Occupational noise-induced hearing loss (ONIHL) is a global public health problem; occupational noise deafness is the second most prevalent occupational disease in China. A China-contextualized ONIHL prevention and control system has not yet established. In this issue, the column "Noise kurtosis adjustment and prevention and control of occupational hearing loss" introduced a preliminary study on developing a statistical distribution table of hearing threshold deviation values for otologically normal Chinese population, revealed the role of C-weighted kurtosis in assessing occupational hearing loss, and put forward the effect threshold of kurtosis for occupational hearing loss caused by non-steady noise. The adjustment terms and adjustment coefficients of the kurtosis-adjusted equivalent sound level estimated by nonlinear regression were explored, and the research progress on epidemiological characteristics of ONIHL based on temporal structure (kurtosis), theoretical research, and key technologies for prevention and control and their applications in China were outlined. Research suggestions were proposed regarding theoretical research, mechanism research, technology creation, cohort study, and standard formulation and revision.

Kurtosis reflecting noise's temporal structure is an effective metric for evaluating noise-induced hearing loss (NIHL), and its threshold is still unclear.ObjectiveTo explore the energy range of kurtosis and the threshold of NIHL induced by kurtosis in this energy rangeMethodsUsing cross-sectional design, 4 631 noise-exposed workers in manufacturing industry were selected. The hearing loss and noise exposure data of each worker were collected. Logistic regression model was used to establish the dose-response relationship between noise exposure and hearing loss and estimate the range of energy effects. Restricted cubic spline model was utilized to analyze the dose-response relationship curves of kurtosis to noise-induced hearing loss (NIHI) and high-frequency noise-induced hearing loss (HFNIHL) under different 8 h equivalent sound levels (LEX,8 h), as well as to estimate the kurtosis effect threshold.ResultsThe logistic regression model analysis showed that the prevalence of NIHI and HFNIHL increased significantly with increase of LEX,8 h for steady noise; when LEX,8 h of non-steady noise was 80-100 dB(A), the risk of hearing loss increased with an increase in kurtosis (P<0.05). The restricted cubic spline model showed that when LEX,8 h of non-steady noise was 0-80 dB(A) or > 100 dB(A), there was no significant relationship between kurtosis and NIHI or HFNIHL. When LEX,8 h was 80-100 dB(A), there was a significant nonlinear dose-response relationship between kurtosis and NIHL or HFNIHL (P<0.001), and kurtosis > 28.08 exerted effect in elevating NIHI or HFNIHL.ConclusionThe effect threshold of kurtosis on NIHL is 28.08 when non-steady noise levels are in the range of 80-100 dB(A). The effect threshold of kurtosis needs further verification.

Noise-induced hearing loss (NIHL) is a prevalent occupational health problem in workplace settings, with non-steady noise exposure being particularly widespread. Although kurtosis-adjusted equivalent sound level (L′EX,8 h) methods based on linear regression are available to assess hearing damage, the complexity of kurtosis effects necessitates introducing new metrics through nonlinear regression to improve predictive accuracy for hearing loss from non-steady noise exposure.ObjectiveTo examine the adjustment terms [lg(N/G)] and coefficients () of L′EX,8 h using nonlinear regression and evaluate the method's effectiveness in assessing occupational hearing loss associated with non-steady noise exposure.MethodsA cross-sectional study design was employed, enrolling 1 034 manufacturing workers and evaluating noise exposure to estimate hearing loss metrics. Quantile regression analysis quantified the proportional contributions of influencing factors for noise-induced permanent threshold shift at 3, 4, and 6 kHz frequencies (NIPTS346). L′EX,8 h was computed using multiple linear regression and nonlinear least squares optimization. Paired t-tests analyzed predictive efficacy before and after kurtosis adjustment to evaluate its impact on ISO 1999 NIPTS346 predictions. Chow tests compared the similarity of logistic regression curves for high-frequency noise-induced hearing loss (HFNIHL) incidence between non-steady noise (L′EX,8 h) and steady noise (LEX,8 h), thereby validating the effectiveness of L′EX,8 h.ResultsThe quantile regression analysis showed that kurtosis was a significant indicator of occupational hearing loss risk from non-steady noise (contribution rate was 27.5%, P<0.05). The linear regression and nonlinear least squares methods obtained six different combinations of coefficients () and adjustment terms [lg(N/G)]. Incorporating these L′EX,8 h adjustments into the ISO 1999 predictive model significantly reduced NIPTS underestimation (from 14.2 dB HL with LEX,8 h to 11.5–5.6 dB HL with L′EX,8 h, P<0.001). The model L′EX,8 h,6=LEX,8 h+7.9lg(N/10) achieved the most significant improvement, reducing underestimation by 8.7 dB HL. The logistic curve analysis further demonstrated that all L′EX,8 h dose-response relationships for non-steady noise aligned more closely with the steady noise group than LEX,8 h, with L′EX,8 h,6 showing the smallest divergence (difference: 4.1%).ConclusionsL′EX,8 h demonstrates superior efficacy in assessing the risk of occupational hearing loss induced by non-steady noise exposure. The L′EX,8 h metric, constructed by calculating adjustment terms and coefficients through nonlinear regression analysis, exhibits greater effectiveness than linear regression methods in evaluating occupational hearing loss associated with non-steady noise exposure.

