BACKGROUND: Prolonged occupational noise exposure poses potential health risks, but its impact on mitochondrial DNA (mtDNA) damage and methylation patterns remains unclear. METHOD: We recruited 306 factory workers, using average binaural high-frequency hearing thresholds from pure-tone audiometry to assess noise exposure. MtDNA damage was evaluated through mitochondrial DNA copy number (mtDNAcn) and lesion rate, and mtDNA methylation changes were identified via pyrophosphate sequencing. RESULTS: There was a reduction in MT-RNR1 methylation of 4.52% (95% CI: -7.43% to -1.62%) among workers with abnormal hearing, whereas changes in the D-loop region were not statistically significant (β = -2.06%, 95% CI: -4.44% to 0.31%). MtDNAcn showed a negative association with MT-RNR1 methylation (β = -0.95, 95% CI: -1.23 to -0.66), while no significant link was found with D-loop methylation (β = -0.05, 95% CI: -0.58 to 0.48). Mediation analysis indicated a significant increase in mtDNAcn by 10.75 units (95% CI: 3.00 to 21.26) in those with abnormal hearing, with MT-RNR1 methylation mediating 35.9% of this effect. CONCLUSIONS These findings suggest that occupational noise exposure may influence compensatory increases in mtDNA content through altered MT-RNR1 methylation.
Humans ; DNA, Mitochondrial ; DNA Methylation ; Male ; Adult ; Noise, Occupational/adverse effects* ; Middle Aged ; Occupational Exposure/adverse effects* ; Biomarkers/blood* ; Female

OBJECTIVE: We aimed to investigate the patterns of fasting blood glucose (FBG) trajectories and analyze the relationship between various occupational hazard factors and FBG trajectories in male steelworkers. METHODS: The study cohort included 3,728 workers who met the selection criteria for the Tanggang Occupational Cohort (TGOC) between 2017 and 2022. A group-based trajectory model was used to identify the FBG trajectories. Environmental risk scores (ERS) were constructed using regression coefficients from the occupational hazard model as weights. Univariate and multivariate logistic regression analyses were performed to explore the effects of occupational hazard factors using the ERS on FBG trajectories. RESULTS: FBG trajectories were categorized into three groups. An association was observed between high temperature, noise exposure, and FBG trajectory ( P < 0.05). Using the first quartile group of ERS1 as a reference, the fourth quartile group of ERS1 had an increased risk of medium and high FBG by 1.90 and 2.21 times, respectively (odds ratio [ OR] = 1.90, 95% confidence interval [ CI]: 1.17-3.10; OR = 2.21, 95% CI: 1.09-4.45). CONCLUSION An association was observed between occupational hazards based on ERS and FBG trajectories. The risk of FBG trajectory levels increase with an increase in ERS.
Humans ; Male ; Adult ; Blood Glucose/analysis* ; China ; Prospective Studies ; Occupational Exposure/adverse effects* ; Risk Factors ; Middle Aged ; Steel ; Fasting/blood* ; Metal Workers ; East Asian People

Objective: To explore the change of hearing threshold of workers exposed to noise, establish an individual-based hearing loss early warning model, accurately and differentiated the health of workers exposed to noise. Methods: In September 2019, all physical examination data of 561 workers exposed to noise from an enterprise were collected since their employment. Three indicators of average hearing threshold of the better ear, namely, at high frequency, 4000 Hz and speech frequency, were constructed. The generalized estimating equation (GEE) was used to adjust gender and age and establish the warning model of each indicator. Finally, sensitive indicators and warning models were screened according to AUC and Yoden index. Results: Among the 561 workers exposed to noise, 26 (4.6%) workers had hearing loss. The sensitivity indicators were the average hearing threshold at speech frequency ≥20 dB, high frequency ≥30 dB and 4000 Hz ≥25 dB. The AUC of each index was 0.602, 0.794 and 0.804, and the Youden indexes were 0.204, 0.588 and 0.608, respectively. In GEE of hearing loss warning models, high-frequency hearing threshold ≥20 dB and 4000 Hz hearing threshold ≥25 dB were the optimal models, with AUC of 0.862. Conclusion: Combined with the changes of individual hearing threshold over the years, can accurately assess the risk of individual hearing loss of workers exposed to noise.
Humans ; Hearing Loss, Noise-Induced/diagnosis* ; Noise, Occupational/adverse effects* ; Audiometry ; Deafness ; Employment ; Occupational Exposure/adverse effects* ; Occupational Diseases/diagnosis*

