Cancer incidence in Swedish oil refinery workers exposed to benzene.

BACKGROUND: Oil refinery workers are exposed to benzene, which is a well-known cause of leukaemia, but results on leukaemia in oil refinery workers have been mixed, and the data on workers' exposure is limited. Oil refinery workers are also exposed to asbestos and several studies have shown increased risk of mesothelioma. AIM: The objective was to investigate cancer incidence, especially leukaemia, at low to moderate exposure to benzene in an update of a previous study of employees at three Swedish oil refineries. METHODS: Cancer incidence was followed up in 2264 men (1548 refinery operators) employed at three oil refineries in Sweden for at least one year. Job types and employment times were collected from complete company files. A retrospective assessment of the benzene exposure was performed by occupational hygienists in collaboration with the refineries using historic measurements as well as detailed information on changes in the industrial hygiene and technological developments. Cases of cancer were retrieved by a linkage with the Swedish Cancer Register through 35-47 years of follow-up and standardized incidence ratios (SIR) with 95% confidence intervals (CI) were calculated. RESULTS: In total, 258 tumors had occurred versus 240 expected (SIR 1.07; 95% CI 0.95-1.21). There were 10 cases of leukaemia, all in refinery operators (SIR 2.4; 95% CI 1.18-4.51). There were three cases of pleural mesothelioma, two of which in refinery operators. The mean estimated cumulative benzene exposure for the cases of leukaemia was 7.9 ppm-years (median 4.9, range 0.1-31.1). DISCUSSION: The study suggests that low to moderate average cumulative benzene exposure increases the risk of leukaemia. Limitations include the modest number of cases and potential misclassification of exposure. CONCLUSION: The present study indicated an increased risk of leukaemia in male oil refinery workers with low to moderate exposure to benzene.

Scientific Committee guidance on appraising and integrating evidence from epidemiological studies for use in EFSA's scientific assessments.

EFSA requested its Scientific Committee to prepare a guidance document on appraising and integrating evidence from epidemiological studies for use in EFSA's scientific assessments. The guidance document provides an introduction to epidemiological studies and illustrates the typical biases, which may be present in different epidemiological study designs. It then describes key epidemiological concepts relevant for evidence appraisal. This includes brief explanations for measures of association, exposure assessment, statistical inference, systematic error and effect modification. The guidance then describes the concept of external validity and the principles of appraising epidemiological studies. The customisation of the study appraisal process is explained including tailoring of tools for assessing the risk of bias (RoB). Several examples of appraising experimental and observational studies using a RoB tool are annexed to the document to illustrate the application of the approach. The latter part of this guidance focuses on different steps of evidence integration, first within and then across different streams of evidence. With respect to risk characterisation, the guidance considers how evidence from human epidemiological studies can be used in dose-response modelling with several different options being presented. Finally, the guidance addresses the application of uncertainty factors in risk characterisation when using evidence from human epidemiological studies.

The concentrations and behavior of classic phthalates and emerging phthalate alternatives in different environmental matrices and their biological health risks.

Because of their excellent plasticity, phthalates or phthalic acid esters (PAEs) are widely used in plastic products. However, due to the recognized toxicity of PAEs and legislative requirements, the production and use of emerging PAE alternatives have rapidly grown, such as di-isononyl cyclohexane-1,2-dicarboxylate (DINCH) and di(2-ethylhexyl) terephthalate (DEHTP) which are the primary replacements for classic PAEs. Nowadays, PAEs and emerging PAE alternatives are frequently found in a variety of environmental media, including the atmosphere, sludge, rivers, and seawater/sediment. PAEs and emerging PAE alternatives are involved in endocrine-disrupting effects, and they affect the reproductive physiology of different species of fish and mammals. Therefore, their presence in the environment is of considerable concern due to their potential effects on ecosystem function and public health. Nevertheless, current research on the prevalence, destiny, and conduct of PAEs in the environment has primarily focused on classic PAEs, with little attention given to emerging PAE alternatives. The present article furnishes a synopsis of the physicochemical characteristics, occurrence, transport, fate, and adverse effects of both classic PAEs and emerging PAE alternatives on organisms in the ecosystem. Our analysis reveals that both classic PAEs and emerging PAE alternatives are widely distributed in all environmental media, with emerging PAE alternatives increasingly replacing classic PAEs. Various pathways can transform and degrade both classic PAEs and emerging PAE alternatives, and their own and related metabolites can have toxic effects on organisms. This research offers a more extensive comprehension of the health hazards associated with classic PAEs and emerging PAE alternatives.

