers free methylation testing to more than 300 patients annually in Pakistan. The authors also call on the WHO to promote regional reference laboratories, define a minimum diagnostic standard achievable with Tier 1 technologies, and negotiate affordable reagent pricing. The central message is one of pragmatic optimism: an accurate, clinically actionable glioma diagnosis is achievable today for most patients using existing, affordable technologies, provided the political will and organizational frameworks exist to deliver them. The alternative is a consolidated two-tiered neuro-oncology in which access to precision medicine is determined by geography rather than need.

Subject of Research: Global disparities in the implementation of molecular diagnostics for glioma classification under the WHO CNS5 framework

Article Title: The Price of Precision: A Critical Review of Molecular Diagnostics in Glioma, From Guidelines to Global Disparities

Article References: Guarnaccia, M., & Cavallaro, S. (2026). The Price of Precision: A Critical Review of Molecular Diagnostics in Glioma, From Guidelines to Global Disparities. Annals of Clinical and Translational Neurology, 13(10), 1968-1977. https://doi.org/10.1002/acn3.70503

Image Credits: AI Generated

DOI: 10.1002/acn3.70503

Keywords: glioma, molecular diagnostics, WHO CNS5, IDH mutation, 1p/19q codeletion, glioblastoma, health economics, global health disparities, next-generation sequencing, MGMT methylation, neuro-oncology, LMICs

Writing in the journal Global Surgical Education, a team describes the implementation and evaluation of a year-long research curriculum developed collaboratively between the American College of Surgeons Health Outreach Program for Equity, known as ACS-H.O.P.E., and the University Teaching Hospital in Lusaka, Zambia. In an accompanying invited commentary, Brian M. Carter of The Ohio State University Wexner Medical Center frames the work as an important contribution to the literature on research capacity building and a potentially replicable model for bidirectional partnerships in global surgery education. The program’s significance lies less in any single result than in the design principles it demonstrates and the honest accounting of where it fell short.

Zambia is an instructive setting. The country pioneered a National Surgical, Obstetric, and Anesthesia Plan, or NSOAP, one of a new generation of national strategies that translate the global surgery agenda into domestic policy. Zambia’s plan explicitly identified research capacity as a core pillar, recognizing that durable gains in surgical care must be driven by data produced in-country and by researchers trained on the ground. Yet the training pipeline has lagged behind the ambition. A recent needs assessment of surgeons across the College of Surgeons of Eastern, Central and Southern Africa region identified faculty development and structured educational content as the areas of greatest perceived need, while surveys of Nigerian surgical trainees and trainers have found mentorship and research training inadequate, with both groups calling for formalized mentorship programs.

The Lusaka curriculum was built to answer those gaps, and its architecture reflects hard-won lessons about what international educational programs can and cannot do. The course ran for twelve months and followed a hybrid virtual-asynchronous format: live sessions delivered over video were paired with recorded lectures that participants could access on their own schedule. That flexibility is not a cosmetic feature. Clinical demands and time zone differences have historically limited participation in international programs, and the pandemic-era shift toward virtual learning has only recently produced evidence that such modalities can work when thoughtfully implemented. In the Zambian program, 80 percent of participants reported using the recorded lectures when they could not attend live sessions, a figure that underscores how asynchronous material can keep a cohort engaged through the interruptions of surgical training.

Equally important is how the curriculum was conceived in the first place. Rather than importing a syllabus designed abroad, the organizers grounded the program in a formal needs assessment and developed it iteratively through binational collaboration. The global surgical education literature has consistently emphasized that successful training partnerships require local leadership, bidirectional knowledge exchange, and alignment with locally identified priorities. The program embodied those principles concretely: a research champion based at the University Teaching Hospital anchored the effort locally, and faculty from the hospital’s School of Public Health led biostatistics instruction. The distinction matters because the history of global health partnerships is littered with programs that collapsed the moment external funding or enthusiasm moved on. Capacity that resides entirely in visiting experts is not capacity at all.

The longitudinal structure also departs from the short-course model that dominates much of international medical education. Research capacity building is increasingly understood as a staged process requiring sustained engagement rather than a discrete training event, and the twelve-month arc allowed progressive skill building from foundational concepts to applied competencies. The evaluation, however, measured confidence rather than scholarly output, and the authors were careful to frame their results accordingly: confidence gains are early-phase indicators in a capacity-building framework, and they must eventually be followed by objective measures of productivity such as abstracts, manuscripts, and grants.