Temporal kurtosis (without frequency weighting, i.e., Z-weighted kurtosis) can evaluate noise-induced hearing loss (NIHL). However, few studies have considered the function of frequency weighting (A- or C-weighted) kurtosis on NIHL.ObjectiveTo study the significance of A- and C-weighted kurtosis adjustment for equivalent sound level (L′EX,8 h) in evaluating occupational hearing loss.MethodsA cross-sectional survey was used to select 973 noise-exposed workers in seven industries as the subjects. The noise exposure of all workers was assessed by distributions of A-, C-, and Z-weighted kurtosis (e.g., KA, KC, and KZ) and respective adjusted equivalent sound level (e.g., L′EX,8 h-KA, L′EX,8 h-KC, and L′EX,8 h-KZ). The significance of A- and C-weighted kurtosis in evaluating NIHL was evaluated by correlations between three types of L′EX,8 h and NIHL, and improvement of noise-induced permanent threshold shift (NIPTS) underestimation predicted by the ISO prediction model (Acoustics—Estimation of noise-induced hearing loss, ISO 1999-2013).ResultsThe median KA, KC, and KZ were 68.33, 28.22, and 19.82, respectively. The binary logistic regression showed that LEX,8 h-KA, LEX,8 h-KC, and L′EX,8 h-KZ were risk factors for NIHL (OR>1, P<0.001). The receiver operating characteristic (ROC) curve showed that when the outcome variable was noise-induced hearing impairment (NIHI), the areas under the curves corresponding to L′EX,8 h-KA, L′EX,8 h-KC, and L′EX,8 h-KZ were 0.625, 0.628, and 0.625, respectively. When the outcome variable was high-frequency noise-induced hearing loss (HFNIHL), the areas under the curves corresponding to L′EX,8 h-KA, L′EX,8 h-KC, and L′EX,8 h-KZ were 0.624, 0.623, and 0.622, respectively (P<0.05). The order of underestimation improvement values predicted by L′EX,8 h for NIPTS1234 was: L′EX,8 h-KA (4.68 dB HL)>L′EX,8 h-KC (4.38 dB HL)>L′EX,8 h-KZ (4.28 dB HL) (P<0.001). The order of underestimation improvement values predicted by L′EX,8 h-K for NIPTS346 was: L′EX,8 h-KA (7.20 dB HL)>L′EX,8 h-KC (6.83 dB HL)>L′EX,8 h-KZ (6.71 dB HL) (P<0.001).ConclusionThe adjustment of A- and C-weighted kurtosis to equivalent sound level LEX,8 h can effectively improve the accuracy of the ISO 1999 prediction model in NIPTS prediction, and compared with the C-weighted, the A-weighted kurtosis can improve the result of the ISO 1999 prediction model in terms of underestimating NIPTS.

