International Journal of Hygiene and Environmental Health
○ Elsevier BV
Preprints posted in the last 30 days, ranked by how well they match International Journal of Hygiene and Environmental Health's content profile, based on 11 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.
Hoque, S. M. A. U.; Islam, M. K.; Hasan, M. K.; Banu, B.; Hossain, Z. Z.; Sharif, M. M.; Baset, K. u.
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Background. Safely managed drinking-water monitoring under Sustainable Development Goal target 6.1 uses source-water quality, yet Escherichia coli is common in household drinking water in Bangladesh despite near-universal improved sources. We compared source and household point-of-use (POU) E. coli detection within households and estimated how the safely managed estimate changes if POU replaces source E. coli. Methods. Cross-sectional secondary analysis of the Bangladesh MICS 2025 water-quality subsample (February-June 2025; detection >=1 colony-forming unit/100 mL). We classified 5,944 households with readable paired results into four joint patterns and, exploratorily, examined POU detection among negative-source households and two-week diarrhoea in children under five with survey-weighted modified Poisson models. Results. E. coli was detected in 47.4% of source and 84.8% of POU samples; only 12.7% of households were negative at both. Among negative-source households, 75.8% had E. coli in household water, versus 94.7% with a detected source, persisting (33.3%) even direct from the source. The JMP-aligned safely managed estimate was 42.5% (95% CI 40.8-44.1); substituting POU for source E. coli gave 12.6% (11.4-13.8), not an SDG indicator estimate. The diarrhoea prevalence ratio for POU detection (1.04, 0.59-1.86) was too imprecise to interpret. In exploratory spatial analysis, POU detection clustered geographically (Moran's I 0.16 cluster level, 0.31 district level, both p<0.001) and was independently associated with lower elevation (odds ratio 0.62, 0.56-0.70) and longer travel time to healthcare (1.65, 1.29-2.12); five districts had complete detection among 84-94 households tested. Conclusions. Source and POU classifications differed substantially; the survey cannot show where or when contamination occurred. Contamination was spatially clustered, arguing against pure noise and pointing to districts for follow-up. The findings support evaluating standardised POU sampling as a complement to source-based monitoring, with targeted follow-up and cross-season, cross-country replication.
Hoque, S. M. A. U.; Islam, M. K.; Hasan, M. K.; Naher, T.; Sharif, M. M.; Hossain, Z. Z.; Banu, B.; Baset, K. u.
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Background: Chronic arsenic exposure in drinking water causes skin lesions and cancers and raises infant, cardiovascular and all-cause mortality in Bangladesh. National surveys tested source water in 2012-13, 2019 and 2025 with different kits, so the trend is uncertain. Objectives: We estimated how arsenic in source water changed after laboratory adjustment of 2012-13 readings, and how many people remained exposed. We also assessed whether districts high in earlier surveys held most people exposed in 2025. Methods: We analysed 11,624 households in three Multiple Indicator Cluster Surveys. We counted arsenic strictly above 10 and 50 parts per billion (ppb). Results: Estimates reproduced published 2019 and 2025 tables. After laboratory adjustment of 2012-13, the share above 10 ppb fell from 24.0% to 14.4% (adjusted ratio 0.61, sampling 95% CI 0.55 to 0.67; 0.69 with interview month). Above 50 ppb it fell from 10.9% to 8.6% (0.80, 0.69 to 0.93; 0.93 with month). Most of the fall at 10 ppb occurred within source types. Without false positives, it would vanish only if later kits detected 61% of sources above 10 ppb. About 26 million people used such water in 2025 (kit scenarios 23 to 32 million). The 25 districts high in 2012-13 and 2019 held 39% of the population but 72% of those exposed (bootstrap 95% interval 60 to 76). Clustering was evident, but no district was a significant hotspot. Conclusions: Arsenic above 10 ppb was lower in 2025 than in 2012-13, but the size of the fall depends on unverified later kits. Change at 50 ppb and since 2019 was unclear after month adjustment. One household in seven exceeded the WHO guideline in 2025. Districts found high earlier held most exposed people, supporting prioritised well testing there alongside broader surveillance. Future surveys need one kit with a laboratory cross-check.
Chronister, B. N. C.; Parrish, E. M.; Lopez-Paredes, D.; Suarez-Torres, J.; Quynh, A.; Martinez, D.; Bradman, A.; Moore, R. C.; Suarez-Lopez, J. R.
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Introduction: Pesticide exposure has been associated with poorer mental health, yet little is known about whether seasonal fluctuations in agricultural pesticide use are associated with cyclical changes in mood among people living in agricultural communities. We evaluated associations between 10 peak and off-peak pesticide spray seasons and ecological momentary assessment (EMA)-derived mood in a floricultural region in Ecuador. Methods: 496 participants completed repeated EMA surveys across 10 assessment administrations over 2.5 years (2022-2024), including one single-assessment administration and nine 10-day bursts (Nobservations=14,332). Mood outcomes included negative affect (sadness, anxiety, stress, anger, tiredness, difficulty concentrating; overall mean=2.79, Standard Deviation [SD]=1.32), positive affect (happiness, motivation; overall mean=4.21, SD=1.60), and behavioral dysregulation (aggression and impulsivity, overall mean=1.86, SD=1.29). Generalized linear mixed models estimated pooled, between-person and within-person associations between peak pesticide spray seasons and mood, adjusting for demographic and longitudinal factors Effect modification by sex, floricultural occupation, and cohabitation with a floricultural worker was assessed. Results: Peak spray seasons were associated with higher negative affect ({beta}=0.11 [0.06, 0.16]) and behavioral dysregulation ({beta}=0.10 [0.05, 0.15]) but not positive affect ({beta}=0.01 [-0.05, 0.07]). Associations were driven by within-person changes. Sex modified associations with negative affect, which were stronger in males than females. Floricultural occupation modified associations, with poorer mood, greater behavioral dysregulation and lower positive affect among floricultural workers than non-workers. Discussion: Peak pesticide spray seasons were associated with worsening of negative affect and behavioral dysregulation. EMA may provide a sensitive approach for detecting short-term neurobehavioral changes associated with seasonal pesticide exposure.