Perhaps the most instructive finding in the report is a negative one. While participants improved across most domains, biostatistics confidence did not improve significantly. The authors acknowledged this limitation transparently and described in detail the modifications they made in response, an iterative quality improvement approach that Carter highlights as essential to educational program development. The result also resonates with broader challenges in research training. Biostatistics is a procedural skill that requires hands-on practice with real datasets, iterative feedback, and sufficient instructional time, elements that are easily constrained by asynchronous delivery and the competing demands of clinical service. The program’s response, adding a dedicated four-day biostatistics workshop, incorporating case-based exercises, and strengthening collaboration with local biostatistics faculty, represents an evidence-informed attempt to close the gap, and future reports on whether those changes work will be valuable to the field.

Mentorship proved equally stubborn. Thirty percent of participants gained a mentor through the program, but 30 percent remained without mentorship at curriculum completion, and participants rated the accessibility of mentorship only three out of five. These numbers align with a wider literature identifying mentorship as both critically important and persistently difficult to deliver in low- and middle-income settings. Effective mentorship in global surgery requires attention to cultural context, clear expectations for mentor-mentee engagement, and protected time for both parties, none of which emerges spontaneously from a video link. The program used a website-based mentorship request form, an innovative mechanism that nonetheless may have been insufficient to overcome time zone differences, competing clinical demands, and the inherent difficulty of establishing relationships virtually. Carter suggests that future iterations might consider more structured mentor-mentee matching, defined expectations for meeting frequency, and integration of mentorship into the curriculum itself rather than treating it as an adjunct. The underlying argument is blunt: if research curricula are to mature, structured mentorship must be treated not as an optional add-on but as core infrastructure.

The study’s limitations are those typical of a feasibility study of a novel educational intervention. The sample was small, just ten participants, the outcomes relied on self-reported confidence, and selection bias is a plausible concern. None of this diminishes the contribution, but it does underscore the importance of subsequent evaluation phases. The field, Carter argues, would benefit from longitudinal follow-up examining objective outcomes: abstracts submitted, manuscripts published, grants obtained, and ultimately whether participants become research mentors themselves, completing the capacity-building cycle. That last measure is the decisive one. The ultimate test of a global surgery education partnership is not how long outside collaborators remain indispensable, but whether the partnership strengthens local capacity enough that leadership, mentorship, and scholarship increasingly reside within the host institution. The authors indicate that objective outcome measures have been incorporated into subsequent iterations of the curriculum, and publishing that data will be essential.

For institutions contemplating similar partnerships, the Zambian experience distills into three practical lessons. Hybrid virtual-asynchronous models can deliver research training across geographic and temporal barriers, but complex skills like biostatistics may demand more intensive, hands-on approaches. Local leadership and institutional embedding are non-negotiable for sustainability. And mentorship, the element most often left to chance, is the hardest to implement well and deserves dedicated design attention. What makes the report notable, beyond its results, is its candor: successes and failures are reported with equal precision, exemplifying the scholarly rigor the field will need as it develops evidence-based approaches to global surgery education. As Carter concludes, the work is a reminder that global surgical education is most valuable when it creates agency, not just access. In a world where five billion people are waiting for safe surgery, the fastest route to them may run through classrooms in Lusaka rather than operating theaters in Washington or London.

Subject of Research: Research capacity building in global surgery education through a binational partnership in Zambia

Article Title: Building research capacity through partnership: a model for sustainable global surgery education

Article References: Carter, B. M. (2026). Building research capacity through partnership: a model for sustainable global surgery education. Global Surgical Education – Journal of the Association for Surgical Education, 5(1), Article 143. https://doi.org/10.1007/s44186-026-00547-x

Image Credits: AI Generated

DOI: 10.1007/s44186-026-00547-x

Keywords: global surgery, research capacity building, surgical education, Zambia, mentorship, biostatistics training, LMICs, NSOAP, hybrid learning, curriculum design, ACS-H.O.P.E, partnership

A new analysis published in Biomedical Engineering Education argues that part of the solution lies not in new devices alone, but in how engineers are trained to create them. The paper, from researchers at the Johns Hopkins Center for Bioengineering Innovation and Design, known as CBID, examines more than a decade of the center’s global health track and concludes that a specific educational model, one that is integrated, immersive, and relentlessly iterative, can turn graduate students into innovators whose ideas actually reach patients. The study is the first structured translation of CBID’s innovation framework into global health terms, and its results offer a rare quantitative look at what happens when design education is built around the messy realities of low-resource health systems rather than the tidy specifications of wealthy ones.

The problem the program set out to solve is well documented. Traditional biomedical engineering education, particularly in the United States, emphasizes capstone design projects that prepare students for the American medical device industry. Students learn to optimize technical performance and satisfy end-user requirements, but they rarely grapple with the systems-level constraints that determine whether a technology is adopted in a low-income country: delivery systems, workforce capacity, maintenance and spare parts, supply chains, financing, regulation, data systems, trust, and cultural fit. A device that performs brilliantly on a benchtop in Baltimore can fail completely in a rural clinic if nobody can power it, repair it, or afford it. The CBID team argues that this gap between technical excellence and real-world feasibility is a core reason so many healthcare innovations never produce population-level outcomes in low- and middle-income countries.