Current assessment of noise-induced hearing loss relies on the hearing threshold statistical distribution table of ISO 7029-2017 standard (ISO 7029), which is based on foreign population data and lacks a hearing threshold distribution table derived from pure-tone audiometry data of the Chinese population, hindering accurate evaluation of hearing loss in this group.ObjectiveTo establish a statistical distribution table of hearing threshold level (HTL) for otologically normal Chinese adults and to provide a scientific basis for revising the diagnostic criteria of occupational noise-induced deafness in China.MethodsA total of 1 271 otologically normal Chinese adults aged 18-60 years were divided into four groups with 10-year age intervals. Based on the pure tone audiometry data and power function operation formula, the relevant parameters of the median and percentile calculation formula of ISO 7029 were adjusted. Based on the adjusted parameters, a statistical distribution table of HTL of normal Chinese adults in otology was preliminarily constructed according to the calculation formula of ISO 7029. A nonparametric rank sum test was used to compare the difference between the adjusted median deviation value and the ISO 7029 calculation.ResultsExcept for a few frequencies (2 000, 3 000, and 8 000 Hz), the value of parameter adjusted for the auditory threshold deviation of the Chinese population (CHN-md) increased with the increase of frequency, while the value of parameter adjusted for the auditory threshold deviation of the Chinese population (CHN-md) decreased with the increase of frequency. The preliminary distribution table of otologically normal Chinese adults' median hearing threshold deviation (HCHN-md) showed that the hearing threshold deviation increased with age and frequency. At 8 000 Hz, the increase in HCHN-md with age was the greatest for both men and women, from 0 dB to 23 dB and 21 dB respectively. The minimal threshold elevation was noted at 500, 1 000, and 2 000 Hz, which increased from 0 dB to 2 dB. In otologically normal Chinese adults, the maximum increase of HCHN-md with frequency was observed at age of 50 years, which increased from 2 dB at 500 Hz to 23 dB at 8 000 Hz in men and from 2 dB at 500 Hz to 21 dB at 8 000 Hz in women. The comparison results with the ISO 7029 calculation showed that the trend was consistent. The median hearing threshold deviation value of the adjusted Chinese population was lower than that of the ISO 7029 calculation (Hmd). However, they had no significant statistical difference (P>0.05). For otologically normal normal Chinese men and women, the maximum difference of Hmd between the 50-year-old group and the ISO calculation at 8 000 Hz was 7 dB and 9 dB, respectively.ConclusionThis preliminary analysis of hearing threshold deviations in otologically normal Chinese adults suggests that current standards may potentially underestimate hearing loss at frequencies below 8 000 Hz while possibly overestimating it at 8 000 Hz. These findings require further validation through expanded sample sizes to more accurately assess the characteristics of hearing thresholds in the Chinese population and their discrepancies with existing standards.

The impact of cold spells on population health can be categorized into an independent main effect of extreme low temperatures and an added effect of prolonged low temperatures. However, studies on the added effects of cold spells on hospitalizations remain limited.ObjectiveTo investigate the added effects of cold spells on hospitalizations of residents in Hengyang City, Hunan Province, and to provide a scientific basis for establishing a cold spell early warning system.MethodsDaily meteorological data, air pollutant data, and hospitalization data from six tertiary hospitals of four districts in Hengyang City from 2017 to 2023 were collected. A generalized linear model (GLM) combined with a distributed lag nonlinear model (DLNM) was used to assess the added effects of cold spells on non-accidental hospitalizations, as well as hospitalizations for circulatory system diseases and respiratory system diseases, after controlling the main effect of temperature. The modifying effects of cold spell characteristics (intensity and duration) and individual characteristics (gender and age) were also analyzed.ResultsCompared with non-cold spell periods, the relative risks (RRs) of total non-accidental hospitalizations and hospitalizations across disease categories, genders, and age groups were elevated during cold spells of varying intensities and durations. However, the total effects of cold spells exhibited a "U-shape" nonlinear relationship with intensity and decreased with prolonged duration. During high-intensity cold spells (daily average temperature < P5 and lasting ≥ 2 d), the RR (95%CI) for non-accidental hospitalizations was 1.71 (1.21, 2.42); the RRs (95%CIs) for males and females were 1.99 (1.38, 2.84) and 1.47 (1.00, 2.16), respectively; for individuals < 65 years and ≥ 65 years, the RRs (95%CIs) were 1.59 (1.12, 2.26) and 1.93 (1.27, 2.92), respectively; and for circulatory and respiratory system diseases, the RRs (95%CIs) were 1.84 (1.22, 2.79) and 1.07 (0.71, 1.60), respectively. No statistically significant differences were observed between the above subgroups. The single-day lagged effects of cold spells displayed a two-peaked pattern. The single-day lag RR for total non-accidental hospitalizations peaked at lag 1 d after cold spell exposure, declined thereafter, and began to rise again after lag 5 d, reaching a second peak at lag 12–13 d before gradually decreasing. The lagged effects remained statistically significant during lag 8–18 d. The lag patterns of cold spell associations across disease categories, genders, and age groups were largely consistent with those of total hospitalizations.ConclusionCold spells have a significant impact on non-accidental hospitalizations of residents in Hengyang City, with notable lagged effects. The findings provide important theoretical support for establishing a more targeted cold spell early warning system.

