Low-level Exposure Research Articles

Longitudinal maternal glycemia during pregnancy and placental epigenetic age acceleration

BackgroundDysregulation of maternal glucose homeostasis has been related to an increased risk of morbidity and mortality in mothers and fetuses, yet the mechanism remains unclear. This study investigated the association between maternal glycemic levels and placental epigenetic age acceleration (PAA) in a multiethnic cohort.MethodsIn a sample of 301 pregnant women (102 Hispanic, 77 White, 72 Black, and 50 Asian/Pacific Islander), the association of glycemic markers cumulative exposure with PAA was tested using linear regression adjusting for fetal sex, maternal age, educational status, and health insurance status. Models were applied in the full cohort and stratified by race/ethnicity. Further, sensitivity analyses were performed after excluding women with GDM or preeclampsia.ResultsAmong Black women, high glucose, HbA1c, and insulin cumulative exposure levels were associated with lower PAA compared to low cumulative exposure levels (β = − 0.75 weeks, 95% CI = − 1.41 to − 0.08); β = − 0.86, 95% CI = − 1.51 to − 0.21; and β = − 0.76, 95% CI = − 1.49 to − 0.03, respectively). Among Asian/Pacific Islander women, medium insulin cumulative exposure level was associated with lower PAA (β = − 0.94 weeks, 95% CI = − 1.74 to − 0.14). No significant association was observed among White and Hispanic women as well as in the full cohort.ConclusionsElevated glucose, HbA1c, and insulin cumulative levels throughout pregnancy were associated with lower PAA in Black and Asian/Pacific Islander women. Placental epigenetic aging may be altered by maternal elevated glycemia and may in part underlie early programming of health outcomes in pregnancy and childhood health outcomes.

Exploring Calcium Channels as Potential Therapeutic Targets in Blast Traumatic Brain Injury

Background/Objectives: Repeat low-level blast exposure has emerged as a significant concern for military populations exposed to explosive events. Blast-Related Traumatic Brain Injury (bTBI) is a unique form of brain trauma with poorly understood molecular mechanisms. Loss of calcium homeostasis has emerged as a mediator of early neuronal dysfunction after blast injury. This review aims to examine the role of calcium signaling in bTBI, focusing on the dual function of calcium channels as mediators and modulators of injury, and to explore therapeutic strategies targeting calcium homeostasis. Methods: We conducted a review of peer-reviewed articles published between 2000 and 2024, using the databases PubMed, Scopus, and EBSCO. Search terms included “blast traumatic brain injury”, “calcium channels”, and “calcium”. Studies investigating intracellular calcium dynamics after bTBI were included. Exclusion criteria included studies lacking evaluation of calcium signaling, biomarker studies, and studies on extracellular calcium. Results: We identified 13 relevant studies, primarily using preclinical models. Dysregulated calcium signaling was consistently linked to cellular dysfunction, including plasma membrane abnormalities, cytoskeletal destabilization, mitochondrial dysfunction, and proteolytic enzyme activation. Studies highlighted spatially compartmentalized vulnerabilities across neurons and astrocytes, suggesting that targeting specific cellular regions, such as the neuronal soma or axons, could enhance the therapeutic outcome. Therapeutic strategies included pharmacological inhibitors, plasma membrane stabilizers, and modulators of secondary injury. Conclusions: Calcium signaling is implicated in the pathophysiology of bTBI. Standardized experimental approaches would reduce variability in findings and improve the understanding of the relationship between calcium channel dynamics and bTBI and help guide the development of neuroprotective interventions that mitigate injury and promote recovery.