At the heart of the CBID approach is what the center calls the Spiral-Iterative Innovation model, a framework that extends Barry Boehm’s 1988 spiral model for software development and its later adaptation for medical devices, while borrowing principles from the lean startup movement. The model organizes every issue essential to a healthcare solution’s success into four quadrants: clinical and public health, business and sustainability, technical, and entrepreneurship or execution. The central assumption is radical in its simplicity. An unmet need cannot be fully understood until all four aspects are considered, and complete information for any of them is never available at the start of a project. Instead of finishing technical development before validating clinical and business assumptions, as the traditional bench-to-bedside approach does, teams must advance in all four quadrants simultaneously, at a depth appropriate to the project’s stage, building evidence and reducing risk with each outward turn of the spiral.

This simultaneity is what distinguishes CBID from other leading frameworks. Stanford’s Biodesign program, widely respected in the field, addresses the same four areas but largely in sequence, which can mean that a critical constraint in one domain surfaces only after significant resources have been committed elsewhere. The lean startup method iterates rapidly but lacks specificity to healthcare’s regulatory and multi-stakeholder complexity. In the CBID model, each iteration ends with a stage gate at which students and faculty verify that every quadrant has been addressed, then decide whether to continue, pivot, or kill the project. Because effort in each quadrant is kept to the minimum the stage requires, the cost of changing direction stays low. The authors describe the framework with a memorable phrase: it puts the “due” in due diligence, preventing students from over-investing in the technical work they naturally gravitate toward while neglecting the business and execution questions that will ultimately decide the project’s fate.

The curriculum that carries this model is built on several pillars. Projects cannot even begin without a local partner, such as a university, hospital, or nongovernmental organization in the target country, who provides access to stakeholders and guides the work. Students receive formal lectures on global public health and cross-cultural collaboration, then spend roughly a month doing in-country field immersion, conducting ethnographic interviews and observations organized by their partners. Projects are deliberately longitudinal, often spanning multiple years with structured handoffs between cohorts, and each team is supported by a Global Advisory Committee that functions like a cross-functional thesis committee. Funding is secured project by project, and industry partners that join are required to commit to access-oriented pricing and non-exclusive licensing for low- and middle-income country deployment. The academic year itself unfolds in three phases: needs identification culminating in a landscape analysis and field trip, solution concept selection through structured ideation tools like SCAMPER, MECE maps, and morphological boxes, and finally de-risking through prototyping, validation experiments, and business model development.

To evaluate whether any of this actually works, the researchers compiled a database of every global health project since the track’s founding in 2011 and surveyed program alumni. The results are striking. Of sixty-three global health projects completed to date, twenty-one achieved major translational impact, including field pilots, clinical studies, patents, licensing deals, or market introduction. One hundred seventeen alumni responded to the survey, a thirty-nine percent response rate across all graduating years. Among respondents, seventy-seven percent developed prototypes, more than half collected clinical feedback, nearly a third conducted pilot studies, and none reported that their project failed to progress at all. Five projects spun out startups, three of which have reached commercialization, including the nonprofit telehealth platform Intelehealth and the mosquito surveillance venture behind VectorCam. Seven projects licensed their intellectual property to established companies such as Laerdal Global Health, Bosch, Medtronic, Boston Scientific, and DuPont. One licensed technology, HemoGlobe, a noninvasive anemia screening tool commercialized by Bosch, is now in wide use across India and neighboring countries.

The funding trajectory tells its own story. During the academic year itself, ten of the highest-impact projects secured at least six hundred sixty thousand dollars in external funding. After graduation, eleven projects attracted more than twenty-six and a half million dollars, including a one million dollar grant from the National Cancer Institute for the CryoPop cooling device, eight and a half million dollars for Intelehealth, and five point six million dollars from the Gates Foundation for vector control work. At least fourteen patents have been filed across eleven projects, and twelve projects have documented field pilots or clinical studies, including randomized controlled trials. Thirty-three percent of the highest-impact portfolio remains active in ongoing development or commercialization as of 2025.

Just as important as the project outcomes is what alumni say the training did to them. Respondents reported gains in cross-cultural collaboration, systems thinking, managing conflicting stakeholder incentives, ethnographic research, and frugal design, the art of building effective solutions under severe resource constraints. Field immersion was rated the single most valuable component, with eighty-three percent of alumni calling it high or highest value, even among students for whom global health was only a secondary motivation. While relatively few graduates entered global health careers immediately, twenty-two reported first jobs aligned with global health systems, and several were hired directly by partner organizations, including one alumnus who rose to Director of Impact and Implementation at Laerdal Global Health. The authors interpret this pattern carefully: such programs may not dramatically increase the number of engineers entering global health, but they broaden how all graduates approach engineering practice, instilling what they call foundational innovation literacy that transfers to any multidisciplinary environment.