Diesel engines are widely used in transportation, agriculture, construction, industry, and other fields. Diesel exhaust, classified as a Group 1 carcinogen, emits particles (DEP) that can penetrate deep into the respiratory tract, posing significant health risks. DEP pollution is particularly severe in confined environments, necessitating effective control measures.ObjectiveUnder laboratory simulation conditions, to explore the spatiotemporal distribution characteristics of the mass and number concentrations of DEP as it diffuses indoors and to reveal the effects of ventilation and additional airflow on indoor DEP pollution levels.MethodsA diesel engine was placed in a laboratory (length 3.39 m × width 2.85 m × height 2.4 m) with its exhaust emitted from east to west. An air purifier was installed 1 m south of the engine. Eight measurement points (1 m horizontal distance from the exhaust outlet, height: 1 m/1.5 m) were setup to monitor DEP concentrations using portable laser particle sizers. The effects of engine power (4.05 kW vs. 5.15 kW), ventilation (maximum airflow: 600 m3·h&#x2212;1), additional airflow intensity (low and high), and direction (forward/reverse) on DEP pollution were analyzed. DEP levels of 5 diesel vehicle models were also compared.ResultsThe mass and number concentrations of DEP indoors increased immediately after the diesel engine started. The peak mass concentration time at the eastern measurement point (&#x2212;1, 0) m opposite to the exhaust direction (17.70 min) was significantly longer than that at the western (1, 0) m (16.20 min), southern (0, -1) m (14.45 min), and northern (0, 1) m (12.70 min) points (P<0.05), with no significant differences between the other points (western, southern, and northern) (P>0.05). The northern point (0, 1) m exhibited the highest DEP mass and number concentration peaks (174.62 g·m&#x2212;3, 1 319.85 p·cm&#x2212;3), significantly exceeding those at the southern (0, &#x2212;1) m (129.89 g·m&#x2212;3, 1 175.24 p·cm&#x2212;3), eastern (&#x2212;1, 0) m (140.12 g·m&#x2212;3, 1 120.53 p·cm&#x2212;3), and western (1, 0) m (147.60 g·m&#x2212;3, 818.62 p·cm&#x2212;3) points (P<0.05), and no significant differences were observed among other points (P>0.05). There were no significant differences in peak DEP mass and number concentrations by measurement heights (P>0.05). Diesel engine power, ventilation, airflow intensity, and airflow direction had no significant effect on the time of peak DEP concentration (P>0.05). However, higher engine power (5.15 kW) produced greater DEP peaks [(186.66±19.29) g·m&#x2212;3, (1 382.79±122.56) p·cm&#x2212;3] than the 4.05 kW engine power [(168.41± 12.65) g·m&#x2212;3, (1 284.45±71.30) p·cm&#x2212;3] (P<0.05). The peak mass concentration [(342.04±35.03) g·m&#x2212;3] and number concentration [(1 886.87±57.91) p·cm&#x2212;3] of DEP in the non-ventilated group were significantly higher than those in the ventilated group [(186.66± 19.29) g·m&#x2212;3, (1 382.79±122.56) p·cm&#x2212;3] (P<0.001). Forward airflow elevated DEP mass concentrations compared to reverse airflow (287.71 g·m&#x2212;3 vs. 243.74 g·m&#x2212;3, t=&#x2212;2.592, P=0.009), but no effects on DEP number concentration (P>0.05). Significant differences in mass concentration were observed among selected 5 vehicle models (Z=38.109, P<0.001).ConclusionThe operation of diesel engines will emit a large amount of particulate matter, causing pollution in enclosed spaces. Diesel engines with greater power have higher levels of DEP pollution emissions. Based on the spatiotemporal distribution characteristics, it is recommended to set the operation position in the reverse direction of exhaust emissions and close to air purifiers, while avoiding the use of additional air flow equipment.

