Background Childhood asthma has been associated with exposure to particulate matter (PM), and the magnitude of this association may differ by particle size. However, many previous epidemiological studies have generally used trimester-specific or annual average PM concentrations as exposure metrics, which may mask the effects of short-term high-concentration exposures. Furthermore, evidence remains limited regarding weekly sensitive windows of PM exposure during pregnancy and infancy, particularly with respect to sex-specific susceptibility. Objective To identify sensitive windows for the associations of PM exposure of different particle size during pregnancy and infancy with childhood asthma and to examine potential sex differences. Methods As part of the China, Children, Homes, Health (CCHH) study, a questionnaire-based survey was conducted from June 2019 to June 2020 to obtain data on asthma-related information from 28788 preschoolers from seven Chinese cities. A spatiotemporal extremely randomized trees (STET) model was employed to estimate exposure to submicron particulate matter (PM₁), fine particulate matter (PM_2.5), and inhalable particulate matter (PM₁₀). Weekly sensitive exposure windows were assessed using distributed lag nonlinear models (DLNMs), followed by sex-stratified analyses. Restricted cubic spline (RCS) functions were further applied among boys and girls to evaluate the dose–response relationship between size-fractionated PM exposure during the week with the largest effect estimate and childhood asthma. Results The mean concentrations of PM₁, PM_2.5, and PM₁₀ across the seven cities were (34.5±7.2), (62.3±10.4), and (103.5±21.9) μg·m⁻³, respectively, with significant between-city differences. Wuhan had the highest PM₁ and PM_2.5 concentrations, Urumqi had the highest PM₁₀ concentration, and Shanghai generally exhibited lower concentrations across all particle size fractions. The sensitive windows for the associations of PM₁, PM_2.5, and PM₁₀ exposure with childhood asthma started at postnatal weeks 15, 17, and 29, respectively, and persisted until week 52. The maximum effect estimates for all three particle sizes were observed at week 52 (PM₁, OR=1.0358, 95%CI: 1.0135, 1.0587; PM_2.5, OR=1.0191, 95%CI: 1.0087, 1.0296; and PM₁₀, OR=1.0103, 95%CI: 1.0047, 1.0159). No sensitive window was identified during the prenatal period. In sex-stratified analyses, exposure to PM₁, PM_2.5, and PM₁₀ during postnatal weeks 18–52, 22–52, and 24–52, respectively, was associated with increased odds of childhood asthma in boys, whereas no sensitive window was identified in girls. Exposure-response curves showed monotonically increasing asthma risks in boys when PM₁, PM_2.5, and PM₁₀ concentrations exceeded 11.9, 22.3, and 41.7 μg·m⁻³, respectively; this pattern was not observed in girls. Conclusion Postnatal exposure to PM rather than prenatal exposure is associated with increased odds of childhood asthma, with distinct sensitive windows during infancy. Smaller particles, particularly PM₁, show larger effect estimates, earlier onset, and longer duration of sensitive windows. Boys appear to be more susceptible to early-life PM exposure than girls, as reflected by strong associations and more distinct sensitive windows.

Objective To identify potential ergonomic risk factors of works and quickly assess their risks of developing work-related musculoskeletal disorders (WMSDs) in the medical staff. Methods A total of 188 medical staff were selected as the research objects using a two-stage random sampling method. The method for the identification of musculoskeletal stress factors (PLIBEL) was used to analyze the adverse ergonomic factors in the work process, and the rapid entire body assessment (REBA) was used to quickly assess the whole-body posture load. Results The PLIBEL assessment results showed that various adverse ergonomic factors affected different parts of the body during the work process of medical staff. Specifically, 18 adverse ergonomic factors were identified in the neck, shoulders, and upper back, while 10 adverse ergonomic factors were identified in the elbow, forearm, hand, and lower back. Rehabilitation therapists and nurses engaged in patient handling in general wards and medication preparation and blood collection were exposed to ≥35 adverse ergonomic factors. The REBA assessment showed that the REBA score was 3-12 points for medical staff during their work process. Rehabilitation therapists were classified as having an extremely high ergonomic risk. High-risk occupations included ward housekeeping nurses, surgery assistant nurses, operating-room instrument nurses, and surgeons. Medium-risk occupations included general ward nurses (medication preparation and blood collection, venipuncture/infusion, and patient handling), intensive care unit (ICU) nurses, internal medicine residents, and dentists. Low-risk occupations included administrative front-desk nurses, outpatient internal medicine physicians, and technicians/physicians in ultrasonography, laboratory medicine, physical examination, and occupational health departments. Conclusion Adverse ergonomic factors of medical staff predominantly affect the neck, shoulders, upper back, elbows, forearms, hands, and the lower back during the work process. Rehabilitation therapists, ward housekeeping nurses, ICU nurses, operating-room instrument nurses, and surgeons are high-risk groups for WMSDs. Attention should be paid to the management and control of adverse ergonomic factors for medical staff to prevent the occurrence of WMSDs.