Chronic exposure to drinking water nitrate and trihalomethanes in the French CONSTANCES cohort.

Trihalomethanes (THMs) and nitrate are widespread chemicals in drinking water. Chronic exposure has been associated with increased cancer risk despite inconclusive evidence, partly due to the challenges in long-term exposure assessment and potential exposure misclassification. We estimated concentrations of nitrate and THMs in drinking water using a public regulatory monitoring database (SISE-Eaux) for CONSTANCES, a French population-based prospective cohort. We obtained 26,322,366 measurements of drinking water parameters from 2000 to 2020. We excluded missing, implausible and duplicated measurements; we corrected or imputed missing geocodes of sampling locations; we calculated the annual median concentration of nitrate and THMs by surveillance area. To predict missing annual median concentrations, linear mixed models with random intercept using surveillance area as a clustering variable were developed for each region for nitrate and the four THM components (chloroform, chlorodibromomethane, bromodichloromethane and bromoform) separately. Concentrations in the nearest surveillance area from the household were merged per year among 75,462 participants with residential history geocoded for 2000-2020. Estimated concentrations resulting from this approach were compared with measured concentrations in 100 samples collected in Paris, Rennes and Saint-Brieuc in 2021. Median annual concentrations of total THMs and nitrate at study participants' homes for 2000-2020 were, respectively, 15.7 µg/l (IQR: 15.2) and 15.2 mg/l (IQR: 20.8). Among these, 35% were based on measurements for nitrate (16% for THMs), 44% (46%) were predicted using on linear mixed models, and 21% (38%) were based on distribution unit median values. Conditional R2 predictive models ranged from 0.71 to 0.91 (median: 0.85) for nitrate, and from 0.48 to 0.80 for THMs (median: 0.68). These concentrations will allow future association analyses with risk of breast and colorectal cancer. Our cleaning process introduced here could be adapted to other large drinking water monitoring data.

A comprehensive review of 5G NR RF-EMF exposure assessment technologies: fundamentals, advancements, challenges, niches, and implications.

This review offers a detailed examination of the current landscape of radio frequency (RF) electromagnetic field (EMF) assessment tools, ranging from spectrum analyzers and broadband field meters to area monitors and custom-built devices. The discussion encompasses both standardized and non-standardized measurement protocols, shedding light on the various methods employed in this domain. Furthermore, the review highlights the prevalent use of mobile apps for characterizing 5G-NR radio network data. A growing need for low-cost measurement devices is observed, commonly referred to as "sensors" or "sensor nodes," that are capable of enduring diverse environmental conditions. These sensors play a crucial role in both microenvironmental surveys and individual exposures, enabling stationary, mobile, and personal exposure assessments based on body-worn sensors, across wider geographical areas. This review revealed a notable need for cost-effective and long-lasting sensors, whether for individual exposure assessments, mobile (vehicle-integrated) measurements, or incorporation into distributed sensor networks. However, there is a lack of comprehensive information on existing custom-developed RF-EMF measurement tools, especially in terms of measuring uncertainty. Additionally, there is a need for real-time, fast-sampling solutions to understand the highly irregular temporal variations EMF distribution in next-generation networks. Given the diversity of tools and methods, a comprehensive comparison is crucial to determine the necessary statistical tools for aggregating the available measurement data.

Occupational exposure to chrysotile in an asbestos cement factory in Kyrgyzstan.

OBJECTIVES: An increasing number of countries are banning the production and use of asbestos, in compliance with the ratification of the C162 Asbestos Convention and the Basel Convention, and in response to the call for its elimination in the ILO resolution and WHO reports on the health risks associated with asbestos. Nevertheless, several countries, including Kyrgyzstan, are still miners and/or manufacturers of asbestos. The main objective of the study is to assess the occupational exposure to chrysotile of workers engaged in a production facility of asbestos-cement products in Kyrgyzstan. METHODS: Monitored workers (n = 16, for a total of n = 18 samples) were divided into 3 "Similar Exposure Groups" (SEGs; SEG-1: asbestos loading; SEG-2; asbestos-cement mixing; SEG-3: cutting of asbestos-cement sheets) according to EN 689 standard. Samples were collected through personal sampling and subsequently examined by means of scanning electron microscope equipped with an energy-dispersive spectrometer for the compositional analysis of each fibre. The numerical concentration of airborne asbestos fibres was henceforward determined by dividing the number of fibres and the volume of sampled air (expressed in the number of fibres per millilitre of air: ff/ml). RESULTS: Investigated workers resulted to be exposed to chrysotile fibres. Results (GM ± GSD) outlined extremely high exposure levels for SEG-1 (2.2 ± 2.1 ff/ml) and SEG-3 (4.7 ± 1.6 ff/ml) workers and lower-but still relevant-exposure values for SEG-2 (0.91 ± 2.6 ff/ml) workers. CONCLUSIONS: The results obtained in this case study can help to document potentially critical situations of occupational exposure to asbestos that can still occur nowadays in low and middle-income countries where asbestos is still mined and processed.