The study is honest about its limits. Alumni participation was incomplete and may introduce response bias, outcomes were reported at the individual level for team projects, and the analysis is descriptive rather than comparative. Alumni themselves offered pointed suggestions for improvement: narrower project scoping, deeper long-term partner engagement, more structured support after field immersion, and earlier integration of business and regulatory planning. Still, the central finding stands as a challenge to engineering educators everywhere. In a world where the disease burden falls hardest on those with the least access to innovation, the CBID model demonstrates that experiential, partner-driven, iterative training can produce both implementable solutions and engineers equipped to design responsibly within complex, resource-constrained systems. As the World Health Organization’s 2023 call to action urges the global community toward health innovation for all by 2030, this Johns Hopkins experiment suggests that the pipeline of capable innovators may be just as critical as the technologies themselves.

Subject of Research: Experiential education models for training biomedical engineers in global health innovation

Article Title: Teaching Global Health Innovation: An Integrated, Immersive, and Iterative Approach

Article References: García del Barrio Cervera, S., Zhou, S., Parikh, K. S., Rincon Torroella, M., Yazdi, Y., & Acharya, S. (2026). Teaching Global Health Innovation: An Integrated, Immersive, and Iterative Approach. Biomedical Engineering Education. https://doi.org/10.1007/s43683-026-00244-7

Image Credits: AI Generated

DOI: 10.1007/s43683-026-00244-7

Keywords: global health, biomedical engineering education, experiential learning, innovation, human-centered design, low-resource settings, medical devices, Johns Hopkins CBID, spiral innovation model, technology translation, LMICs, alumni survey

The International Health Regulations, revised in 2005 after earlier versions proved inadequate, require all 196 signatory states to develop core capacities for detecting, reporting, and responding to public health events at their borders. Under the framework, countries must designate Points of Entry, including international airports, seaports, and major ground crossings, where routine health screening, emergency medical services, and communication systems must be available around the clock. When an event rises to the level of a Public Health Emergency of International Concern, as COVID-19 did in January 2020, these entry points become critical nodes in a worldwide surveillance and containment network. Yet the regulations have long been implemented unevenly, particularly in resource-constrained settings, and the new study set out to document precisely where those implementation gaps lie in Bangladesh.

The research team conducted an exploratory qualitative study between October 2022 and June 2023, in the aftermath of the pandemic’s acute phase. They selected four designated Points of Entry: Hazrat Shahjalal International Airport, the country’s busiest international air gateway; Shah Amanat International Airport in Chattogram; Chittagong Seaport, one of the largest maritime hubs in South Asia; and Benapole Ground Crossing, the principal land border crossing between Bangladesh and India. Data collection involved 30 interviews in total, comprising 20 in-depth interviews with frontline service providers and port users, and 10 key informant interviews with decision-makers and experienced service providers. All interviews were transcribed, coded, and subjected to thematic analysis using ATLAS.ti software, version 7.5.10, allowing the researchers to identify recurring patterns in how officials and travelers experience border health operations.

The central finding is stark: the study revealed more challenges than enablers on both the regulatory and public sides of IHR-2005 implementation. Among the most fundamental problems was a lack of understanding of the regulations themselves and their role in global infectious disease prevention and control. This is not a trivial administrative detail. If the officers stationed at an entry point do not grasp what the framework requires of them, or why it matters, the entire architecture of border health security weakens at its foundation. The researchers also identified inadequate training on IHR-2005 as a persistent barrier, compounding the knowledge deficit and leaving staff ill-prepared to execute the screening, reporting, and coordination duties the regulations demand.

Human resources emerged as another severe constraint. The study documented a critical shortage of personnel at the entry points, a problem familiar across many low- and middle-income countries where health workforces are stretched thin and border health posts compete with hospitals and clinics for scarce staff. Screening travelers for symptoms, managing health declarations, and responding to suspected cases all require trained people on the ground, and without them even well-designed protocols exist only on paper. The shortage interacts with the training gap in a damaging cycle: too few staff means those who are present cannot be spared for training, while untrained staff cannot build the institutional competence that would justify expanding the workforce.

Practical logistics added further friction. The researchers found limited availability of ambulances for transporting ill travelers, meaning that even when a potentially infectious passenger was identified, moving that person safely to a treatment facility could be difficult or delayed. Health offices were often inaccessible or not conveniently located at every Point of Entry, fragmenting the chain of command and slowing communication between border staff and the health authorities who must authorize and support public health actions. On the public side of the counter, the study recorded uncooperative behavior from travelers, a challenge that frontline screeners worldwide have encountered but which carries particular weight in crowded, high-throughput crossings where delays provoke frustration and evasion.