Objective The study aimed to investigate whether montelukast sodium could alleviate airway inflammatory responses in asthmatic mice by affecting the PHD2/HIF-1α pathway.Methods An allergic asthma model was established by ovalbumin(OVA)induction,and 18 female BALB/c mice were randomly divided into a control group(Con group),an asthma group(OVA group),and an asthma group with montelukast sodium intervention(30 mg/kg montelukast sodium by oral administration 1 h before OVA challenge,Mon group).HE staining was used to analyze the pathological changes in the lungs of mice.Blood cell analyzer and kits were used to determine the number of inflammatory cells and the levels of cytokines,the content of lactic acid and pyruvic acid in the lungs,respectively.RT-PCR and Western blot were used to detect the mRNA and protein expression of HIF-1α,PHD2,E-cad and p120 in the lungs of mice.Results Compared with the Con group,there was a significant increase in the number of eosinophils,lymphocytes,neutrophils and monocytes,the levels of IL-5,IL-13,complement factor D(CFD)and contents of lactate and pyruvate in the lungs of mice in the OVA group.Lung HIF-1α,PHD2,p120 and E-cad mRNA levels were reduced,meanwhile HIF-1α and PHD2 protein expression were upregulated but E-cad and p120 protein expression were downregulated(all with P<0.05).After montelukast sodium intervention,the number of eosinophils and monocytes and CFD expression were significantly decreased in the lungs of Mon group,the contents of lactate and pyruvate were basically restored to normal,and the mRNA and protein expression of HIF-1α,PHD2,p120 and E-cad were effectively improved.Conclusion Montelukast sodium could alleviate the airway inflammatory responses in the lungs of asthmatic mice by regulating the PHD2/HIF-1α signaling pathway.

Background The association between occupational physical activity (OPA) and cardiometabolic risk factors remains controversial, potentially due to differences in the associations between OPA and various cardiometabolic indicators, as well as the lack of a clearly defined optimal OPA range for multiple-indicator synergistic benefits. Objective To investigate the relationship between OPA and cardiometabolic risk factors in individuals at high risk of cardiovascular disease (CVD) in Hubei Province, and to explore an optimal OPA range for multi-indicator improvements. Methods Data were derived from the Hubei Province dataset of the China Health Evaluation And Risk Reduction Through Nationwide Teamwork from 2015 to 2023, including 19028 high-risk CVD individuals. OPA (metabolic equivalent·h·d⁻¹, MET·h·d⁻¹) was assessed using the China Kadoorie Biobank physical activity questionnaire, anthropometric measurements (height, weight, waist circumference) and cardiometabolic indicators (blood pressure, fasting blood glucose, lipid profiles) were measured. Multivariate logistic regression was used to analyze the association between logOPA quartiles (Q1-Q4) and abnormal cardiometabolic indicators, while restricted cubic spline (RCS) models were employed to explore their dose-response relationships. Subgroup and interaction analyses were also conducted by gender. Results The median OPA of all participants was 12.86 MET·h·d⁻¹ (male: 14.40 MET·h·d⁻¹, female: 11.14 MET·h·d⁻¹). After adjusting for confounders, compared with the Q1 group, logOPA in the Q4 group was associated with 20% (OR=0.80, 95%CI: 0.72, 0.89), 14% (OR=0.86, 95%CI: 0.78, 0.96), and 