Estimating ambient air pollutant concentrations outside and inside homes in the Subpopulations and Intermediate outcomes in COPD air pollution (SPIROMICS air) cohort.

BACKGROUND: Valid, high-resolution estimates of population-level exposure to air pollutants are necessary for accurate estimation of the association between air pollution and the occurrence or exacerbation of adverse health outcomes such as Chronic Obstructive Pulmonary Disease (COPD). OBJECTIVES: We produced fine-scale individual-level estimates of ambient concentrations of multiple air pollutants (fine particulate matter [PM2.5], NOX, NO2, and O3) at residences of participants in the Subpopulations and Intermediate Outcomes in COPD Air Pollution (SPIROMICS Air) study, located in seven regions in the US. For PM2.5, we additionally integrated modeled estimates of particulate infiltration based on home characteristics and measured total indoor concentrations to provide comprehensive estimates of exposure levels. METHODS: To estimate ambient concentrations, we used a hierarchical high-resolution spatiotemporal model that integrates hundreds of geographic covariates and pollutant measurements from regulatory and study-specific monitors, including ones located at participant residences. We modeled infiltration efficiency based on data on house characteristics, home heating and cooling practices, indoor smoke and combustion sources, meteorological factors, and paired indoor-outdoor pollutant measurements, among other indicators. RESULTS: Cross-validated prediction accuracy (R2) for models of ambient concentrations was above 0.80 for most regions and pollutants. Particulate matter infiltration efficiency varied by region, from 0.51 in Winston-Salem to 0.72 in Los Angeles, and ambient-source particles constituted a substantial fraction of total indoor PM2.5. CONCLUSION: Leveraging well-validated fine-scale approaches for estimating outdoor, ambient-source indoor, and total indoor pollutant concentrations, we can provide comprehensive estimates of short and long-term exposure levels for cohorts undergoing follow-up in multiple different regions.

Evaluation of airborne asbestos concentrations associated with the maintenance of brakes on an industrial overhead crane.

OBJECTIVES: To evaluate potential airborne asbestos exposures during brake maintenance and repair activities on a P&H overhead crane, and during subsequent handling of the mechanic's clothing. METHODS: Personal (n = 27) and area (n = 61) airborne fiber concentrations were measured during brake tests, removal, hand sanding, compressed air use, removal and reattachment of chrysotile-containing brake linings, and reinstallation of the brake linings. The mechanic's clothing was used to measure potential exposure during clothes handling. RESULTS: All brake linings contained between 19.9% to 52.4% chrysotile asbestos. No amphibole fibers were detected in any bulk or airborne samples. The average full-shift airborne chrysotile concentration was 0.035 f/cc (PCM-equivalent asbestos-specific fibers, or PCME). Average task-based personal air samples collected during brake maintenance, sanding, compressed air use, and brake lining removal tasks ranged from 0 to 0.48 f/cc (PCME). The calculated 30-minute time-weighted average (TWA) airborne chrysotile concentration associated with 5-15 minutes of clothes handling was 0-0.035 f/cc PCME. CONCLUSION: The results indicated that personal and area TWA fiber concentrations measured during all crane brake maintenance and clothes handling tasks were below the current OSHA 8-h TWA Permissible Exposure Limit for asbestos of 0.1 f/cc. Further, no airborne asbestos fibers were measured during routine brake maintenance tasks following the manufacturer's maintenance manual procedures. All short-term airborne chrysotile concentrations measured during non-routine tasks were below the current 30-minute OSHA excursion limit for asbestos of 1 f/cc. This study adds to the available data regarding chrysotile exposure potential during maintenance on overhead cranes.