Occupational disease diagnosis appraisal is an appeal procedure initiated when a party disagrees with the occupational disease diagnosis conclusion. It is a legal procedure to safeguard the health rights of employees and the legitimate rights and interests of employers.ObjectiveTo analyze the data of occupational disease diagnosis appraisal in Shanghai, identify existing problems, and provide suggestions for improving.MethodsStatistical analysis was conducted on basic situation, characteristics of workers and employers, disease classification, and consistency between diagnosis and appraisal conclusions of all occupational disease diagnosis appraisal cases from 2012 to 2024. All diagnosis conclusions were named in accordance with the Classified Catalogue of Occupational Diseases included employers were classified according to the Measures for the Statistical Classification of Large, Medium, Small and Micro Enterprises" and the Notice on Adjusting the Provisions for Classifying Enterprise Registration Types; industry classification followed the Industrial Classification for National Economic Activities (GB/T 4754-2017).ResultsFrom 2012 to 2024, a total of 260 cases of occupational diseases diagnosis appraisal were closed. The main diagnosis were 138 cases of ear, nose, throat, and oral diseases (53.1%), chemical poisoning (18.8%), and pneumoconiosis and other respiratory diseases (16.2%). The proportion of ear, nose, throat, and oral diseases gradually increased (2022 excluded). The incidence of annual municipal and provincial cases decreased by 76.3% and 85.0% respectively (2024 vs 2012). The consistency rate of conclusions between appraisal and diagnosis gradually increased. The total consistency rates between final appraisals and diagnostic conclusions were 81.5%, and 79.7%, 87.8%, 100.0%, 85.0% for ear, nose, throat, and oral diseases, chemical poisoning, and pneumoconiosis and other respiratory system diseases, respectively. Specifically, the consistency rates were 80.1% and 80.0% for noise-induced deafness and chronic benzene poisoning. In terms of inconsistency reasons, "inconsistent interpretation of standards and excessive discretion in standard application" accounted for 43.8%, followed by "failure to correctly apply standards" (31.3%) and and "discrepancies in occupational exposure history recognition" (15.6%).ConclusionThe revisions and improvements of the legal system for occupational disease diagnosis appraisal have played a positive role in improving the consistency of conclusions between appraisal and diagnosis of occupational diseases in Shanghai. It is suggested to further strengthening the publicity and training of occupational disease diagnosis standards to improve the quality of occupational disease diagnosis.

With economic development and globalization, shift work has become prevalent across industries. Its relationship with type 2 diabetes mellitus (T2DM) attracts increasing attention.ObjectiveTo thoroughly explore the relationship between shift work and T2DM, and analyze the impacts of specific shift patterns on T2DM, so as to provide a basis for formulating reasonable shift schedules.MethodsWe conducted a 1:2 matched case-control study among adults (20-60 years) who ordered occupational health examinations at the Wuxi No.8 People's Hospital from November to December 2023. The case group comprised 200 T2DM patients, while the controls were 400 agestratified matched non-diabetic individuals. General demographic characteristics, behavioral habits, medical history, and shift work exposure data (including shift patterns, frequency, and length of service) 5 years prior to diagnosis were collected through standardized questionnaires. Logistic regression adjusted for selected confounders was employed to evaluate the association between shift work and T2DM.ResultsThe logistic regression analysis demonstrated that shift work was associated with an increased risk of T2DM. After adjusting for confounding factors, shift workers had a 3.55 times higher risk of being diagnosed T2DM compared to non-shift workers (OR=3.55, 95%CI: 1.026, 12.263). The risk varied across different shift patterns, and the three-shift two-rotation system showed the highest risk (OR=4.17, 95%CI: 1.921, 9.035), followed by the two-shift system (OR=2.94, 95%CI: 2.016, 4.281) and four-shift three-rotation system (OR=2.66, 95%CI: 1.611, 6.093). Workers with more than 3 monthly shift days had a 2.74-fold increased risk (95%CI: 1.658, 4.512) compared to non-shift workers. Additionally, working more than 8 h daily (OR=1.74, 95%CI: 1.185, 2.562) and having more than 20 years of service (OR=2.51, 95%CI: 1.581, 3.976) were both significantly associated with a higher T2DM risk. The trend tests revealed that each incremental increase in monthly shift days and length of service elevated T2DM risk by 2.61 times (95%CI: 1.813, 3.765) and 1.49 times (95%CI: 1.147, 1.931), respectively (P<0.05).ConclusionShift work is an independent risk factor for T2DM, with three-shift two-rotation system posing the highest risk. Shift frequency, daily working hours, and length of service are all significant factors affecting the risk of T2DM. These findings support industry-specific shift policy reform and targeted glucose monitoring and health interventions are recommended for workers engaged in high-risk shift patterns (e.g., three-shift two-rotation system, frequent shifts) and those with prolonged shift work history (>20 years).