Comparison of Operational Jet Fuel and Noise Exposure for Flight Line Personnel at Japanese and United States Air Bases in Japan

Flight line personnel are constantly exposed to noise and jet fuel while working on flight lines. Studies suggest that jet fuel in combination with noise affects hearing loss more than noise exposure alone. This study examined the combined effects of jet fuel and noise exposure on the hearing of flight line personnel stationed at Japan Air Self-Defense Force Air Bases (Hamamatsu, Matsushima, Hyakuri, Yokota, and Iruma) and US Air Force Air Bases (Kadena and Misawa) in Japan. Samples were collected from all participants, 97 flightline-exposed and 71 control volunteers, to measure their individual noise levels with a personal sound level meter and volatile organic chemicals (VOCs) with a chemical sampling pump during a single shift. Blood samples were collected post shift. Urine samples (entire void) were collected prior to the shift (morning first void) and post shift. VOCs were measured in air, blood, and urine. An audiometric test battery, consisting of immittance measurements, audiograms, distortion product otoacoustic emissions, and the auditory brain response, was conducted after the shift to examine the hearing of participants. Total VOCs in personal air samples were in the ppb range for each group. Tinnitus and temporary hearing loss were reported in audiological histories but were also present in some controls. Noise levels on the flight line were greater than the action level for requiring hearing protection and exceeded exposure limits, but all exposed subjects reported wearing hearing protection. Audiometric tests identified significant differences and trends between flight line and control personnel, indicating the potential for hearing disorders. In spite of very low levels of VOC exposure and wearing hearing protection for noise, there is still the potential for hearing issues in flight line personnel.

A mediation analysis of meteorological factors on the association between ambient carbon monoxide and tuberculosis outpatients visits

BackgroundAmbient carbon monoxide (CO) exposure has been identified as an emerging environmental risk factor contributing to the progression of pulmonary tuberculosis (PTB). However, the epidemiological evidence remains inconsistent. This study aims to investigate the short-term association between low-level CO exposure and PTB outpatient visits in a developing region.MethodsWe conducted a time-series study utilizing a distributed lag non-linear model (DLNM) combined with mediating effect analysis, based on daily CO and PTB cases from 2011 to 2020 in Ningbo, China.ResultsAmong all patients with PTB, a 0.1 mg/m3 increase in CO concentration was associated with an increased risk of PTB outpatient visits in the single-pollutant model, particularly at lag days 2–6. The maximum relative risk (RR) was 1.091 (95%CI, 1.020–1.168, lag 0–2 days). Similarly, the maximum cumulative lag effect of CO exposure was 1.781 (RR = 1.781, 95%CI: 1.157–2.742, lag 0–15 days). Subgroup analysis revealed a significant effect of CO exposure in males (RR = 1.090, 95%CI: 1.009–1.777, lag 0–3 days), females (RR = 1.101, 95%CI: 1.014–1.195, lag 0–3 days), younger individuals (RR = 1.097, 95%CI: 1.022–1.178, lag 0–2 days), and during the warm season (RR = 1.012, 95%CI: 1.002–1.022, lag 0–4 days). Mediation analysis indicated that temperature had an indirect mediating effect on association between CO and PTB (−0.0065, 95%CI: −0.0130 to −0.0004), while air pressure, visibility, and humidity showed no significant mediating effects.ConclusionOur findings indicate that ambient CO exposure, even at low levels, has a short-term impact on PTB in developing regions. Temperature plays a partial mediating role in this relationship. Consequently, it is critical to enhance environmental monitoring and early warning systems to effectively address the prevalence of PTB and the delays in health-seeking behavior.

What about the workers? An update

Epidemiological studies of nuclear industry workers are of substantial importance to understanding the risk of cancer consequent to low-level exposure to radiation, and these studies should provide vital evidence for the construction of the international system of radiological protection. Recent studies involve large numbers of workers and include health outcomes for workers who accumulated moderate (and even high) doses over prolonged periods while employed during the earlier years of the nuclear industry. The interpretation of the findings of these recent studies has proved to be disappointingly difficult. There are puzzling patterns of results involving the period of first employment and monitoring for radionuclide intakes, depending on the particular study examined. Explaining these patterns is crucial for a reliable understanding of results in terms of occupational radiation exposure. In this paper, an updated review of nuclear worker studies is presented in the context of these patterns of results, making use of the latest relevant results. It is apparent that the strikingly raised risks for mortality from solid cancers for workers hired in later years reported from the International Nuclear Workers Study (INWORKS) is effectively confined to workers at five nuclear facilities in the USA, and that the notable variation of risks in INWORKS between workers monitored or not for radionuclide intakes is driven by UK workers. These are the areas where effort must be concentrated before a confident derivation of radiation risk estimates can be obtained from these nuclear worker studies.