Hoque, S. M. A. U.; Islam, M. K.; Hasan, M. K.; Rahman, M. A.; Quaish, S. M.; Banu, B.; Hossain, Z. Z.; Baset, K. u.
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Background: In coastal Bangladesh, saline drinking water has been linked to raised blood pressure. The 2025 Multiple Indicator Cluster Survey (MICS) measured electrical conductivity (EC), a salinity indicator, in source water, but its report gave no population counts or district estimates. Objectives: To estimate how many people live in households whose tested source has high EC, and to describe patterns by place, household characteristics, source type and arsenic. Methods. EC was measured in source water of 6,040 households in 64 districts, February to June. In 14.5% of households the tested source was not the main drinking-water source. Primary outcomes were EC above 1,500 and 3,000 microsiemen/cm, survey risk classes that are not health-based standards. Estimates were survey weighted; comparisons were observational. Results: EC exceeded 1,500 microsiemen/cm in 5.3% of households (95% CI 4.7 to 5.9), about 9.0 million people, including 1.8 million above 3,000 microsiemen/cm. Coastal-zone districts held 26% of households but 70% of those above 1,500 microsiemen/cm. Shares varied little by wealth or in households with young children or pregnant women. Nationally, deep tube wells more often had high EC because most are coastal. In the coastal zone, deep and shallow wells had similar shares (16.1% and 17.9%). After district adjustment, EC was about 18% lower in deep wells (geometric mean ratio 0.82, 0.73 to 0.92). Within upazilas (restricted sample) it was 0.93 (0.80 to 1.07). Arsenic above 10 ppb was more common where EC was high, but this link weakened after district adjustment. Conclusions: Millions of people live in households whose tested source has high EC, mostly in coastal and south-central districts. Deep wells had modestly lower EC after geographic adjustment, but the difference shrank within upazilas and depended on the handling of implausibly low readings. The findings support measuring EC alongside arsenic, with documented meter calibration.
Khan, D.; Kwambana-Adams, B.; Tientcheu, P. E.; Thomas, S. A.; Ndow, P. S.; Kinteh, M.-A.; Worwui, A.; Mohammed, N. I.; Nicol, M. P.; Antonio, M.
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Abstract Background Air pollution contributes substantially to morbidity and mortality in low-income countries, where reliance on solid fuels leads to high levels of household exposure. Colonisation of the upper respiratory tract by Streptococcus pneumoniae is a prerequisite for pneumococcal disease, and inhaled air pollutants may influence colonisation through impaired mucociliary clearance. Therefore, we investigated the association between S. pneumoniae colonisation and personal exposure to particulate matter (PM2.5) and carbon monoxide (CO) as well as temperature and relative humidity in older children in The Gambia. Methods We conducted a prospective study of 134 children aged 5-14 years across eight visits in rural Gambia. Personal 24-hour PM2.5, CO, temperature and relative humidity exposures were measured using personal monitors. Concurrently, combined nasopharyngeal/oropharyngeal swabs were collected at each visit, and S. pneumoniae colonisation was determined by microbiological culture. Mixed-effects logistic regression models were used to examine associations between environmental exposures and colonisation. Exposures were additionally decomposed into between-child and within-child components. Models were adjusted for age, season, and household income tertile. Results A total of 554 child visits with paired exposure and microbiological data were analysed. Overall, 24-hour geometric mean PM2.5 and CO were 12.6 {micro}g/m3 (95% CI 12.2-13.1) and 0.16 ppm (95% CI 0.14-0.19) respectively and overall S. pneumoniae colonisation prevalence was 39.7%. In conventional models, PM2.5, CO, temperature, and relative humidity were not significantly associated with S. pneumoniae colonisation after adjustment for confounders. In the within-between decomposition analysis, higher between-child temperature exposure was consistently associated with lower odds of colonisation (mutually adjusted model: OR 0.74, 95% CI 0.56-0.98; p = 0.034). Relative humidity showed an inverse within-child association in crude analysis (OR 0.70, 95% CI 0.52-0.93; p = 0.013), which attenuated after adjustment for season and other confounders. No associations were observed for PM2.5 or CO exposures. Conclusion At the exposure levels observed in this cohort of older children, PM2.5 and CO exposures were not independently associated with S. pneumoniae colonisation. The pattern observed for temperature suggests that longer-term temperature conditions may be more relevant to pneumococcal colonisation than short-term exposure variation in this setting.
Parvin, S.; Rashid, M. O.; Rahman, M. M.; Zaber, A. A.; Hossain, M. B.; Begum, R.; Haque, M. A.