Enhancing the sense of honor and belonging among medical staff is a key component of establishing a modern hospital management system. Compared to medical staff at general hospitals, medical staff at oncology hospitals are more prone to job burnout, yet few studies in China have focused on job burnout among employees in oncology hospitals.ObjectiveTo propose a hypothetical model in which job well-being moderates the relationship between stressors and occupational burnout, to explore how stressors influence burnout and potential moderating role of job well-being, and to provide better understanding of job burnout and motivate employees based on the double-edge sword effect of stressors.MethodsA cross-sectional survey was conducted in May 2022 at a tertiary oncology specialty hospital in Chongqing, China. A total of 1 898 medical staff were recruited. Data were collected through four scales including a general information questionnaire, Maslach Burnout Inventory-Human Service Survey, Work Stressor Scale, and Occupational Well-being Scale for Medical Staff. Independent sample t-tests and one-way ANOVA were used for univariate comparisons of job burnout. Pearson correlation analysis was employed to examine the relationships between job burnout, stressors, and job well-being. Hierarchical linear regression was conducted to identify factors influencing job burnout and to examine potential moderating role of job well-being in the relationship between stressors and job burnout.ResultsA total of 2 123 questionnaires were distributed, with 1 898 valid responses, yielding an effective response rate of 89.4%. The prevalence of job burnout was 60.1%. The correlation coefficient was 0.717 (P<0.001) between stressors and burnout, &#x2212;0.784 (P<0.05) between job well-being and burnout, and &#x2212;0.744 (P<0.001) between stressors and job well-being. The quadratic stressors showed a statistically significant effect on burnout (=0.404, P<0.01). Job well-being positively moderated the relationship between the linear stressors and burnout (=1.289, P<0.001) and negatively moderated the relationship between the quadratic stressors and job burnout (=&#x2212;0.571, P<0.01), explaining 7.1% of the variance.ConclusionJob burnout prevalence is relatively high among employees in oncology hospitals. There is a curvilinear relationship between stressors and job burnout, with job well-being moderating this relationship. From a practical perspective, it is recommended to establish a tiered stress alert system to monitor employees' stress levels and prevent prolonged exposure to high-pressure conditions. Additionally, improving employees' job well-being through institutional incentives and developmental support can enhance its moderating role in mitigating the adverse effects of stressors on job burnout. Meanwhile, fostering coordinated responses between organizations and individuals is crucial for strengthening mental health management systems, thereby supporting a healthy, stable, and sustainable development of the healthcare workforce.

Existing studies suggest that cadmium exposure is associated with the occurrence of cardiovascular disease (CVD), but the current epidemiological evidence is inconsistent.ObjectiveTo systematically evaluate the relationship between cadmium exposure and CVD through meta-analysis.MethodsWe systematically searched PubMed, Cochrane Library, Web of Science, CNKI, Wanfang and SinoMed databases to collect observational studies on the relationship between cadmium exposure and CVD in human population published until July 30, 2024. On the basis of following predetermined inclusion and exclusion criteria, the retrieved literature was systematically screened, and the basic information of the included research was extracted, including basic participant information, research outcomes, and data results. This study used the Newcastle-Ottawa Scale and a cross-sectional study evaluation protocol (11 items) recommended by the Quality of Health Care and Research Institutions of the United States for literature quality evaluation. Meta-analysis, subgroup analysis, sensitivity analysis, and assessment of publication bias of the data were conducted using Stata16.0 software.ResultA total of 15 studies (18 datasets) were included, and the quality of all the studies was graded as medium or above. Among them, there were 10 593 cases of CVD and 86 801 controls. The results of meta-analysis showed that the standard mean difference (SMD) of the CVD case group was 0.44 and 95% confidence interval (95%CI) was (0.30, 0.58), and the cadmium exposure level of the CVD case group was higher than that of the control group (P<0.05). The subgroup analysis showed that the cadmium exposure levels in the CVD patients from the Americas (SMD=0.46, 95%CI: 0.29, 0.63) and Europe (SMD=0.14, 95%CI: 0.09, 0.19) were higher than those in the control group (P<0.05). The cadmium levels in blood (SMD=0.52, 95%CI: 0.31, 0.73) and urine (SMD=0.34, 95%CI: 0.16, 0.52) in the CVD case group were higher than those in the control group (P<0.05). In those cross-sectional studies (SMD=0.34, 95%CI: 0.23, 0.46), the cadmium exposure level in the CVD patients was higher than that in the control group (P<0.05). The sensitivity analysis showed robust meta-analysis results and the assessment of publication bias also showed no publication bias.ConclusionCadmium exposure may increase the risk of cardiovascular disease after multiple studies were combined by meta analysis, suggesting that the scope and level of cadmium exposure in the population should be further controlled.