Can next generation ecological risk assessment decisions be made today?-A case study of regulatory risk assessment in the United States.

We examined the need for new in vivo avian toxicity testing for three common industrial chemicals (1,2 dichloropropane, 1,1,2-trichloroethane and triphenyl phosphate) based on estimated avian exposures using fugacity and multimedia fate models for current conditions of use compared to hazard information including existing in vivo test data for the chemicals and analogs, interspecies correlation estimates and results from hundreds of acute avian dietary toxicity studies. The data indicated that acute avian toxicity is not likely to be observed below 10 ppm in the diet for any chemical with the exception of those with a specific mode of toxic action. Modeling indicated low exposure potential for terrestrial birds to any of the three chemicals, with estimated dietary concentration of less than 0.001 ppm. Despite uncertainty associated with the underlying data sources, the four order of magnitude gap between potential exposure and a minimum hazard threshold suggests that additional avian in vivo testing would not generate valuable data. However, a weight of evidence approach for integrating data is necessary to engender greater confidence among government decision-makers in cases where data from a particular in vivo study is not expected to improve risk decision-making and an existing data gap can remain unfilled.

Capabilities of satellite Geostationary Environment Monitoring Spectrometer (GEMS) NO2 data for hourly ambient NO2 exposure modeling.

The Geostationary Environment Monitoring Spectrometer (GEMS) is the world's first geostationary instrument that monitors hourly gaseous air pollutant levels, including nitrogen dioxide (NO2). Using the first-of-its-kind capabilities of GEMS NO2 data, we examined how well GEMS NO2 levels can explain the spatiotemporal variabilities in hourly NO2 concentrations in the Republic of Korea for the year 2022. A correlation analysis between hourly GEMS NO2 levels and ground NO2 concentrations showed a higher spatial correlation [Pearson r= 0.56 (SD= 0.20)] than a temporal one [Pearson r= 0.42 (SD= 0.14)], on average. To take advantage of the enhanced spatial predictability of GEMS NO2 data, we employed a mixed effects model to allow hour-specific relationships between GEMS NO2 and NO2 concentrations on a given day in each region and subsequently estimated hourly NO2 concentrations in all urban and rural areas. The 10-fold cross validation demonstrated R2= 0.72, mean absolute error (MAE)= 3.7 ppb, and root mean squared error (RMSE)= 5.5 ppb. The hourly variations of the relationships were attributed particularly to those of wind speed among meteorological parameters considered in this study. The spatial distributions of hourly estimated NO2 concentrations were highly correlated between hours [average r= 0.91 (SD= 0.06)]. Nonetheless, they represented the diurnal patterns of urban versus rural NO2 contrasts during the day [urban/rural NO2 ratios from 1.22 (5 pm) to 1.37 (12 pm)]. The newly retrieved GEMS NO2 data enable temporally as well as spatially resolved NO2 exposure assessment. In combination with the time-activity patterns of individual subjects, the GEMS NO2 data can generate 'sub-population' exposure estimates and therefore enhance health effect studies.

Quantitative Microbial Risk Assessment of Antibiotic-Resistant E. coli, Legionella pneumophila, and Mycobacteria in Nonpotable Wastewater Reuse Applications.

Antibiotic-resistant bacteria (ARB) have become a major threat to public health and modern medicine. A simple death kinetics-based dose-response model (SD-DRM) was incorporated into a quantitative microbial risk assessment (QMRA) to assess the risks of exposure to reclaimed wastewater harboring antibiotic-resistant E. coli, Legionella pneumophila, and Mycobacterium avium for multiple exposure scenarios. The fractions of ARB and trace antibiotics present in the body were incorporated to demonstrate their impact on infection risks. Both ARB and antibiotic susceptible bacteria, ASB, are assumed to have the same dose-response in the absence of antibiotics but behave differently in the presence of residual antibiotics in the body. Annual risk of L. pneumophila infection exceeded the EPA 10-4 pppy (per person per year) benchmark at concentrations in reclaimed water greater than 103-104 CFU/L, depending on parameter variation. Enteropathogenic E. coli infection risks meet the EPA annual benchmark at concentrations around 105-106 total E. coli. The results illustrated that an increase in residual antibiotics from 0 to 40% of the minimum inhibitory concentration (MIC) reduced the risk by about 1 order of magnitude for E. coli but was more likely to result in an untreatable infection.