Not all entry points fared equally. The study found that Benapole Ground Crossing encountered the most significant obstacles in ensuring effective implementation of the regulations, and that the overall environment there was suboptimal. This finding matters because Benapole is one of the busiest land crossings in South Asia, handling enormous daily flows of passengers and goods between Bangladesh and India. Land crossings are inherently harder to manage than airports: passenger processing is less structured, infrastructure is often older, and the sheer volume of movement makes comprehensive screening difficult. By contrast, the other designated Points of Entry, including the two international airports and Chittagong Seaport, demonstrated good communication and coordination capacities, available medical and technical services, and a generally good environment, suggesting that implementation success in Bangladesh is less a uniform national failure than a uneven landscape in which some sites have achieved functional capacity while others lag far behind.

The methodological contribution of the study is also notable. According to the authors, no qualitative research on IHR-2005 implementation at designated Points of Entry in Bangladesh had been conducted before, making this the first in-depth account of how the framework operates, or fails to operate, at the country’s borders. Qualitative approaches of this kind capture dimensions that quantitative audits miss: the lived experience of officers who lack clear guidance, the frustrations of port users navigating health checks, and the informal workarounds that develop when formal systems fall short. The study received ethical approval from the Institutional Review Board of icddr,b under research protocol number PR-22149, with informed written consent obtained from all participants and transcripts anonymized and stored in password-protected databases. The work was funded by the Disease Control program of the Directorate General of Health Services, with core support from the governments of Bangladesh and Canada.

The findings carry implications well beyond Bangladesh’s borders. The COVID-19 pandemic demonstrated that a pathogen detected in one country can circle the globe within days, and that the strength of the weakest border health system can determine the speed of international spread. The World Health Organization has repeatedly emphasized that global health security depends on every country meeting the core capacity requirements of the regulations, and independent assessments have consistently shown that many low- and middle-income countries remain short of those benchmarks. Bangladesh’s experience illustrates the specific mechanisms by which the gap opens: knowledge deficits among staff, inadequate training pipelines, chronic understaffing, missing transport and infrastructure, and public non-cooperation. Each of these is addressable, but only with sustained investment and political attention rather than emergency-time improvisation.

The researchers conclude that the implementation of IHR-2005 at designated Points of Entry in Bangladesh faces significant challenges that hinder its effectiveness, and that addressing these barriers is essential to strengthen enforcement of the regulations and enhance the country’s ability to prevent and control the spread of infectious diseases at its key entry points. Their evidence suggests a clear agenda: systematic training on the regulations for all border health staff, recruitment to close the human resource gap, guaranteed ambulance and transport capacity for ill travelers, and health offices physically present and accessible at every designated entry point, with particular urgency at Benapole Ground Crossing. As the world prepares for future pandemics that experts consider inevitable rather than hypothetical, studies like this one provide the granular, ground-level evidence that turns abstract international commitments into workable practice. The borders of Bangladesh, like those of many countries, are only as secure against infectious disease as the people, training, and equipment stationed there, and this study shows exactly where those defenses need reinforcement.

Subject of Research: Implementation of the International Health Regulations 2005 for infectious disease control at designated Points of Entry in Bangladesh

Article Title: Critical gaps in infectious disease prevention and control: insights from IHR-2005 implementation enablers and challenges at key entry points in Bangladesh

Article References: Dutta, G. K., Hasan, M. K., Sanin, K. I., Roy, B. R., Ali, M. S., Islam, M. N., Islam, M. S., Khan, M. N. A., Mahmud, M., Nadia, N., Noushin, F., & Tofail, F. (2026). Critical gaps in infectious disease prevention and control: insights from IHR-2005 implementation enablers and challenges at key entry points in Bangladesh. BMC Public Health. https://doi.org/10.1186/s12889-026-29658-2

Image Credits: AI Generated

DOI: 10.1186/s12889-026-29658-2

Keywords: IHR-2005, Points of Entry, Bangladesh, global health security, infectious disease control, border health, COVID-19, public health emergency, qualitative research, LMICs, Benapole Ground Crossing, WHO

The problem the initiative set out to address is structural. Health policy and systems research is an interdisciplinary field focused on how health systems shape and implement policy, and it is considered critical to achieving the United Nations Sustainable Development Goals. Unlike clinical practice guidelines, which target care for individual patients, health systems guidelines aim to improve the efficiency, equity and quality of care across an entire system. Yet there is a persistent gap in the availability and quality of such guidelines designed within low- and middle-income countries. As a result, health system stakeholders in these settings often rely on guidelines produced by the World Health Organization or by high-income countries — documents that are frequently not adapted to local needs, contexts or political realities, and that often clash with the priorities of the policymakers expected to implement them.