Currently, incidents of organic solvent poisoning are occurring frequently. Rapidly and accurately qualitative and quantitative analysis of toxic substances is crucial for the treatment of affected individuals. In recent years, many biomarker assays with good specificity and high sensitivity have been developed for the detection of exposure to organic solvents, but they cannot meet the demand for real-time and fast detection.ObjectiveTo establish a paper spray mass spectrometry method for direct and rapid detection of four organic compound metabolites (toluene diamine, 2, 5-hexanedione, hippuric acid, and methylhippuric acid) in the urine of occupational populations.MethodsToluene diamine and 2, 5-hexanedione were analyzed using positive ion mode, while hippuric acid and methylhippuric acid were analyzed using negative ion mode. The ion transfer tube temperature was 275 °C. The ion transfer tube voltage was 35 V. For positive ion mode, the scan range was 50-150 m/z. For negative ion mode, the scan range was 150-250 m/z. The distance from the paper substrate tip to the mass spectrometry inlet was 8 mm. The applied voltage was 3.5 kV. The spray solvent was methanol/water (90:10). The spray solvent volume was 15 L. Under the optimized experimental conditions, both external standard and internal standard methods were used for quantitative analysis. Limit of detection, limit of quantification, accuracy, and precision of the proposed method were determined by spiking blank urine samples. To evaluate the feasibility of the method, the established approach was compared with current national standard detection methods or methods described in the literature. All methods were used to analyze 40 urine samples collected from occupationally exposed individuals (20 exposed to n-hexane and 20 exposed to toluene and xylene).ResultsThe four biomarkers showed good linearity within their respective measurement ranges and the correlation coefficients were higher than 0.999 0. The limits of detection of the method were in the range of 0.000 27 to 0.020 g·mL&#x2212;1, and the limits of quantification were in the range of 0.000 9 to 0.067 g·mL&#x2212;1. The spiked recoveries at low, medium, and high concentrations ranged from 96.5% to 106.9%, with relative standard deviations (RSDs) between 5.6% and 9.7%. When applying the method to 40 urine samples from occupationally exposed individuals, the detection rates for toluene diamine, 2, 5-hexanedione, hippuric acid, and methylhippuric acid were 0%, 45%, 20%, and 37.5%, respectively. For biomarkers detected by both this method and the reference methods, the detection values were generally consistent. The analysis time per sample was approximately 1-2 min using paper spray mass spectrometry, compared to 1-2 h for reference methods.ConclusionThe paper spray mass spectrometry method established in this study for detecting four organic compound metabolites in urine is characterized by its simplicity, rapidity, efficiency, and high accuracy. It can obtain results within 1-2 min, which significantly improves the timeliness of detection. It is suitable for direct and rapid screening of four organic compound metabolites in urine, and can provide technical support for the diagnosis and treatment of organic solution poisoning.

With the progression of industrialization, an increasing number of emerging contaminants are entering aquatic environments, posing significant threats to the safety of drinking water. Therefore, establishing a system for identifying unknown hazardous factors and implementing safety warning mechanisms for drinking water is of paramount importance. Among these efforts, non-target screening plays a critical role, but its effectiveness is largely constrained by the scope of coverage of sample pre-treatment methods.ObjectiveTo integrate modern chromatography/mass spectrometry techniques with advanced data mining methods to develop a non-discriminatory sample pre-treatment method for comprehensive enrichment of unknown contaminants in drinking water, laying a technical foundation for the discovery and identification of unknown organic hazardous factors in drinking water.MethodsA non-discriminatory pre-treatment method based on supramolecular and solid-phase extraction was developed. The final target compounds including 333 pesticides, 194 pharmaceuticals and personal care products (PPCPs), and 59 per- and polyfluoroalkyl substances (PFASs) were used for optimizing the pre-treatment method, confirming its coverage. The impacts of different eluents on the absolute recovery rates of target compounds were compared to select the conditions with the highest recovery for sample pre-treatment. The effects of different supramolecular solvents and salt concentrations on target compound recovery were also evaluated to determine the most suitable solvent and salt concentration.ResultsThe solid-phase extraction elution solvents, supramolecular extraction solvents, and salt concentrations were optimized based on the target compound recovery rates. The optimal recovery conditions were achieved using 2 mL methanol, 2 mL methanol (containing 1% formic acid), 2 mL ethyl acetate, 2 mL dichloromethane, hexanediol supramolecular solvent, and 426 mg salt. The detection method developed based on these conditions showed a good linear relationship for all target compounds in the range of 0.1-100.0 ng·mL&#x2212;1, with R2 > 0.99. The method's limit of detection ranged from 0.01 ng&#x2212;1 to 0.95 ng&#x2212;1, and 95% of target compounds were recovered in the range of 20%-120%, with relative standard deviation (RSD) less than 30%, indicating good precision.ConclusionThe combined pre-treatment method of solid-phase extraction and supramolecular solvent extraction can effectively enrich contaminants in drinking water across low, medium, and high polarities, enabling broad-spectrum enrichment of diverse trace contaminants in drinking water. It provides technical support for broad-spectrum, high-throughput screening and identification of organic pollutants in drinking water, and also serves as a reference for establishing urban drinking water public safety warning systems.