Safe(r)-by-design principles in the thermoplastics industry: guidance on release assessment during manufacture of nano-enabled products.

Background: The application of nanomaterials (NMs) and nano-enabled products (NEPs) across many industries has been extensive and is still expanding decades after first being identified as an emerging technology. Additive manufacturing has been greatly impacted and has seen the benefits of integrating NMs within products. With the expansion of nanotechnology, there has been a need to develop more adaptive and responsive methods to ascertain risks and ensure technology is developed safely. The Safe(r)-by-Design (SbD) concept can be used to establish safe parameters and minimise risks during the materials' lifecycle, including the early stages of the supply chain. Exposure monitoring has advanced in recent years with the creation of standardised protocols for occupational exposure assessment of nano-objects and their aggregates and agglomerates (NOAA). Methods: To aid in the development of an online SbD-supporting platform by the EU-funded project SAbyNA, we adopt a Europe Standard for monitoring release of NOAA to identify if a greater release of NOAA is associated with incorporation of NMs within NEPs compared to a polymer matrix alone. Case studies included filaments of polypropylene (PP) with nano-Ag or polycarbonate (PC) with single-walled carbon nanotubes (SWCNTs). NMs were received in masterbatch, and therefore previously modified to align with SbD interventions. Results were collected in line with European Standard recommendations: monitoring particle concentrations using direct reading instruments (DRI), sampling for offline chemical and morphological analysis, and collecting contextual information. Results and discussion: Based on the criteria described in the European standard (BS EN 17058), data from both case studies identified that inhalation exposure relating to NM was "unlikely". Despite this, during the production of the SWCNT-PC filaments, some noteworthy observations were made, including several DRI activity measurements shown to be higher than background levels, and material morphologically similar to the reference SWCNT/polymeric masterbatch observed in offline analysis. The data collected during this campaign were used to discuss choices available for data interpretation and decision-making in the European Standard for monitoring release of NOAA and also to facilitate the development of SAbyNA's user-friendly industry platform for the SbD of NMs and NEPs.

A Novel Approach to Assessing the Joint Effects of Mercury and Fish Consumption on Neurodevelopment in the New Bedford Cohort.

Understanding health risks from methylmercury (MeHg) exposure is complicated by its link to fish consumption which may confound or modify toxicities. One solution is to include fish intake and a biomarker of MeHg exposure in the same model, but resulting estimates do not reflect the independent impact of accumulated MeHg or fish exposures. In fish-eating populations, this can be addressed by separating MeHg exposure into fish intake and average Hg content of the consumed fish. We assessed the joint association of prenatal MeHg exposure (maternal hair Hg) and fish intake (among fish-eating mothers) with neurodevelopment in 361 eight-year-olds from the New Bedford Cohort (born 1993-1998). Neurodevelopmental assessments used standardized tests of IQ, language, memory, and attention. Covariate-adjusted regression assessed the association of maternal fish consumption, stratified by tertiles of estimated average fish Hg, with neurodevelopment. Associations between maternal fish intake and child outcomes were generally beneficial for those in the lowest average fish Hg tertile, but detrimental in the highest average fish Hg tertile where, for example, each serving of fish was associated with 1.3 fewer correct responses (95% CI: -2.2, -0.4) on the Boston Naming test. Standard analyses showed no outcome associations with hair Hg or fish intake.

A sustainable and innovative method to determine parabens in body creams for exposure and risk assessment.

Methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), and butylparaben (BuP) are among the most widely used preservatives in cosmetics, drugs, and foods. These compounds have been associated with toxic effects due to the overuse of products with parabens in their formulation. The toxicity of parabens may be correlated to endocrine disruption, owing to their ability to mimic the actions of estradiol. In this paper, a simple, sustainable, robust, and innovative dispersive liquid-liquid microextraction (DLLME) technique was developed and employed to extract these xenobiotics from body cream samples, aiming to calculate the margin of safety (MoS) to assess the risk of exposure. The validated method presented suitable linearity (r > 0.99), lower limits of detection (ranging from 0.01 to 0.04 % w/w), and satisfactory precision and accuracy (ranging from 4.33 to 10.47, and from -14.25 to 13.85, respectively). Seven of the ten analysed samples presented paraben contents within the acceptable concentration according to European legislation. The MoS value obtained for PrP (37.58) suggested its reduced safety, indicating that PrP may significantly contribute to systemic exposure resulting from the use of personal care products.