To close this gap, the WHO Alliance for Health Policy and Systems Research funded six research teams from Colombia, Ghana, India, Mozambique, Nigeria and Zambia through the RAISE portfolio. Each team was required to partner with at least one policymaker or knowledge user — someone positioned to use research results to make informed decisions — to support the practical uptake of the guidelines. The projects were strikingly diverse: home visit guidelines in Ghana, prioritization of WHO guidelines in Colombia, antenatal care guidelines in tribal communities in India, cholera control guidelines in Zambia, a WHO digital intervention guideline for mental health system strengthening in Nigeria, and guidelines to reduce primary care waiting times in Mozambique. Selection followed a rigorous peer review process in which 21 eligible proposals out of 27 submissions were scored by 16 reviewers on team qualifications, methods quality, engagement strategy, impact potential, innovation, feasibility and value for money, with scores ranging from 45.00 to 90.67 before an international adjudication panel made the final choices.

Following a competitive process, the Alliance selected the Knowledge Translation Program at St. Michael’s Hospital–Unity Health Toronto, in partnership with the South African Cochrane Centre and the WHO Ethiopia country office, to act as the Technical Support Centre. Crucially, the centre’s approach was rooted in integrated knowledge translation, a methodology in which the knowledge users themselves — the RAISE researchers, trainees and policymakers — were engaged in designing the content and delivery of the support program. This matters because integrated knowledge translation is known to improve buy-in, increase evidence uptake and reduce research waste. It stands in deliberate contrast to the one-size-fits-all or so-called blueprint models that have dominated past capacity-strengthening efforts, which systematic reviews suggest are often driven by high-income country actors pursuing their own spotlight topics rather than the priorities identified by LMIC actors themselves.

The design process began with a needs assessment. In August 2019, 22 participants from the six countries — 10 men and 12 women, including seven principal investigators, six co-investigators, two knowledge users and six research staff — completed a survey with a 63 percent response rate. All teams reported difficulty identifying their specific methods needs before their projects had begun, but six teams requested rigorous training in evidence-based implementation methods, with additional requests covering barrier and facilitator assessments, stakeholder engagement and qualitative analysis. The resulting program had several components: a mandatory three-day in-person inception workshop in Istanbul, Turkey in September 2019; seven pre-recorded webinars delivered between November 2019 and January 2021 through the Canvas online learning platform; online discussion boards; virtual workshops held from April to July 2021 after the COVID-19 pandemic forced the cancellation of planned in-country visits; and ongoing one-to-one coaching calls and email support from methods experts.

The inception workshop covered the full methodological arc of guideline work: introduction to knowledge translation and health policy and systems research, identifying health system gaps, appraising guideline quality using established tools, prioritizing recommendations through Delphi processes, adapting guidelines, mapping barriers and enablers to implementation strategies, and evaluating implementation quality alongside ethical considerations. Participants rated the workshop a mean 6.30 out of 7, praising the quality and applicability of the content and the opportunity to collaborate across teams. The webinars were also well received, rated between 4 and 5 out of 5, with the session on the AGREE II approach to guideline development, evaluation and adaptation drawing the highest engagement. The on-demand format proved essential for teams working across time zones and, as it turned out, through a pandemic.

The evaluation used a mixed-methods design across three phases, applying the Durlak and Dupre process evaluation framework, validated self-efficacy surveys administered at baseline, 12 and 24 months, and semi-structured exit interviews coded thematically with inter-rater reliability checks. The headline quantitative finding was encouraging but nuanced: mean scores for eight of nine research capacity outcomes improved over time, and the improvement in researchers’ ability to develop evidence-based knowledge translation interventions reached statistical significance between 12 and 24 months (Z = −2.93, p < 0.05). The absence of significant change in the other outcomes was attributed to relatively high baseline scores, the small sample size, staff turnover and pandemic-related disruptions to participation. Twenty-one participants responded at baseline, eleven at 12 months and fourteen at 24 months, with only five completing all three time points — an attrition pattern the authors acknowledge as a limitation that may have introduced response bias.

The qualitative findings may prove the most valuable for the field. Teams identified consistent barriers to adapting and implementing health systems guidelines: competing health system structures and stakeholder interests, lack of available data, poorly maintained field equipment for data collection, and insufficient training among staff tasked with implementation. The COVID-19 pandemic compounded these with project delays, reduced human resources, difficulty engaging stakeholders virtually and community fears that study personnel might spread the virus. Yet the enablers the teams identified form a practical playbook. Partnering with health system stakeholders at project inception rather than at study end sustained engagement and buy-in throughout. Employing a multi-sectoral approach that reached beyond the health sector, allocating financial resources for data collection and partnership strengthening, adopting rapid analysis methods to keep qualitative work moving, and building the competencies of the implementation team — a role the Technical Support Centre itself played — all helped projects survive and, in many cases, thrive.