Bisphenols (BPs) are extensively used in food packaging, personal care products, and plastics, making them prevalent in both living and working environments, which has raised significant concern. As endocrine-disrupting chemicals, BPs exert toxic effects on the female reproductive system by binding to estrogen receptors, thereby activating or inhibiting the expression of genes related to reproductive functions, which disrupts the normal function of the endocrine system. This paper reviewed the effects of bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF) on female reproductive function, focusing on three key aspects: the effects on the female reproductive organs, the occurrence of associated reproductive disorders, and the mechanisms of toxicity. Specifically, this review highlighted the effects on ovarian function, uterine morphology and function, and fallopian tube function, as well as their correlation with polycystic ovary syndrome, endometriosis, miscarriage, and eclampsia. Additionally, the toxic mechanisms of BPs exposure were summarized, providing a scientific basis for future research on the impact of BPs on the female reproductive system, as well as for the assessment of potential health risks and the development of preventive measures.

Fluorine is a common chemical element. Excessive intake of fluoride can lead to fluorosis. Fluoride easily passes through the blood-brain barrier and accumulates in different brain regions, causing pathological changes in brain tissue. It leads to adverse effects on neuronal metabolism, enzyme, protein function, neurotransmitters, and redox homeostasis, and subsequently neuronal damage and neurodegenerative diseases in humans and experimental animals. This paper reviewed the effects and important mechanisms of fluoride on neurological function and behavior, involving mitochondrial toxicity, oxidative stress, cell apoptosis and autophagy, and activation of pro-inflammatory factors. It provided a reference for further studying the mechanisms of brain damage induced by fluorosis.

Infertility is a common reproductive disorder affecting millions of couples worldwide. It is estimated that male factors account for about 30%-50% of infertility cases, and some studies have found that the concentration of male sperm gradually decreases over time, a trend that suggests the importance of male fertility. Many factors contribute to the decline of male fertility, among which environmental factors have received widespread attention. After reaching adulthood, spermatogonial stem cells will continue to produce sperm, but these cells exist outside the blood testicular barrier, which makes them highly sensitive to environmental conditions such as air pollution, tobacco smoke, radiation, and heavy metals. It is reported that exposure to these adverse environmental factors not only causes oxidative stress and DNA damage to germ cells, but also leads to abnormal epigenetic modification of sperm DNA, thereby causing a series of diseases. This article reviewed the abnormal methylation changes in DNA associated with exposure to environmental pollutants during spermatogenesis and how these changes affect the quantity, quality, and function of spermatozoa.

Fine particulate matter (PM2.5) is a critical environmental factor that currently affects human health. It primarily enters the body through inhalation and can induce adverse health effects in multiple systems, including respiratory, cardiovascular, nervous, and digestive systems. The homeostasis of gut microbiota is crucial for human health, and gut microbiota may exert multiple effects through the regulation of immune function, metabolic balance, and neural signal transmission. Recently, more and more studies have indicated that exposure to PM2.5 may alter the composition and richness of gut microbiota and play a crucial role in the development and progression of various diseases through multiple pathways. Given the close interaction between PM2.5 exposure and gut microbiota, we comprehensively reviewed the effects of ambient PM2.5 exposure on gut microbiota and the potential underlying mechanisms based on existing epidemiological and toxicological studies. Additionally, the role of gut microbiota in the adverse health effects induced by PM2.5 exposure, particularly in the context of gut-lung, gut-brain and gut-liver axis were also explored here.