Exploring avian exposure to parent polycyclic aromatic hydrocarbons (PAHs): Using the common eider Somateria mollissima in a global context.

Compared to other organic contaminants, birds are rarely studied for their exposure to polycyclic aromatic hydrocarbons (PAHs), mainly due to their effective metabolization of parent PAHs. However, as some studies suggest, exposure to PAHs may result in adverse health effects including decreased survival, especially following oil spills. In the present study, we analyzed samples from a sea duck, the common eider Somateria mollissima including feathers, preen oil, blood, liver and bile, to evaluate whether non- lethally collected samples could be reliably used for avian biomonitoring strategies. Phenanthrene was the only individual PAH detected across sample types, with the highest concentration found in preen gland and the lowest in blood. Significant differences in concentrations were observed between bile vs preen gland and liver vs preen gland, while for most compounds neither blood nor feathers showed detectable levels of parent PAHs. Therefore, the utility of those sample types for PAH exposure assessment may be limited and should be interpreted with caution, moreover as several physiological factors may affect them. Additionally, we also provide a comparison with the available literature to review current avian PAH exposure assessment and outline future research focused needs.

Occupational exposure to pesticides and neurobehavioral outcomes. Impact of different original and recalled exposure measures on the associations.

BACKGROUND: Several measures of occupational exposure to pesticides have been used to study associations between exposure to pesticides and neurobehavioral outcomes. This study assessed the impact of different exposure measures for glyphosate and mancozeb on the association with neurobehavioral outcomes based on original and recalled self-reported data with 246 smallholder farmers in Uganda. METHODS: The association between the 6 exposure measures and 6 selected neurobehavioral test scores was investigated using linear multivariable regression models. Exposure measures included original exposure measures for the previous year in 2017: (i) application status (yes/no), (ii) number of application days, (iii) average exposure-intensity scores (EIS) of an application and (iv) number of EIS-weighted application days. Two additional measures were collected in 2019: (v) recalled application status and (vi) recalled EIS for the respective periods in 2017. RESULTS: Recalled applicator status and EIS were between 1.2 and 1.4 times more frequent and higher for both pesticides than the original application status and EIS. Adverse associations between the different original measures of exposure to glyphosate and 4 neurobehavioral tests were observed. Glyphosate exposure based on recalled information and all mancozeb exposure measures were not associated with the neurobehavioral outcomes. CONCLUSIONS: The relation between the different original self-reported glyphosate exposure measures and neurobehavioral test scores appeared to be robust. When based on recalled exposure measures, associations observed with the original exposure measures were no longer present. Therefore, future epidemiological studies on self-reported exposure should critically evaluate the potential bias towards the null in observed exposure-response associations.

Key environmental exposure pathways to antimicrobial resistant bacteria in southern Malawi: A SaniPath approach.

Antimicrobial resistance (AMR) poses a severe global health threat, yet the transmission pathways of AMR within communal public environments, where humans and animals interact, remain poorly explored. This study investigated AMR risk pathways, prevalence, and seasonality of extended-spectrum ß-lactamase (ESBL) producing E. coli and K. pneumoniae, and observed practices contributing to environmental contamination within urban, peri-urban, and rural Malawi. Using the SaniPath tool, in August 2020, transect walks across three Malawian study sites identified potential AMR exposure pathways, including drains, standing water, soil, and areas of communal hand contact. Subsequently, from September-2020 to August-2021, 1440 environmental samples were collected at critical points along exposure routes (n = 40/month from each site). These underwent microbiological analysis using chromogenic agar techniques to detect the presence of ESBL E. coli and ESBL K. pneumoniae. Results showed the highest ESBL prevalence in urban environments (68.1 %, 95%CI = 0.64-0.72, p < 0.001) with a higher ESBL presence seen in drains (58.8 %, 95%CI = 055-0.62, p < 0.001) and soil (54.1 %, 95%CI = 0.46-0.62, p < 0.001) compared to other pathways. Environmental contamination was attributed to unavailability and poor condition of sanitation and hygiene infrastructure based on key informant interviews with community leaders (n = 9) and confirmed by independent observation. ESBL prevalence varied between seasons (χ2 (2,N = 1440) = 10.89, p = 0.004), with the highest in the hot-dry period (55.8 % (n = 201)). Prevalence also increased with increased rainfall (for ESBL E.coli). We highlight that community environments are likely to be a crucial component in AMR transmission, evident in the abundance of ESBL bacteria in identified exposure pathways. Additionally, poor sanitation infrastructure and practices coupled with seasonal dynamics further affect the presence of ESBLs in communal environments. Therefore, a context appropriate whole system approach that tackles infrastructure and behavioural factors, supported by effective surveillance is required to impact AMR and a range of aligned development challenges in these settings.