Participants were candid about the program’s friction points as well. Some felt overwhelmed by the sheer number of supports and activities, struggling to balance capacity-strengthening sessions with actual research implementation. Quarterly monitoring templates were seen as helpful for accountability but time-consuming and repetitive. Knowledge user participation in the evaluation was limited by turnover, heavy workloads and pandemic constraints, and internet connectivity varied enough by country that on-demand resources were not equally accessible — page view statistics likely undercount viewership because teams downloaded webinars and watched them together offline. These honest appraisals are part of what makes the study useful: it documents not just what worked but where the model strained.

The authors conclude that the Technical Support Centre offers a replicable model for supporting health policy and systems research capacity in LMICs, with three defining features: a user-driven approach that lets stakeholders determine priorities and activities, flexibility to adapt supports as needs evolve, and multi-modal delivery that extended benefits beyond the core teams to their networks, trainees and associated institutions. Participants recommended sustaining the network of RAISE teams and connecting WHO regional and in-country offices to keep the collaboration alive. As health systems worldwide continue to grapple with pandemic aftershocks and competing priorities, the study’s central lesson resonates well beyond its six countries: capacity strengthening works best when it is not something done to researchers in low- and middle-income countries, but something built with them, on their terms, from the very beginning.

Subject of Research: Implementation and evaluation of a technical support center for health systems guideline research capacity strengthening in low- and middle-income countries

Article Title: Implementation and evaluation of a technical support center for the Research to Enhance the Adaptation and Implementation of Health Systems Guidelines in LMICs [RAISE] initiative

Article References: Fahim, C., Pratt, J., Purewal, A., Marsot-Shiffman, L., de Launay, K. Q., Baddeliyanage, R., Davenport-Huyer, L., Yangchen, S., Gebregiorgis, A. H., Wiysonge, C. S., Tricco, A. C., Puchalski-Ritchie, L., Pham, B., Tuncalp, O., Langlois, E. V., Marten, R., & Straus, S. E. (2026). Implementation and evaluation of a technical support center for the Research to Enhance the Adaptation and Implementation of Health Systems Guidelines in LMICs [RAISE] initiative. Health Research Policy and Systems, 24(S1), Article 73. https://doi.org/10.1186/s12961-026-01462-9

Image Credits: AI Generated

DOI: 10.1186/s12961-026-01462-9

Keywords: health policy and systems research, capacity strengthening, LMICs, knowledge translation, guideline adaptation, implementation research, WHO Alliance for HPSR, RAISE initiative, technical support centre, integrated knowledge translation, health systems guidelines, COVID-19

The review, conducted by Mahlodi Esther Masekela, systematically mapped the literature on BTEX emissions from household firewood combustion published between 1994 and 2025, following the Arksey and O’Malley scoping framework and adhering to PRISMA-ScR reporting guidelines. Searches across ScienceDirect, Web of Science, Google Scholar, and Scopus identified 583 records, which were screened down to just five eligible peer-reviewed studies. That tiny number is itself a striking finding: after three decades of research, only a handful of investigations have quantitatively characterized BTEX emissions from the specific firewood species burned in domestic cookstoves, and the review’s central concern is what those few studies leave out.

The core methodological problem is the mismatch between study design and real-world fuel use. Four of the five included studies—80 percent—examined only single firewood species, burning one taxonomically distinct wood type at a time. But households in low- and middle-income countries rarely do this. Research in South Africa has documented that families typically use bundles containing up to six different tree species, while studies in Ethiopia have found that mixed fuels, principally wood combined with animal dung, are the most common cooking fuels. Laboratory work has shown that blending fuels fundamentally alters both the total volatile organic compound concentrations and the relative proportions of individual compounds, meaning single-species emission profiles may simply not represent what happens in a real kitchen.

Geography compounds the problem. Four of the five studies were conducted in high-income countries, mostly in Europe—Portugal, Sweden, and Finland—plus one in the United States, while only a single study, from South Africa, represents the low- and middle-income country context. This distribution is starkly inverted relative to the disease burden: firewood accounts for roughly 25 to 60 percent of energy consumption in middle-income countries and up to 60 to 95 percent in developing contexts, while high-income countries derive less than 5 percent of their energy from wood, largely burning it in modern stoves designed to minimize emissions. All five studies were conducted in countries with less than 10 percent primary reliance on polluting fuels and cookstoves, meaning the existing evidence comes almost exclusively from low-exposure settings while the populations facing the highest exposures in Africa and Asia remain critically under-represented. Africa’s air quality monitoring density—just 0.03 monitors per million inhabitants—leaves BTEX emission factors and source profiles largely absent precisely where they are most urgently needed.