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Bangladesh's agricultural sector remains heavily dependent on pesticides and chemical inputs, yet limited attention has been paid to how farmers' knowledge of occupational health and environmental sustainability translates into actual practice across the full agricultural value chain. This study aimed to assess the knowledge and practices of farmers in Pabna District, Bangladesh, regarding occupational health, pesticide handling, environmentally sustainable farming, and market sanitation. A cross-sectional survey was conducted among 301 farmers in 2024 using a structured questionnaire covering socio-demographic characteristics, sustainable farming knowledge and adoption, soil testing and organic farming practices, pesticide handling and occupational health and safety behaviours, post-harvest waste management, and market sanitation conditions. Data were analysed using descriptive statistics. The majority of respondents were male (87.04%) and had no formal education (63.46%). Although most farmers reported knowledge of environmentally sustainable farming practices (97.70%) and pesticide label instructions (98.00%), corresponding safety practices were poor: only 10.63% reported wearing any personal protective equipment and 1.33% reported using a mask during pesticide application. Eye irritation was the most commonly self-reported health symptom following pesticide exposure (92.69%). Market sanitation infrastructure was similarly inadequate, with 89.00% of respondents reporting an absence of sanitary toilets. These findings indicate a consistent gap between farmers' knowledge and their actual practices across multiple domains of the agri-food system. Strengthening extension services, delivering practical hands-on occupational safety training, and investing in market sanitation infrastructure are recommended to close this gap and support safer, more sustainable farming practices in Bangladesh.
Guo, T.; Zhao, Y.; Wang, S.; Shen, C.; Jiang, Q.
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Objective: Environmental pollutants are increasingly recognized as potential risk factors for metabolic dysfunction-associated steatotic liver disease (MASLD), yet the effects of mixed exposures and underlying mechanisms remain unclear. We evaluated associations between environmental chemical mixtures and MASLD and the mediating role of inflammation-related biomarkers. Methods: We analyzed 60 environmental chemicals across six categories among 39,061 U.S. adults from the National Health and Nutrition Examination Survey (NHANES) 1999-2020. Principal Component Pursuit with Principal Component Analysis (PCP-PCA) identified latent exposure patterns. MASLD was identified using multisociety Delphi consensus criteria and the Hepatic Steatosis Index (HSI [≥] 36). Logistic regression, restricted cubic spline models, and mediation analysis were applied. Results: PCP-PCA generated 5-17 dimensions per chemical category, with first-dimension variance contributions ranging from 30.70% to 98.88%. Six dimensions from four categories were retained, with phthalate esters (PAEs) and organophosphate flame retardants (OPFRs) showing the most consistent associations with MASLD. PAEs Dim.1, explaining 90.71% of variance, showed a significant non-linear dose-response association (P-nonlinear = 0.0001). Significant associations were identified for mono-isobutyl phthalate (MiBP; OR 1.12, 95% CI 1.07-1.19), mono(carboxyoctyl) phthalate (MCOP; OR 1.08, 95% CI 1.02-1.14), mono(carboxynonyl) phthalate (MCNP; OR 1.12, 95% CI 1.03-1.21), and bis(1,3-dichloro-2-propyl) phosphate (BDCP; OR 1.15, 95% CI 1.08-1.23). C-reactive protein (CRP) and red cell distribution width (RDW) were the primary mediators, accounting for 32.42% and 19.62% of the MiBP-MASLD association, respectively (both p < 0.0001). Conclusion: Environmental co-exposure, particularly to PAEs and OPFRs, was associated with higher MASLD risk, with systemic inflammation potentially contributing to these associations.
Abanni, S. I.; Adache, C.; Ekure, B. M.; Omotosho, J.
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ObjectivesTo estimate the prevalence of objective peripheral neuropathy, and to test whether self-reported use of personal protective equipment (PPE) is associated with lower neuropathy risk, among adults attending a community hospital in a Nigerian population exposed to both agrochemicals and mining. DesignClinic-based cross-sectional study (June-November 2025), reported per STROBE. SettingInfant Jesus Community Hospital, Ishiagu, Ebonyi State, a community combining smallholder farming with granite and lead-zinc mining. Participants285 adults ([≥]18 years) attending the outpatient screening department; people with known diabetes were excluded. Main outcome measuresPeripheral neuropathy on the Michigan Neuropathy Screening Instrument (MNSI) examination -- an instrument validated in diabetic populations -- defined a priori as an abnormal 10 g monofilament test or absent/reduced ankle reflexes; three alternative case definitions were pre-specified. PPE use was scored 0-12. Associations were estimated by multivariable logistic regression adjusted for age and sex. ResultsThe proportion screening positive was 47.0% (95% CI 41.2-52.8) under the primary definition and ranged from 29.8% to 56.8% across definitions. PPE use was near-absent (89.1% never used gloves; 43.2% used none) and showed no detectable protective association (adjusted OR 0.97 per point, 95% CI 0.88-1.06). Men used PPE more than twice as often as women (55.1% vs 24.5%, p<0.001), yet neuropathy did not differ by sex (41.6% vs 49.5%, p=0.27). Only age was associated with neuropathy (adjusted OR 1.02 per year, p=0.02). ConclusionsNearly half of the adults sampled screened positive for peripheral neuropathy, and protective equipment showed no detectable protective association. Because PPE use was near-absent, the study cannot separate ineffective protection from too little protection to measure, and the cross-sectional design precludes causal inference. The equal burden across sexes despite markedly unequal protective behaviour is consistent with community-wide environmental exposure; reducing the total toxic load is a plausible priority that direct exposure measurement should now test.