Uranium Exposure and Kidney Tubule Biomarkers in the Multi-Ethnic Study of Atherosclerosis (MESA).

Experimental studies indicate that uranium exposure is toxic to the kidney tubules. We evaluated the association of urinary uranium concentrations with biomarkers of tubule cell dysfunction (alpha-1-microglobulin [A1M], uromodulin [UMOD], epidermal growth factor [EGF]), and tubule cell injury (kidney injury molecule-1 [KIM-1], monocyte chemoattractant protein-1 [MCP-1], and chitinase-3-like protein 1 [YKL-40]), as well as with albuminuria and estimated glomerular filtration rate (eGFR) among participants in the Multi-Ethnic Study of Atherosclerosis (MESA). We conducted a cross-sectional study that included 461 participants selected for the absence of diabetes, chronic kidney disease (CKD), and cardiovascular disease, evaluated with six kidney tubule biomarker measurements. Urinary uranium concentrations were measured using inductively coupled plasma mass spectrometry in spot urine samples. Linear models were used to determine associations of urinary uranium concentrations with each kidney tubule biomarker, calculated by the geometric mean ratio (GMR), after adjustment for participant's urinary creatinine concentrations, age, sex, race/ethnicity, MESA site location, highest level of education completed, cigarette smoking status, alcohol consumption, body mass index (BMI), albuminuria levels, and eGFR. Median (interquartile range) urinary uranium concentration was 5.2 (2.9, 10.4) ng/L, and mean (standard deviation) eGFR was 99 (16) mL/min/1.73 m2. The adjusted GMRs (95%CI) of KIM-1 and MCP-1 were 1.11 (1.01, 1.22) and 1.10 (1.01, 1.20), respectively per 7.5 ng/L (interquartile range) higher urinary uranium concentration, while no statistically significant associations were observed for YKL-40, A1M, UMOD, EGF, albuminuria, or eGFR. In flexible dose-response models, the associations were positive and largely linear between urinary uranium concentrations and higher KIM-1 and MCP-1. Among healthy community-living individuals, chronic low-level uranium exposure, as measured in urine, was associated with markers of kidney tubule cell injury. Chronic low-level uranium exposure observed in contemporary US urban centers may adversely affect kidney tubule health and related outcomes.

Bisphenol A and its potential mechanism of action for reproductive toxicity.

Bisphenol A (BPA) is an organic synthetic chemical used worldwide. Billions of pounds of BPA are produced annually through industrial processes to be used in commercial products, making human exposure to BPA ubiquitous. Concerns have been raised due to the potential adverse health effects of BPA, specifically in vulnerable populations, such as pregnant persons and children. BPA is an endocrine-disrupting chemical, and through this function has been linked to reproductive toxicity. We review BPA's historical and current use, health and safety concerns and regulations, sources of exposure, and evidence for male and female reproductive toxicity. Evidence from epidemiological and animal studies idenfity that low- and high-exposure levels of BPA (prenatal, postnatal and adulthood exposure) can adversely affect male and female fertility and reproductive organs. While the cause of BPA-induced reproductive toxicity is not fully understood, we discuss BPA's estrogenic and androgenic activity, and its ability to disrupt the hypothalamic-pituitary-gonadal axis as a potential associated mechanism. There are significant differences in tolerable daily intakes of BPA set by global agencies, making interpretation of previous and emerging research findings challenging and inconsistent. Although BPA is deemed toxic by some government agencies, most do not currently consider it a health risk due to low populational exposure levels. However, we highlight evidence that even at acute, low exposure, BPA can adversely affect reproductive function. We recommend continuing research into the adverse effects of BPA on human health and revisiting the regulatory measures of BPA to limit exposure and promote public awareness of its potential to cause reproductive toxicity.