13% (OR=0.87, 95%CI: 0.79, 0.95) reduction in the risk of abdominal obesity, low high-density lipoprotein cholesterol (HDL-C), and metabolic syndrome (MS), respectively, and 33% (OR=1.33, 95%CI: 1.18, 1.49), 33% (OR=1.33, 95%CI: 1.18, 1.50), and 38% (OR=1.38, 95%CI: 1.21, 1.57) increase in the risk of high total cholesterol (TC), high low-density lipoprotein cholesterol (LDL-C), and high non-HDL-C, respectively. Similar trends were observed in males and females, with significant positive associations of logOPA with high TC and high non-HDL-C in males (P_interaction<0.05). The risk of low HDL-C decreased rapidly when logOPA was more than 2.213 (OPA>9.14 MET·h·d⁻¹), showing an inverted L-shaped trend. The risk of high TC, high LDL-C, and high non-HDL-C increased beyond logOPA thresholds of 3.244, 2.476, and 3.377 (OPA >25.64, 11.89, and 29.28 MET·h·d⁻¹), respectively, showing a J-shaped trend. However, logOPA exhibited a U-shaped nonlinear dose-response relationship with blood pressure and fasting blood glucose abnormalities (P_non-linear<0.05) , with minimal risks at logOPA 2.969 and 2.372 (OPA of 19.47 and 10.72 MET·h·d⁻¹). Conclusion OPA exhibits heterogeneous dose-response patterns across cardiometabolic indicators. Integrating the inverted L-, J-, and U-shaped association patterns, we suggest an optimal OPA range of 9.14−25.64 MET·h·d⁻¹ for multiple cardiometabolic indicators in total individuals at high-risk of CVD, with ranges of 9.61−31.34 MET·h·d⁻¹ for males and 8.97−22.87 MET·h·d⁻¹ for females. These findings provide critical evidence for developing OPA interventions strategies targeting high-risk population for CVD.

Objective The study aimed to investigate whether montelukast sodium could alleviate airway inflammatory responses in asthmatic mice by affecting the PHD2/HIF-1α pathway.Methods An allergic asthma model was established by ovalbumin(OVA)induction,and 18 female BALB/c mice were randomly divided into a control group(Con group),an asthma group(OVA group),and an asthma group with montelukast sodium intervention(30 mg/kg montelukast sodium by oral administration 1 h before OVA challenge,Mon group).HE staining was used to analyze the pathological changes in the lungs of mice.Blood cell analyzer and kits were used to determine the number of inflammatory cells and the levels of cytokines,the content of lactic acid and pyruvic acid in the lungs,respectively.RT-PCR and Western blot were used to detect the mRNA and protein expression of HIF-1α,PHD2,E-cad and p120 in the lungs of mice.Results Compared with the Con group,there was a significant increase in the number of eosinophils,lymphocytes,neutrophils and monocytes,the levels of IL-5,IL-13,complement factor D(CFD)and contents of lactate and pyruvate in the lungs of mice in the OVA group.Lung HIF-1α,PHD2,p120 and E-cad mRNA levels were reduced,meanwhile HIF-1α and PHD2 protein expression were upregulated but E-cad and p120 protein expression were downregulated(all with P<0.05).After montelukast sodium intervention,the number of eosinophils and monocytes and CFD expression were significantly decreased in the lungs of Mon group,the contents of lactate and pyruvate were basically restored to normal,and the mRNA and protein expression of HIF-1α,PHD2,p120 and E-cad were effectively improved.Conclusion Montelukast sodium could alleviate the airway inflammatory responses in the lungs of asthmatic mice by regulating the PHD2/HIF-1α signaling pathway.