Acuna, N.; Ortiz, J.; Rosario, N. E.; George, S. S.; Gonzalez, S.; Carrasquillo, O.; Domenech, L. T.; Ortiz, A.; Coredor-Cardona, N.; Cruz, L. A.; Ramos, S. R.; Silva, M. G.; Rodriguez, J. A.; Kumar, N.
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Background: Guanica, Puerto Rico, has one of the highest concentrations of environmental polychlorinated biphenyls (PCBs). This PCB contamination coupled with persistent poverty, population loss, and repeated environmental disasters has taken a heavier toll on Guanica community. Our environmental sampling has documented high levels of PCBs in sediment, air and fish, but far less is known about how residents themselves understand exposure, interpret health risk, and weigh contamination against the other pressures of daily life. Methods: We used a qualitative descriptive design nested within the larger HELP Study. This paper presents the final analysis of all qualitative data collected in Guanica: ten sessions comprising five focus groups and five interviews with fishermen (N = 31), conducted between November 2024 and October 2025 in familiar community settings. Sessions followed a semi-structured guide translated from English to Spanish and back-translated for accuracy. Recordings were transcribed in Spanish, verified against the audio, and analyzed in NVivo using codebook-style thematic analysis; three bilingual researchers coded collaboratively and resolved disagreements by consensus. Results: Five themes emerged from our analysis concerning how residents and fishermen understand and navigate PCB contamination: (1) perceived community decline shapes how residents prioritize environmental risks; (2) limited knowledge, misinformation, and communication gaps affect understanding of PCB contamination; (3) cancer concerns are high, but links to PCB exposure remain unclear; (4) PCB contamination is seen as a threat to livelihoods, especially fishing and tourism; and (5) deep mistrust and a desire for accountability influence perceptions of environmental interventions. Participants described contamination not as an isolated hazard but as one strand of a longer history of economic decline, disaster, and institutional neglect. Conclusions: Social, economic, and environmental conditions together shape how Guanica residents perceive contamination of their environment. Meaningful progress requires sustained community involvement, support for local initiatives, development of a Community Health Worker program, and expanded partnerships with local institutions and schools to close communication gaps and promote long-term resilience to address the health effects of PCB contamination in Guanica.
Hilliard, R. F.; McDonald, E.; Charbonneau, L.; Oliver-Olsen, C.; Fernandez Snell, A. M.; Garretson, A. C.; Disney, J. E.
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Per- and polyfluoroalkyl substances (PFAS) are present throughout the environment due to decades of use in many commercial products and industrial processes. These molecules contain a hydrophobic fluorocarbon tail and a functional headgroup (typically a carboxylic or sulfonic acid) that allows hydrophilic interactions with the surrounding environment. These properties make them inherently resistant to degradation, difficult to track through the environment, readily bioaccumulative, and likely to impact human health. Through collaboration with town officials, multiple meetings with local sustainability committee members and school officials, and direct contact with individual homeowners, we conducted community-driven sampling of PFAS in well water from 105 houses in Tremont, ME, a rural coastal town that relies on private wells for drinking water. The rate of PFAS detection for one or more analytes across all wells (N=105) was 69%. Of all wells tested, 16 (15%) exceeded the current public drinking water standard in Maine (20 ng/L for 6 PFAS), and an additional 17 (totaling 31% of all wells tested) exceeded Maine's newly adopted public drinking water standards for the state (based on EPA 2024 standards). Because private wells are unregulated, homeowners may use these results as a guide for taking action to maintain safe drinking water. Both hierarchical cluster analyses and pairwise Spearman's rank correlation of PFAS test results revealed similar profiles in households near and far from one another. Along with the absence of obvious, large-scale potential point sources of PFAS contamination, these findings support septic systems as the primary source of PFAS contamination in drinking water across this town. The community-driven approach to the sampling effort has enabled information sharing on the importance of water filtration options, discussion of long-term pollution abatement strategies for individual households and the town, and focused efforts for future well water testing and PFAS mitigation.
Bashar, S. J. J.; Al Fidah, M. F.; Islam, M. R.; Roy, A. K.; Raqib, R.; Ahmed, T.; Mahfuz, M.