Volatile methylsiloxane levels of settled dust in hair salons: Spatial and occupational exposure trends.

Volatile methylsiloxanes (VMS) are prevalent ingredients of personal care products, including hair care products. Hair salons, in which these products are frequently used, exposes residents to significant VMS levels. Therefore, this study investigated seven different VMS compounds in the dust from 50 hair salons. The median total VMS concentration was 906 (6.19-64,200) μg·g-1, primarily comprising dodecamethylcyclohexasiloxane (D6, 452μgg-1), followed by octamethylcyclotetrasiloxane (D4, 303μgg-1). Potential sources of cyclic VMS compounds are PCPs, while for linear VMS, they are laundry detergents, mainly used for towels in hair salons. Statistically significant spatial differences were observed between hair salons in different districts in the city, possibly influenced by socioeconomic factors, with hexamethylcyclotrisiloxane (D3), D4, and D6 showing the greatest variation among all the VMS compounds based on district. Winter and summer samples exhibited seasonal differences within the same district, with winter samples showing higher VMS concentrations owing to decreased ventilation. Ingestion exposure assessments revealed greater VMS exposure for hair salon workers in higher socioeconomic areas under normal case exposure conditions (normal ingestion rate with 8h of exposure, up to 2.62ng·day-1kg-1), whereas worst-case exposure (higher ingestion rate with 12h of exposure) was approximately 3.79 times higher. Hair salons were the most exposed to D6 in all the districts through dust ingestion. A comparison with other studies revealed lower exposure levels in the present study.

Advancements in Heavy Metal Detection Using Microneedle Array Technology

Heavy metal and metalloid (HM) exposure poses significant health risks, including cardiovascular disease, cancer, and renal damage. This contamination, prevalent in the Western U.S., involves Arsenic (As), Cadmium (Cd), Uranium (U), and Vanadium (V). Interstitial fluid (ISF) is a source of biomarkers, which can be minimally invasively collected using microneedle array (MA) technology. Our study hypothesized that MA-extracted ISF would facilitate non-invasive HM quantification. We established analytical parameters for HM detection in ISF using inductively coupled plasma-mass spectrometry (ICP-MS), defined baseline ISF HM concentrations in unexposed animal populations, and monitored HM levels in ISF under mixed exposure in animal models. Additionally, we assessed HM levels in ISF and biological fluids from three human subjects. Thirty-six Sprague Dawley rats were divided into cohorts: low-level mixed HMs exposure (5X maximum contaminant level (MCL)); high-level single HM with low-level others (50X MCL for one HM with 5X for others); and unexposed controls. ISF and plasma were collected weekly for eight weeks and analyzed via ICP-MS. Our findings reveal a correlation between ISF and plasma HM levels, underscoring ISF’s potential for real-time monitoring of HM exposure. This study also establishes baseline ISF HM levels, illustrating the feasibility of HM quantification using small ISF volumes.

Inequitable Air Quality Improvement in China: Regional and Population-Level Disparities in PM Exposure (2013–2020)

Over the past decade, China has enacted forward-looking environmental policies that have significantly reduced air pollution. However, while there appears to be a synergy between economic development and improvements in air quality, regional imbalances in development and disparities in health risks underscore systemic challenges in environmental governance. This study employed a population-weighted exposure index to evaluate disparities in PM2.5 exposure and its temporal and spatial trends, considering multidimensional socio-economic factors such as education, age, gender, occupation, and urban/rural backgrounds across 32 provinces and regions in China. The findings reveal that despite a notable decline in overall PM2.5 concentrations between 2013 and 2020, improvements in air quality are uneven across regions, with less developed areas bearing a disproportionate burden of emission reductions. Urban centers exhibit lower exposure levels due to resource and industrial advantages, whereas towns experience higher risks of air pollution. Socio-economic disparities are evident, with increased exposure observed in high-pollution industries and among groups with lower educational attainment. Women are more likely to be exposed than men, and both the elderly and children face higher risks. To address these challenges, policies should focus on the economic development of underdeveloped regions, balance environmental protection with growth, prioritize heavily polluted areas and vulnerable populations, and promote the adoption of clean energy to mitigate pollution inequality.