To evaluate the modification of allergic dermatitis on the association between PM exposure and allergic rhinitis in preschool children. This cross-sectional study was based on a questionnaire conducted between June 2019 and June 2020 to caregivers of children aged 3 to 6 years in the kindergartens of 7 Chinese cities to collect information on allergic rhinitis and allergic dermatitis. A mature machine learning-based space-time extremely randomized trees model was applied to estimate early-life, prenatal, and first-year exposure of PM 1, PM 2.5 and PM 10 at 1 km×1 km resolution. A combination of multilevel logistic regression and restricted cubic spline functions was used to quantitatively assess whether allergic dermatitis modifies the associations between size-specific PM exposure and the risk of childhood allergic rhinitis. The results showed that out of 28 408 children, 14 803 (52.1%) were boys and 13 605 (47.9%) were girls; the age of children ranged from 3.1 to 6.8 years, with a mean age of (4.9±0.9) years, of which 3 586 (12.6%) were diagnosed with allergic rhinitis. Among all children, 17 832 (62.8%) were breastfed for more than 6 months and 769 (2.7%) had parental history of atopy. A total of 21 548 children (75.9%) had a mother with an educational level of university or above and 7 338 (29.6%) had passive household cigarette smoke exposure. The adjusted ORs for childhood allergic rhinitis among the children with allergic dermatitis as per interquartile range (IQR) increase in early-life PM 1(9.8 μg/m 3), PM 2.5 (14.9 μg/m 3) and PM 10 (37.7 μg/m 3) were significantly higher than the corresponding ORs among the children without allergic dermatitis [ OR: 1.45, 95% CI (1.26, 1.66) vs. 1.33, 95% CI (1.20, 1.47), for PM 1; OR: 1.38, 95% CI (1.23, 1.56) vs. 1.32, 95% CI (1.21, 1.45), for PM 2.5; OR: 1.56, 95% CI (1.31, 1.86) vs. 1.46, 95% CI (1.28, 1.67), for PM 10]. The interactions between allergic dermatitis and size-specific PM exposure on childhood allergic rhinitis were statistically significant ( Z value=19.4, all P for interaction<0.001). The similar patterns were observed for both prenatal and first-year size-specific PM exposure and the results of the dose-response relationship were consistent with those of the logistic regression. In conclusion, allergic dermatitis, as an important part of the allergic disease progression, may modify the association between ambient PM exposure and the risk of childhood allergic rhinitis. Children with allergic dermatitis should pay more attention to minimize outdoor air pollutants exposure to prevent the further progression of allergic diseases.

To evaluate the modification of allergic dermatitis on the association between PM exposure and allergic rhinitis in preschool children. This cross-sectional study was based on a questionnaire conducted between June 2019 and June 2020 to caregivers of children aged 3 to 6 years in the kindergartens of 7 Chinese cities to collect information on allergic rhinitis and allergic dermatitis. A mature machine learning-based space-time extremely randomized trees model was applied to estimate early-life, prenatal, and first-year exposure of PM 1, PM 2.5 and PM 10 at 1 km×1 km resolution. A combination of multilevel logistic regression and restricted cubic spline functions was used to quantitatively assess whether allergic dermatitis modifies the associations between size-specific PM exposure and the risk of childhood allergic rhinitis. The results showed that out of 28 408 children, 14 803 (52.1%) were boys and 13 605 (47.9%) were girls; the age of children ranged from 3.1 to 6.8 years, with a mean age of (4.9±0.9) years, of which 3 586 (12.6%) were diagnosed with allergic rhinitis. Among all children, 17 832 (62.8%) were breastfed for more than 6 months and 769 (2.7%) had parental history of atopy. A total of 21 548 children (75.9%) had a mother with an educational level of university or above and 7 338 (29.6%) had passive household cigarette smoke exposure. The adjusted ORs for childhood allergic rhinitis among the children with allergic dermatitis as per interquartile range (IQR) increase in early-life PM 1(9.8 μg/m 3), PM 2.5 (14.9 μg/m 3) and PM 10 (37.7 μg/m 3) were significantly higher than the corresponding ORs among the children without allergic dermatitis [ OR: 1.45, 95% CI (1.26, 1.66) vs. 1.33, 95% CI (1.20, 1.47), for PM 1; OR: 1.38, 95% CI (1.23, 1.56) vs. 1.32, 95% CI (1.21, 1.45), for PM 2.5; OR: 1.56, 95% CI (1.31, 1.86) vs. 1.46, 95% CI (1.28, 1.67), for PM 10]. The interactions between allergic dermatitis and size-specific PM exposure on childhood allergic rhinitis were statistically significant ( Z value=19.4, all P for interaction<0.001). The similar patterns were observed for both prenatal and first-year size-specific PM exposure and the results of the dose-response relationship were consistent with those of the logistic regression. In conclusion, allergic dermatitis, as an important part of the allergic disease progression, may modify the association between ambient PM exposure and the risk of childhood allergic rhinitis. Children with allergic dermatitis should pay more attention to minimize outdoor air pollutants exposure to prevent the further progression of allergic diseases.