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Background: Lead is a cumulative environmental toxicant for which no safe level of exposure has been identified, and pregnant women and their fetuses are particularly vulnerable because lead readily crosses the placenta and can be mobilised from maternal bone stores. Bangladesh conducted its first nationally representative blood lead testing among pregnant women through the 2025 Multiple Indicator Cluster Survey (MICS), but a detailed, multi-domain analysis of the determinants of elevated blood lead level (BLL) among this population has not yet been reported. Methods: We conducted a secondary cross-sectional analysis of 1,928 pregnant women aged 15-49 years with complete data from the women's dataset of Bangladesh MICS 2025. Elevated BLL was defined as [≥]5 g/dL. Survey-weighted logistic regression was used to estimate unadjusted and adjusted odds ratios (aOR) for co-exposure to arsenic, cadmium and mercury and sociodemographic and socioeconomic covariates. Slope Index of Inequality (SII) as well as Relative Index of Inequality (RII) were used to quantify wealth-related inequality. Population attributable fractions (PAF) were estimated for three counterfactual scenarios, and adaptive least absolute shrinkage and selection operator (LASSO) regression was used as a sensitivity analysis. Results: Elevated BLL was present among 6.2% of participants. In the adjusted model, a 2-fold rise in blood cadmium was associated with higher odds of elevated BLL (aOR: 1.54; 95% CI: 1.21-1.96), whereas a 2-fold rise in blood mercury (aOR: 0.63; 95% CI: 0.48-0.83), rural residence (aOR: 0.55; 95% CI: 0.32-0.94), secondary education (aOR: 0.49; 95% CI: 0.28-0.85) and post-secondary education (aOR: 0.22; 95% CI: 0.11-0.46) were associated with lower odds. Belonging to progressively wealthier quintiles was associated with markedly higher odds, BLL rising to an aOR of 10.32 (95% CI: 4.41-24.15) for the richest versus poorest quintile. The RII was 8.59 (95% CI: 4.24-17.40) and the SII was 0.159 (95% CI: 0.101-0.218), indicating a substantial pro-rich gradient in elevated BLL. Counterfactual scenarios suggested that shifting the population to secondary-level education could reduce the prevalence of elevated BLL by 52.9% (95% CI: 20.6-72.0) and shifting to rural residence by 24.3% (95% CI: 1.4-41.9). Adaptive LASSO variable selection produced estimates consistent in direction and magnitude with the fully adjusted model. Conclusion: In this national sample, approximately one out of every 16 pregnant women had blood lead levels that met or exceeded the action threshold set by the World Health Organization, with this issue being particularly prevalent among wealthier, urban, and less-educated women, and was compounded by co-exposure to cadmium. In Bangladesh, the typical pattern observed for maternal and child health indicators does not align with the inverse relationship found between household wealth and lead exposure. This suggests that the sources of exposure are not merely indicators of material poverty. Antenatal blood lead screening, source investigation, and equity-informed lead-reduction strategies that specifically reach wealthier and urban households are warranted.
Kalam, M. A.; Sinharoy, S. S.; Steenland, K.; Thompson, L. M.; Diaz-Artiga, A.; McCracken, J. P.; Balakrishnan, K.; Aravindalochanan, V.; Garg, S.; Rosa, G.; Ndagijimana, F.; Jabbarzadeh, S.; Johnson, M.; Pillarisetti, A.; Kearns, K.; Lovvorn, A. E.; Ramakrishnan, U.; Peel, J.; Clasen, T. F.
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Objective Reducing household air pollution exposure during gestation and infancy may have longer-term benefits for child linear growth. We examined whether a liquefied petroleum gas (LPG) cookstove and fuel intervention delivered during gestation and infancy could improve height-for-age Z scores (HAZ) and reduce the risk of stunting at ages 2-5 years in India, Rwanda, and Guatemala. Materials and method The Household Air Pollution Intervention Network (HAPIN) was a randomized controlled trial that enrolled ~3200 pregnant women across Guatemala, India, Peru, and Rwanda. Women in the intervention group received an LPG cookstove and free fuel during pregnancy and until the infant reached 12 months of age. Following the HAPIN trial, we continued following children in Guatemala, India, and Rwanda (N=2169) and measured child height at ages 2, 3, 4, and 5 years (HAPIN 2.0). As prespecified in the study protocol, we used mixed-effects models, as well as linear and log-binomial regression, within the intention to treat (ITT) framework, to evaluate the interventions effect on HAZ and stunting. Subgroup analyses were performed to assess effect modification by child sex, maternal height, and intervention country. Results The intervention reduced gestational exposures to particulate matter (PM2.5: 80.7 vs 117.5 {micro}g/m3), carbon monoxide (CO: 1.3 vs 2.0 ppm), and black carbon (BC: 8.6 vs 12.1 {micro}g/m3) and infancy exposures (PM2.5: 36.9 vs 113.2 {micro}g/m3; CO: 0.60 vs 2.2 ppm). Post-trial PM2.5 exposure were similar between arms: 99.9 vs 98.7 {micro}g/m3. We found no statistically significant effect of the intervention on repeated measures of HAZ ({beta} = -0.06, 95% CI: -0.16, 0.03 p=0.204), annual HAZ, stunting, nor severe stunting at any age during the follow-up. There was no statistically significant effect modification by subgroups. Conclusion Despite substantial reductions in air pollution exposures during the trial, the LPG intervention did not improve growth or reduce stunting risk from ages 2 through 5 years in this multi-country cohort. These findings, consistent with prior results of the lack of effects on growth through 12 months, provide additional evidence that a clean cooking intervention alone may not be sufficient to address childhood stunting in low-resource settings. Future exposure-response analyses will supplement these ITT analyses.
Parker, E.; Oladipo, F.; Levy, J. I.; Ope-Ewe, O. O.; Soumare, H.; Andersen, K.; Happi, A. N.; Happi, C. T.