The Impact of Mercury from Dental Amalgams on Pregnancy and Childhood: A Health and Risk Assessment Evaluation.

Mercury is a pervasive global pollutant, with primary anthropogenic sources including mining, industrial processes, and mercury-containing products such as dental amalgams. These sources release mercury into the environment, where it accumulates in ecosystems and enters the food chain, notably through bioamplification in marine life, posing a risk to human health. Dental amalgams, widely used for over a century, serve as a significant endogenous source of inorganic mercury. Studies have demonstrated that mercury vapor can be released from amalgams at room temperature due to material corrosion, potentially leading to chronic exposure. Pregnant women and children are particularly susceptible to mercury's toxic effects, with research linking prenatal mercury exposure to developmental delays, neurocognitive deficits, and conditions such as autism spectrum disorder. Moreover, the long-term accumulation of mercury in the body raises concerns about delayed health impacts in individuals exposed during childhood. Recent findings suggest even low levels of mercury exposure may contribute to kidney damage mediated by oxidative stress, highlighting the importance of monitoring mercury levels in vulnerable populations. Prenatal mercury transfer and postnatal exposure through breastfeeding further amplify the risks. This review critically assesses the health implications of mercury exposure from dental amalgams, focusing on its impact on pregnancy and childhood development. It underscores the need for updated regulatory measures to mitigate mercury-related risks and calls for further research to clarify the extent of mercury's long-term effects on human health.

BMI-mediated association between glyphosate exposure and increased risk of atherosclerotic heart disease: A large-scale cross-sectional study.

Glyphosate, as the main component of glyphosate pesticides, has been shown to have toxic effects on multiple human systems. However, the association between glyphosate and atherosclerotic cardiovascular disease (ASCVD) remains unclear. This study aims to explore the effect of glyphosate exposure on ASCVD. This study involved 1,602 participants and employed various statistical techniques, such as multivariable logistic regression, linear fitting, mediation analysis, subgroup analysis, and sensitivity analysis, to elucidate the association between glyphosate exposure and cardiovascular diseases. Compared with the low level of glyphosate exposure, the risk of ASCVD increased significantly with high level of glyphosate exposure (OR = 2.05, 95%CI = 1.17-3.58, p<0.05, p for trend<0.05), which showed a linear upward trend. Further analysis found that exposure to high levels of glyphosate and angina pectoris (OR = 2.84, 95%CI = 1.00-8.04, p<0.05, p for trend<0.05), coronary heart disease (OR = 3.76, 95%CI = 1.80-7.83, p<0.01, p for trend<0.05), heart attack (OR = 2.65, 95%CI = 1.35-5.23, p<0.01, p for trend = 0.09) were associated. Mediating analysis found that BMI mediated the association between glyphosate exposure and ASCVD, with an indirect effect of 0.002405(95%CI: 0.000182-0.01, p = 0.02) and a direct effect of 0.039336(95%CI: 0.000391-0.09), total effect of 0.041741(95%CI: 0.002112-0.10). Increased exposure to glyphosate is associated with an increased risk of ASCVD, and BMI plays a mediating role in this association. In addition, glyphosate exposure is associated with a higher risk of angina, coronary heart disease, and heart attack.

Exploring the potential of MRM-IDA-EPI method in mass spectrometry for exposomic analysis: a commentary.

Exposomics is a field that studies environmental exposures and their impact on human health. The MRM-IDA-EPI method, which combines targeted and untargeted mass spectrometry methods, is useful for identifying and quantifying biomarkers in various biological matrices. The method's accuracy and precision in forensic toxicological screening suggest potential applications for detecting low-level environmental exposures. It can help detect and understand environmental exposures, explain their metabolic processes, and assess their impact on human health more effectively.

Pulmonary function in swimmers exposed to disinfection by-products: a narrative review.