Setting matters just as much as species. Most of the reviewed studies were conducted in purpose-built laboratory combustion facilities, and none achieved a full rating for real-world setting representativeness in the review’s quality appraisal. The only study that approached household realism, the South African investigation in Senwabarwana, used a simulated kitchen structure and still could not capture the full variability of actual kitchen geometry, ventilation, and occupant behavior. This matters because field studies of other products of incomplete combustion have repeatedly shown that real-world emissions exceed laboratory measurements and display far greater variability, reflecting inconsistent stove operation, fluctuating fuel quality, and diverse user behaviors that controlled experiments systematically exclude. When laboratory data are used for population-level exposure assessment without field validation, the review warns, health burden estimates risk being systematically biased.

The synthesis also revealed a consistent chemical hierarchy that cuts across geography and methodology. Benzene was the most consistently reported and highest-emitting BTEX compound in every study, with emission profiles generally following the pattern benzene, then toluene, then ethylbenzene, then xylenes. Among studies reporting comparable emission factors in milligrams per kilogram, benzene values ranged from 108 mg/kg for European beech to 1,500 mg/kg for birch logs—a 13.9-fold difference across single-species combustion alone, though the review cautions that differences in adsorbent chemistry between the studies’ sampling methods may account for some of this spread. Benzene’s dominance echoes broader literature on residential wood combustion and suggests it may be a fundamental feature of firewood combustion chemistry rather than a species-specific artifact, arising from the thermal degradation of lignin, the principal aromatic precursor in wood. Still, with only two studies providing complete four-compound profiles, the review frames this pattern as preliminary rather than definitive.

Reporting practices added further obstacles to comparison. Only two of the five studies reported a complete BTEX profile; three omitted ethylbenzene entirely, and one reported benzene only. Ethylbenzene, a Group 2B possible carcinogen that is relatively more abundant in biomass-burning profiles and can help distinguish those emissions, was systematically absent from 60 percent of the studies, potentially due to co-elution with xylene isomers and intermittent detection. The studies also used incompatible metrics: four reported emission factors, which characterize fuel or stove performance, while others reported ambient concentrations relevant to health risk assessment. These quantities are not interchangeable, and the review argues that both are needed simultaneously to serve source characterization and exposure assessment alike. Analytical approaches further fragmented the evidence, spanning adsorbent-based gas chromatography, whole-air canister sampling, and Fourier-transform infrared spectroscopy, each with distinct trade-offs in detection limits, sample stability, and susceptibility to interference.

The health stakes are considerable. Households in low- and middle-income countries typically cook three times a day, four to six hours per session—roughly 21 meals per week, far above the global average—implying chronic exposure far exceeding the 365-day threshold used in toxicology. Benzene targets the hematopoietic system, with prolonged exposure linked to aplastic anemia and leukemia, while toluene is associated with cognitive impairment and cardiac sensitization, and xylenes with headaches and memory deficits. Simultaneous co-exposure complicates matters further: BTEX compounds compete for shared metabolic pathways involving the enzyme CYP2E1, producing less-than-additive metabolism but potentially greater-than-additive neurological effects as unmetabolized parent compounds persist in the bloodstream. With benzene concentrations measured at combustion sources running thousands of times above the World Health Organization’s most stringent risk-based reference level, and BTEX vapors persisting indoors for one to fourteen days, poorly ventilated kitchens may never fully clear between cooking episodes.

The review concludes that the effect of mixed-species combustion on BTEX emissions remains an unresolved gap in the literature, and it calls for future studies designed around the mixed fuel bundles and fuel stacking practices—wood co-burned with coal, charcoal, crop residues, and dung—that actually characterize household energy use in low- and middle-income settings, conducted within real homes rather than laboratories. Standardized full-profile BTEX reporting, integration of combustion frequency and ventilation data, and field-based exposure measurements are identified as priorities. Until the evidence base aligns with the conditions under which exposure actually occurs, the review warns, the populations bearing the greatest burden from firewood smoke will remain the least represented in the science meant to protect them.

Subject of Research: Methodological gaps in BTEX emission studies from household firewood combustion and their implications for indoor air pollution exposure assessment.

Article Title: Methodological Gaps in BTEX Emission Studies from Household Firewood Combustion: Implications for Exposure Assessment and Indoor Air Pollution

Article References: Masekela, M. E. (2026). Methodological Gaps in BTEX Emission Studies from Household Firewood Combustion: Implications for Exposure Assessment and Indoor Air Pollution. Environmental Challenges, Article 101665. https://doi.org/10.1016/j.envc.2026.101665

Image Credits: AI Generated

DOI: 10.1016/j.envc.2026.101665

Keywords: BTEX, benzene, firewood combustion, indoor air pollution, household energy, exposure assessment, scoping review, LMICs, volatile organic compounds, clean cooking, wood smoke, public health