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Population-scale pathogen surveillance is limited worldwide, particularly in resource-constrained settings, where clinical systems only monitor select priority pathogens and reach only those who can access healthcare. Wastewater-based epidemiology addresses many of these gaps, offering cost-effective surveillance that is adaptable across diverse implementation contexts. In Lagos, Nigeria, a high enteric pathogen burden coincides with a complex sanitation landscape. However, circulating pathogen diversity in Lagos is largely uncharacterised outside of outbreak contexts. Here we characterize human-associated pathogen diversity in Lagos with virus-enriched metagenomic and metatranscriptomic sequencing of untreated wastewater sampled from open drainage canals from July-August 2024. We detected a diverse human-associated virome dominated by enteric adenoviruses, astroviruses and caliciviruses. We recovered numerous partial and near-complete genomes from pathogens of public health concern, including noroviruses, enteroviruses and sapoviruses. Although our enrichment targeted viruses, we detected diverse bacterial pathogens, including recurrent detection of Vibrio cholerae, other enteric bacteria, and zoonotic pathogens such as Streptococcus suis. We also detected antimicrobial resistance genes, including aminoglycoside, beta-lactam and fluoroquinolone resistance and clinically important genes such as mcr. Together, these results establish a regional baseline of pathogen diversity and demonstrate the utility of virus-enriched sequencing for integrated wastewater surveillance.
Riedmann, U.; Stevenson, A. C.; Dibben, C.; Grant, W. B.; Sprenger, M.; Zgaga, L.; Woltsche, J.; Wolf, P.; Maerz, W.; Ioannidis, J.; Pilz, S.
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Background: Previous studies indicated that regional fluctuations in COVID-19 impact were associated with socioeconomic, demographic and environmental factors early in the pandemic. It is unclear whether factors associated with regional COVID-19 mortality and SARS-CoV-2 infections changed over the course of the pandemic. Methods: We evaluated the association of ecological factors with municipality-specific COVID-19 mortality in the national population of Austria between January 2020 and June 2023. Analyses were conducted separately per calendar year and pooled across years via random-effects meta-analysis. Outcomes were analysed using univariable and multivariable zero-inflated negative binomial (ZINB) regression, including annually averaged environmental exposome exposure (including air pollution and UV radiation), socioeconomic, demographic and infection dissemination predictors with significance threshold set to p<0.005. Secondary analysis modelled SARS-CoV-2 infections using of negative-binomial model (NB). Two additional approaches for smaller predictor set selection were applied as sensitivity analyses. Results: Within the entire observation period 18,430 COVID-19 deaths were reported. In univariable analyses (pooled RR (99.5% CI)), COVID-19 mortality was significantly associated with the proportion of commuters (0.79 (0.73-0.86)), residents aged 75-84 (1.18 (1.01-1.37)) and [≥]85 years (1.29 (1.04-1.60)), residents with at most compulsory education (1.15 (1.02-1.29)), employed residents aged 15-64 (0.89 (0.85-0.93)), and homeowners (0.91 (0.83-0.99)), as well as with precipitation (0.94 (0.89-0.99)) and the average time with a mean temperature of 5-15 C (0.95 (0.90-0.99)). In multivariable analyses the share of population aged 85 or older (1.30 (1.09-1.54)) and home ownership (0.92 (0.87-0.98)) were independently significant. Mortality predictor estimates were relatively stable across pandemic years. Across 5,963,882 documented SARS-CoV-2 infections share of employed in 15- to 64-year-olds (1.01 (1.01-1.02)), part-time employment rate (1.01 (1.00-1.02)) and district level nursing care allowance recipiency (0.97 (0.95-0.98)) were associated with detected infections. Overnight stays, population 85 or older, income, compulsory education or less and air pollution all had multiple significant estimates with opposite directionality, leading to non-significant overall associations. Sensitivity analyses outcomes mirrored main analyses outcomes. Conclusions: Throughout the pandemic in Austria, demographic and socioeconomic factors were associated with COVID-19 mortality and infections, but many associations, especially for infections, were unstable over time. These findings underscore the importance of structural vulnerabilities in epidemic impact.
Bloomberg, M.; Jones, M.; Brocklebank, L.; Zaninotto, P.; Steptoe, A.
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Background Staying physically active is essential for healthy ageing. Exposure to high levels of air pollutants such as particulate matter (PM) is associated with less active, more sedentary lifestyles in older adults. Whether results extend to typical fluctuations in daily PM exposure is unclear. We examined associations of higher-than-usual personal exposure to PM (PM2.5 and PM10) with next-day movement behaviour in older adults, assessed using concurrently worn personal air quality monitors and accelerometers. Methods The present study used 304 days of data from 67 adults aged 50-85 years living in the UK. For five days, participants wore accelerometers 24-hours per day and personal air quality monitors during waking hours. Average daily time spent in movement behaviours (moderate-to-vigorous physical activity [MVPA], light physical activity [LPA], sedentary behaviour [SB]) and step count was extracted from accelerometers, and average daily exposure to PM2.5 from personal air quality monitors. PM10 was examined in secondary exploratory analyses. We used linear mixed models to examine within-person associations of deviation from usual PM exposure with next-day movement outcomes, with estimates presented for 'usual' (individual mean) and 'higher-than-usual' (+1 interquartile range, equivalent to 2.6 g/m3 beyond individual mean PM2.5 exposure and 2.8 g/m3 beyond individual mean PM10 exposure) exposure. Analyses were repeated using area-based PM estimates. Results Compared with usual exposure, higher-than-usual PM2.5 was associated with 8 minutes less LPA (95% CI=-14 to -2) and 483 fewer steps (-855 to -82) on the following day. Exposure to higher than usual PM10 was associated with 8 minutes less LPA (-13 to -3), 8 minutes more SB (0 to 15), and 412 fewer steps (-739 to -85) on the following day. There was no association with MVPA, and no associations when area-level PM estimates were used as opposed to estimates from personal air quality monitors. Conclusions Typical daily variability in PM exposure in a setting with relatively low overall PM levels was associated with modest next-day differences in movement behaviour in older adults. Higher-than-usual PM exposure was associated with less next-day activity and more sedentary time. Personal monitoring may be important for capturing short-term exposure-behaviour associations. Trial registration N/A
Hossain, S. T.