Swimming produces many psychophysiological effects, including blood, hormonal, enzymatic, pulmonary, cardiovascular and energetic adaptations. However, asthma and allergies are becoming increasingly prevalent medical issues among elite endurance-trained swimmers, where exercise-induced asthma or bronchospasm is frequently reported. Heavy endurance swimming training, especially under adverse conditions, stresses the airway mucosa, leading to inflammatory changes, as observed in induced sputum in competitive swimmers. In addition, chlorine-based disinfectants (CBDs) are commonly used in indoor pools due to their effectiveness and lower relative cost. Many of these substances have carcinogenic and genotoxic properties, and exposure to DBPs have been linked to adverse respiratory effects. The association between long-term exposure to a chlorinated swimming pool and elevated serum sIgE levels suggests a link between allergens, chlorine exposure and the development of various pulmonary dysfunctions. Thus, the combination of intense and repeated physical endurance training over extended periods, along with suboptimal environmental conditions, may contribute to the development of rhinitis, asthma and bronchial hyperresponsiveness in athletes. While occasional or low-level exposure to chlorine might not be harmful, regular swimmers, especially those at competitive levels, are at a higher risk of developing respiratory disorders. Because these potential risks of exposure to CBDs must be balanced against the benefits of swimming and the risk of microbial infections in pools, we recommend better pool management and regular health checks for swimmers. Fortunately, the reduction of bronchial symptoms in swimmers who reduce training volume and intensity suggests that the negative effects on pulmonary function may be reversible. For these reasons, it is crucial to develop effective respiratory protection strategies, including medical interventions and modifications to the pool environment. Practical steps such as reducing chlorine use, ensuring proper hygiene before swimming and using swim caps can minimise risks. Research should also explore safer alternatives to CBDs, such as ozonation, and improved ventilation to reduce air pollutants.

Prenatal Exposure to PFAS and the Association With Neurobehavioral and Social Development During Childhood

Exposure to per- and polyfluoroalkyl substances (PFAS) is ubiquitous and may be associated with neurodevelopmental toxicity. However, epidemiological studies report mixed results on the risks of gestational PFAS exposure for children's neurobehavioral impairment. We aimed to examine the associations between prenatal PFAS exposure and children's neurobehavioral and social problems. We measured plasma concentrations of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorohexane sulphonate (PFHxS) in first-trimester blood from 757 women from the Canadian Maternal-Infant Research on Environmental Chemicals (MIREC) study. Children were assessed at 3-4 years with the Behavior Assessment System for Children-2 (BASC-2) and the Social Responsiveness Scale-2 (SRS-2) (n=756 and 496, respectively). We used multivariable linear regression to examine associations between individual and summed log2-transformed PFAS and scores on these assessments. Effect modification by sex was evaluated through interaction terms and stratified analyses. In the sample combining both sexes, a doubling of maternal PFOA was significantly associated with lower T-scores on the following SRS-2 scales: Social Motivation, DSM-Social Communication, and SRS Total score (B ranging from -1.08 to -0.78), suggesting lesser impairments with higher exposure. In sex-stratified analysis, PFOA was related to significantly lower T-scores in boys for these BASC-2 scales: Behavioral Symptoms Index, Externalizing Problems, Aggression, and Hyperactivity (B ranging from -1.32 to -1.03). In girls, however, PFAS were associated with more problem behaviors, but most associations were small and the CIs included the null, with the exception of PFOA being significantly associated with higher T-scores for the BASC-2Anxiety scale (B=1.84, 95% CI: 0.36, 3.32). In conclusion, we did not observe strong associations between prenatal exposure to the PFAS evaluated and children's neurobehavioral and social development in this population with low exposure levels. The results show mixed findings, depending on children's sex, neurodevelopmental outcome, and specific PFAS.

Association between exposure to pyrethroids and chlorpyrifos at age 5 years and IQ at age 7 years among children from the Odense Child Cohort, a prospective birth cohort study.