Concentration and health risk assessment of 16 rare earth elements in six types of tea in China.

Rare Earth Elements (REEs) have been implicated in potential health effects. However, the health risk of REE exposure among tea drinkers in China remains poorly understood. This study aimed to characterize the concentration of REEs in different tea categories and evaluate the associated health risks for tea consumers in China. By analyzing the content of 16 REEs in 4326 tea samples from China, the exposure level of REEs to the general population was estimated. The content of these 16 REEs was similar across six types of tea, with oolong tea exhibiting the highest levels. The concentration of light rare earth elements (LREEs) in six types of tea was higher than that of heavy rare earth elements (HREEs). The daily mean and 95th percentile (P95) exposure to REEs from tea for the general population in China were 0.0328 µg/kg BW and 0.1283 µg/kg BW, respectively, which are significantly lower than the temporary acceptable daily dose (tADI). Our findings suggest that REEs from tea do not pose a known health risk to Chinese consumers.

Characterizing applications, exposure risks, and hazard communication for engineered nanomaterials in construction.

BACKGROUND: Engineered nanomaterials (ENMs) may pose health risks to workers. Objectives were to characterize ENM applications in construction, identify exposure scenarios, and evaluate the quality of safety data sheets (SDSs) for nano-enabled construction products. METHODS: SDSs and product data were obtained from a public database of nano-enabled construction products. Descriptive statistics were calculated for affected trades, product categories, and types of ENMs. A sample of SDSs (n = 33) was evaluated using modified criteria developed by NIOSH researchers. Bulk analysis via transmission electron microscopy characterized nanoparticles in a subset of products. RESULTS: Companies report using >50 ENMs in construction products. ENM composition could not be determined via SDSs for 38.1% of the 907 products examined. Polymers and metal oxides tied for most frequently reported ENMs (n = 87, 9.6%). Nano silica, graphene, carbon nanotubes, and silver nanoparticles were also frequently reported. Most of the products were paints and coatings (n = 483, 53.3%), followed by pre-market additives, cementitious materials, insulation, and lubricants. Workers in twenty construction trades are likely to handle nano-enabled products, these particularly encompass cement and brick masons, painters, laborers, carpenters, glaziers, and insulators. A wide range of exposure scenarios were identified. SDSs were classified as satisfactory (18%), in need of improvement (12%), or in need of significant improvement (70%). Bulk analyses revealed discrepancies between actual ENM composition and those in SDSs. DISCUSSION AND CONCLUSION: There has been significant progress investigating risks to construction workers posed by ENMs, but SDSs need major improvements. This study provides new insights on the use of ENMs in construction, exposure risks, and hazard communication.

Assessment of the exposure to cytotoxic Bacillus cereus group genotypes through HTST milk consumption.

This study addresses the limited tools available for assessing food safety risks from cytotoxic Bacillus cereus group strains in contaminated food. We quantified the growth, in skim milk broth, of 17 cytotoxic B. cereus strains across 6 phylogenetic groups with various virulence gene profiles. The strains did not grow in HTST milk at 4 or 6°C. At 10°C, 15 strains exhibited growth; at 8°C, one strain grew; and all strains grew at temperatures ≥ 14°C. Using growth data from 16 strains, we developed linear secondary growth models and an exposure assessment model. This model, simulating a 5-stage HTST milk supply chain and up to 35 d of consumer storage with an initial contamination of 100 cfu/mL, estimated that 2.81 ± 0.66% and 4.13 ± 2.53% of milk containers would surpass 105 cfu/mL of B. cereus by d 21 and 35, respectively. A sensitivity analysis identified the initial physiological state of cells (Q0) as the most influential variable affecting predictions for specific isolates. What-if scenarios indicated that increases in mean and variability of consumer storage temperatures significantly affected the predicted B. cereus concentrations in milk. This model serves as an initial tool for risk-based food safety decision making regarding low-level B. cereus contamination.