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Background: Childhood lead exposure is a major global health concern. The 2025 Bangladesh Multiple Indicator Cluster Survey (MICS7) measured blood lead in a nationally representative sample of children aged 12-59 months for the first time. Preliminary reports suggested elevated blood lead was more common in wealthier urban households, contrary to the usual assumption. Methods: We analysed 10,622 children with a valid blood lead result (10,458 with complete covariate data for regression models). Elevated blood lead was defined as >=5 ug/dL. Prevalences are survey-weighted with design-based confidence intervals. Associations were estimated with survey-weighted logistic regression using stratified-cluster (Taylor-linearised) variance, and checked with a stratified bootstrap of primary sampling units and Benjamini-Hochberg false-discovery-rate control. Sensitivity analyses varied the outcome definition, the sample, and the weighting. Results: Survey-weighted prevalence of elevated blood lead was 38.5% (95% confidence interval [CI] 37.2-39.9%). Prevalence rose monotonically from 30.2% in the poorest to 51.9% in the richest wealth quintile. In the fully adjusted model, each wealth quintile was associated with 23% higher odds (adjusted odds ratio [AOR] 1.23, 95% CI 1.16-1.30), each level of maternal education with 20% lower odds (AOR 0.80, 95% CI 0.76-0.84), and urban residence with 37% higher odds (AOR 1.37, 95% CI 1.18-1.59). Household crowding was associated with higher odds (AOR 1.17 per person per room, 95% CI 1.10-1.24). The wealth-education interaction had AOR 0.95 (95% CI 0.92-0.98). In an exploratory contrast, weighted prevalence was 76.2% among children in the richest quintile with mothers having at most primary education versus 19.5% among those in the poorest quintile with mothers having higher secondary or tertiary education (prevalence ratio 3.9, 95% CI 2.6-6.0). Adjusted odds relative to Barishal ranged from 0.39 in Rajshahi to 3.29 in Dhaka. Conclusions: In this cross-sectional survey, elevated blood lead was more prevalent among wealthier and urban households and among children of less educated mothers, with large geographic variation. Lead prevention and source-identification efforts should therefore not be restricted to poor communities; prevalence remained high even in the poorest quintile. Interpretation is limited by substantial missing blood lead results and coding uncertainty.
Pandey, S.; Olivetti, L.; Walter, I. J.; Brizzi, L. F.; Ramusino, F. C.; Hardelid, P.; Döring, S.; Carlo, T.; Mazzoleni, M.; Magnusson, C.; Messori, G.; Raffetti, E.
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Background Short-term weather conditions can trigger paediatric hospital admissions, but evidence remains limited on the health relevance of intraday temperature variability, humidity, and precipitation, and generally on which subgroups are most susceptible. Methods We conducted a nationwide case time-series study of Swedish children and adolescents aged 6-18 years using linked register data. Associations between daily mean temperature, intraday temperature variability, relative humidity, and precipitation and inpatient hospitalisations were estimated with Poisson regression (individual fixed effects) combined with distributed lag non-linear models over lags 0-21 days. Outcomes included all-cause hospitalisation and cause-specific admissions. Effect modification was examined by sex, age group, socioeconomic indicators, region, and calendar periods. Findings Among 4,638,247 children and adolescents in the cohort, 1,070,702 (23.1%) experienced at least one inpatient hospitalisation, contributing 1,736,169 hospitalisation events. All-cause hospitalisation increased with higher mean temperature, with risk highest at hot extremes. Intraday temperature variability showed a U-shaped association, with higher rates at both lowest and highest exposure levels. Relative humidity showed no association with hospitalisation risk. Higher precipitation was associated with increased hospitalisation risk, but estimates at high rainfall levels were imprecise. Stratified analyses indicated modest differences by sex and socioeconomic indicators, but clearer heterogeneity by age and region, with the highest risks among younger children and in East Sweden; associations varied across calendar periods and were imprecise for most cause-specific outcomes. Sensitivity analyses mostly showed that the main curve shapes were robust. Interpretation Short-term exposure to hot temperatures, both low and high intraday temperature variability, and higher levels of precipitation were associated with an increased risk of all-cause hospitalisation among children in Sweden, with clearer variation by age group and region than by sex or socioeconomic position. These findings support targeting paediatric climate-health preparedness and early-warning systems toward younger children and higher-risk regions such as eastern Sweden and extending such systems beyond mean temperature to include intraday temperature variability, a distinct, currently overlooked driver of risk that heat-focused systems are not designed to capture. Fundings This research was funded by Formas the Swedish Research Council for Sustainable Development (grant no. 2023-01774 and 2022-01845) and the Swedish Research Council (2025-02804 and 2022-06599).