Over the past decade, the use of organophosphate insecticides including chlorpyrifos has faced increasing restrictions due to health concerns, leading to a rise in use of pyrethroids. Concerns about neurodevelopmental insults following pyrethroids exposure exist, but few studies have examined the long-term effects of childhood exposure to chlorpyrifos and pyrethroids on IQ. To investigate the prospective associations between pyrethroids and chlorpyrifos exposure at age 5 years and IQ scores assessed at age 7. A total of 1083 children from the Odense Child Cohort (OCC), born between 2010 and 2012, were included. Chlorpyrifos metabolite chlorpyrifos-methyl, 3,5,6-trichloro-2-pyridinol (TCPy) and pyrethroid metabolite 3-phenoxy-benzoic acid (3-PBA) were measured in urine at age 5. An abbreviated version of the Danish Wechsler Intelligence Scale for Children fifth edition (WISC-V) was administered at age 7 years. Median urine concentrations of 3-PBA and TCPy at age 5 were 0.18μg/L and 1.15μg/L, respectively. Higher childhood urine TCPy concentration was associated with a reduction in IQ at 7 years (-0.80 (95%CI: -1.29, -0.31)) for each doubling of TCPy. The association was more pronounced in girls (-1.09 (95%CI: -1.80, -0.38)) than in boys. (-0.54 (95%CI: -1.21, -0.14)). No association was observed for 3-PBA. Even in this low exposed cohort, early childhood exposure to chlorpyrifos was associated with lower IQ at age 7. Our results align with previous reports in both animals and humans suggesting that chlorpyrifos exposure may adversely affect neurodevelopment. No association between pyrethroid exposure (3-PBA) and IQ scores was found. The lack of association for 3-PBA is likely due to the low and uniform exposure levels among the participants. To establish a definitive exposure-response relationship, studies or combined datasets with greater variability in exposure levels are required. Continued monitoring and regulation of insecticide use are recommended to protect the health of children.

Associations of a metal mixture and vitamin D with sleep duration among adolescents and young adults from the 2011-2018 NHANES cycles.

Heavy metal exposure has been associated with poor sleep, but little is known about the cumulative associations of multiple metals with sleep duration, particularly among adolescents. This study examined the association of blood lead (Pb), cadmium (Cd), and mercury (Hg) concentrations with sleep duration and possible effect modification by vitamin D. The study sample consisted of 16-25-year-olds (n = 2637) from the 2011-2018 National Health and Nutrition Examination Survey. The association of each blood metal and serum vitamin D level with self-reported sleep duration was examined through linear regression models. Interaction terms and stratified models tested the effect modification of metal association with sleep by vitamin D level or status. Cumulative and interactive associations among the metals and serum vitamin D were also estimated using Bayesian Kernel Machine Regression (BKMR). In linear regressions, there was little evidence of an association between individual metals, vitamin D level, and sleep duration. Both linear regressions and BMKR models showed little indication of interactions among metals and vitamin D levels. BKMR results suggested an overall joint association, with longer sleep duration at higher percentile of the metal-vitamin D mixture (75th percentile vs 50th: β=0.07 hours; 95 % CrI: 0.01, 0.13). In the context of low-level metal exposure, individual metals were unrelated to sleep duration. We found some evidence that higher levels of the mixture of blood Pb, Cd, Hg, and serum vitamin D level may be associated with slightly longer sleep duration, underscoring the importance of considering multiple environmental exposures. Additional analyses, especially in higher risk groups (e.g., higher exposures; higher prevalence or severity of vitamin D deficiency) are warranted.

ADVERSE CHILDHOOD EXPERIENCES AND SOCIAL PARTICIPATION ON FRAILTY STATE TRANSITIONS: A 10-YEAR PROSPECTIVE COHORT

Abstract Background Adverse childhood experiences (ACEs) is associated with frailty, while the association with frailty state transitions and the role of social participation remain unclear. This study aimed to investigate the association between ACEs and frailty state transition, alongside the moderation effect of social participation methods Data from 9,621 adults aged 45+ from the CHARLS (2011-2020) were analyzed. Frailty was measured with the frailty index, while ACEs and social participation were measured with a validated questionnaire. The association between ACEs and frailty state transitions was estimated with multi-state models. Interaction analysis was used to examine the moderation effects of social participation. Results Participants exposed to higher ACEs levels (≥ 4) were associated with an increased risk of forward transition (robust to pre-frail, HR=1.36, 95%CI: 1.21-1.53; prefrail to frail, HR=1.38, 95%CI: 1.17 - 1.62) and decreased risk of backward transition (pre-frail to robust, HR = 0.64, 95%CI: 0.54 – 0.76). Additionally, participants with social participation were associated with increased risk of backward transition (frail to pre-frail, HR = 1.14, 95%CI: 1.02 – 1.27). Social participation moderated the association between ACEs exposure and frailty (P for interaction &amp;lt; 0.05), while participants with lower ACEs exposure levels and social participation were associated with an increased risk of transition from frail to pre-frail (ACEs levels =1, HR = 1.57, 95%CI: 1.06 – 2.32; ACEs levels =2, HR = 1.49, 95%CI: 1.02 – 2.17). Conclusion High levels of ACEs exposure were associated with a greater likelihood of adverse frailty development. Older adults with ACEs exposure might benefit from intervention strategies to improve social participation.

Environmental nanoparticles and respiratory health in vertebrates: Analyzing emerging health risks

Environmental nanoparticles have become an area of considerable concern owing to their potential health hazards, particularly for vertebrates subjected to contaminated environments. This review explores the ramifications of these particles on respiratory health, concentrating on their origins, pathways of exposure, and the mechanisms through which they elicit detrimental effects. The primary origins of environmental nanoparticles encompass industrial operations, vehicular emissions, agricultural activities, and the degradation of plastic waste, resulting in the proliferation of nano-sized plastics and other particulates within urban locales. The review delineates inhalation exposure pathways, underscoring the deposition of nanoparticles within the respiratory tract and the challenges posed to respiratory protection. The health ramifications of nanoparticle exposure are scrutinized, accentuating lung inflammation, oxidative stress, and immune responses provoked by inhaled particulates. Furthermore, the review deliberates on the long-term health risks linked to chronic exposure, including the potential onset of chronic respiratory diseases and structural damage to lung tissue. Additionally, the article addresses the limitations of extant research, highlighting the dearth of data pertaining to chronic, low-level nanoparticle exposure in natural environments. It concludes by proposing future directions for research and policy recommendations, including advanced toxicological investigations and regulatory frameworks designed to mitigate nanoparticle pollution. By synthesizing contemporary understanding and identifying critical gaps, this review aspires to elevate awareness regarding the pressing necessity for targeted interventions to safeguard vertebrate respiratory health against the escalating threat posed by environmental nanoparticles.

Household pesticide use: attitudes, behaviors, and health risks

The main objective of the scientific study was to determine the level of use and attitudes toward the use of pesticides designed for domestic use. Pesticides, intentionally released toxic substances, have the potential to cause adverse health effects even at very low exposure levels, including hormonal disorders, asthma, allergies, and cancer. The rate of pesticide usage and attitudes toward pesticides in the home were measured through an online questionnaire that was completed by a total of 250 respondents. Based on the data collected, we found that the majority of respondents use pesticides in their homes to control insects. The questions in the questionnaire were focused on the respondents' practices in handling, application, storage, disposal, and purchasing of pesticides. Exposure to pesticides can result in mild symptoms, such as vomiting, through to more severe consequences like cancer. Despite the risks associated with pesticide use, regulatory measures are in place; however, misuse often stems from improper storage and disposal practices. We found that gender did not influence safe pesticide handling behavior, although women exhibited more responsible behaviour in purchasing, storing, and disposing of pesticides. Compared to men, women had a higher overall mean score for attitude towards pesticides and thus approached pesticides more responsibly than men. We examined differences in pesticide handling behaviour between urban and rural residents. Based on the data collected, we found that attitudes towards pesticides of urban and rural dwellers are not different. Through the statistical analysis, we concluded that respondents' attitudes towards pesticides influence safe behaviour in purchasing, handling, storage, and disposal of pesticides. The more positive the respondents' attitude toward pesticides, the more responsible their attitude towards pesticides.