Hasan, M. K.; Hossain, F. S.; Islam, M. K.; Sultana, A.; Rahman, M. A.; Quaish, S. M.; Naher, T.; Sharif, M. M.; Hoque, S. M. A. U.
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Background. Lead crosses the placenta and harms the developing brain, and no safe level is known. Bangladesh lacks national estimates of lead exposure in pregnancy. Objectives. We estimated blood lead in pregnant women nationally, described where and in whom it was raised, and examined links with child lead and haemoglobin. Methods. In the Bangladesh Multiple Indicator Cluster Survey 2025, 1,932 of 2,711 eligible pregnant women (71%) had valid venous blood results. Survey-weighted modified Poisson models estimated prevalence ratios (PR) for blood lead of 3.5 microgram/dL or more, an analytical cut-off. We also studied 540 households with a tested child aged 12 to 59 months. Results. Among tested women, geometric mean blood lead was 2.05 microgram/dL (95% CI 1.99 to 2.12). In all, 17.7% (15.7 to 19.9) had 3.5 microgram/dL or more and 7.6% (6.1 to 9.3) had 5 microgram/dL or more. Greater Dhaka, defined after inspecting district estimates, held 12% of pregnant women but 64% (54 to 73) of those at 5 microgram/dL or more. The richest quintile had a crude PR of 3.06 (2.02 to 4.63, P<0.001), attenuated to 1.09 (0.72 to 1.67, P=0.678) after adjustment for place. No clear association was seen with cosmetics, indoor smoking or nearby battery sites. A woman's lead of 3.5 microgram/dL or more was associated with child lead of 5 microgram/dL or more (adjusted PR 1.50, 1.16 to 1.96, P=0.002). This cut-off identified only 23% (16 to 30) of them. Conclusions. Raised blood lead in pregnancy varied sharply by place and was highest in greater Dhaka. The crude wealth association was markedly attenuated after adjustment for place. Maternal lead was linked with child lead, but most exposed children lived with women below the cut-off. These findings support source investigation in greater Dhaka and evaluation of targeted lead assessment for women and children.
Gueltzow, M.; Benmarhnia, T.; Ebeling, M.; Irrgang, C.
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Background: Multiple factors can drive heat susceptibility, but are typically analyzed individually. This study investigates high-dimensional heterogeneity across multiple domains in the effect of hot days on emergency hospitalizations across German districts. Methods: We obtained emergency hospitalization rates per 1,000 in 3-day windows for the summers of 2005-2023 from the German Diagnosis-Related Groups-Statistic, linked with spatio-temporal temperature information. A hot day was defined as at least one day above the district-level 98th percentile heat index. Multiple characteristics of the demographic, health/social, and environmental domains were selected as potential effect modifiers. We implemented a generalized random forest, where outcome and propensity scores were modeled with fixed effects estimators to control for seasonality and district-level confounding. We divided the conditional average treatment effects (CATE) into quartiles to map their spatial distribution and identify key effect modifiers via the variable importance and observed indicator profiles across quartiles. Results: We found substantial variation across districts regarding heat-related emergency hospitalizations. The top three indicators for predicting this effect heterogeneity were the percentage of people seeking protection, population below age 6, and air pollution levels. The observed indicator profile for the most susceptible districts was characterized by a larger percentage of vulnerable populations, higher car density, and fewer hospital beds. Conclusion: There is substantial variation in heat susceptibility across and within districts in Germany. We propose an approach that can help understanding such complex interplay of indicators from different domains driving heterogeneity.
Madson, E.; Kapanka, A.; Kwamutakha, S.; Ouma, C.; Sinik, M.; Okoth, B.; Agira, J.; Amondi, C.; Simiyu, S.; Gutema, F.; Sewell, D.; Baker, K.
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This study developed a streamlined, sensitive and rapid method for co-detection of low concentrations of Salmonella enterica, Shigella flexneri, Listeria monocytogenes, and pathogenic Escherichia coli from soil. First, autoclaved soil from Iowa with serial dilutions of bacteria to confirm individual species recovery rates on selective agar by qPCR under varying primary enrichment times was used. All pathogens were detected by qPCR of colonies recovered from replicate sterile soils spiked with 10^1 or greater bacteria within 5 hours of enrichment. Shiga toxin expressing E. coli (STEC) and L. monocytogenes were consistently co-recovered in autoclaved and natural soil, pathogen spiking concentration, and secondary enrichment time. S.enterica was consistently recovered at autoclaved and natural concentrations, while S. flexneri detection rates fluctuated. Twenty-three soil samples from Kenyan neighborhoods, with prior evidence of contamination, was compared to qPCR detection at each protocol stage: processing, primary enrichment, secondary enrichment, and selective colony isolation. Detection rates substantially increased for S. enterica, STEC and other pathogenic E. coli after enrichment, with optimal detection rates occurring after secondary enrichment. Testing colonies from selective agar resulted in high false negative rates, possibly reflecting competition from native soil microbiota that was absent in spiked sterile soil experiment. Evaluation of the method with other environmental sample types yielded consistent detection patterns. Evidence suggests a protocol including 24-hour primary enrichment, followed by 24-hour secondary enrichment, and qPCR testing of soil DNA at primary and secondary steps is a reproducible and more expedient method for co-detecting common Enterobacteriaceae and L. monocytogenes pathogens in soil.