Objective: To analyze correlation of occupational hydrogen fluoride exposure to low doses of bone metabolism index through occupational epidemiological investigation and benchmark dose calculation. Methods: In May 2021, using cluster sampling method, 237 workers exposed to hydrogen fluoride in a company were selected as the contact group, and 83 workers not exposed to hydrogen fluoride in an electronics production company were selected as the control group. The external exposure dose and urinary fluoride concentration, blood and urine biochemical indicators of the workers was measured.The relationship between external dose and internal dose of hydrogen fluoride was analyzed. The external dose, urinary fluoride was used as exposure biomarkers, while serum osteocalcin (BGP), serum alkaline phosphatase (AKP) and urinary hydroxyproline (HYP) were used as effect biomarkers for bone metabolism of hydrogen fluoride exposure. The benchmark dose calculation software (BMDS1.3.2) was used to calculate benchmark dose (BMD) . Results: Urine fluoride concentration in the contact group was correlated with creatinine-adjusted urine fluoride concentration (r=0.69, P=0.001). There was no significant correlation between the external dose of hydrogen fluoride and urine fluoride in the contact group (r=0.03, P=0.132). The concentrations of urine fluoride in the contact group and the control group were (0.81±0.61) and (0.45±0.14) mg/L, respectively, and the difference between the two groups was statistically significant (t=5.01, P=0.025). Using BGP, AKP and HYP as effect indexes, the urinary BMDL-05 values were 1.28, 1.47 and 1.08 mg/L, respectively. Conclusion: Urinary fluoride can sensitively reflect the changes in the effect indexes of biochemical indexes of bone metabolism. BGP and HYP can be used as early sensitive effect indexes of occupational hydrogen fluoride exposure.
Humans ; Fluorides/adverse effects* ; Hydrofluoric Acid ; Benchmarking ; Biomarkers ; Occupational Exposure/adverse effects*

Occupational exposure to diacetyl can lead to bronchiolitis obliterans. In this paper, two patients with severe obstructive ventilation disorder who were exposed to diacetyl at a fragrance and flavours factory were analyzed. The clinical manifestations were cough and shortness of breath. One of them showed Mosaic shadows and uneven perfusion in both lungs on CT, while the other was normal. Field investigation found that 4 of the 8 workers in the factory were found to have obstructive ventilation disorder, and 2 had small airway dysfunction. This paper summarizes the diagnostic process of patients in order to improve the understanding of airway dysfunction caused by occupational exposure to diacetyl and promote the development of relevant standards.
Humans ; Diacetyl/adverse effects* ; Occupational Diseases/diagnosis* ; Occupational Exposure/adverse effects* ; Lung ; Bronchiolitis Obliterans/diagnosis*

BACKGROUND: Few prospective studies have investigated the association between paternal occupational exposures and risk of infant congenital heart defects (CHDs). We investigated the associations between paternal occupational exposures, frequency of use, and concurrent or sequential exposure to a mixture of compounds and the risk of infant CHDs. METHODS: Our study examined 28,866 participants in the Japan Environment and Children's Study. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) associated with paternal occupational exposures during the 3 months until pregnancy was noticed after adjustment for potential confounding factors of the infant CHDs. CHD diagnosis was ascertained from medical record. RESULTS: In total, 175 were diagnosed with infant CHDs. The number of fathers who were exposed to the following substances at least once a month were: 11,533 for photo copying machine/laser printer, 10,326 for permanent marker, 8,226 for soluble paint/inkjet printer, 6,188 for kerosene/petroleum/benzene/gasoline, 4,173 for organic solvents, 3,433 for chlorine bleach/germicide, 2,962 for engine oil, 2,931 for insecticide, 2,460 for medical sterilizing disinfectant, 1,786 for welding fumes, 1,614 for dyestuffs, 1,247 for any products containing lead-like solder, 986 for herbicide, 919 for radiation/radioactive substances/isotopes, 837 for lead-free solder, 341 for microbes, 319 for formalin/formaldehyde, 301 for agricultural chemical not listed above or unidentified, 196 for general anesthetic for surgery at hospital, 171 for anti-cancer drug, 147 for chromium/arsenic/cadmium, 88 for mercury and 833 for other chemical substances. Paternal occupational exposure regularly to photo copying machine or laser printer and soluble paint/inkjet printer were associated with higher risks of infant CHDs: the adjusted ORs (95%CIs) were 1.38 (1.00-1.91) and 1.60 (1.08-2.37), respectively. The higher risks were also observed for occasional exposure to engine oil, any products containing lead-like solder lead-free solder, and microbes; the adjusted ORs (95%CIs) were 1.68 (1.02-2.77), 2.03 (1.06-3.88), 3.45 (1.85-6.43), and 4.51, (1.63-12.49), respectively. CONCLUSIONS Periconceptional paternal occupational exposure was associated with a higher risk of infant CHDs. Further studies using biomarkers of the association between paternal occupational exposure and infant CHDs are warranted.
Male ; Humans ; Infant ; Child ; Japan/epidemiology* ; Prospective Studies ; Risk Factors ; Case-Control Studies ; Occupational Exposure/adverse effects* ; Heart Defects, Congenital/epidemiology* ; Fathers

Objective: To analyze the case characteristics of Chronic obstructive pulmonary disease caused by occupational irritant chemicals (OI-COPD). To provide basis for revising its diagnostic criteria. Methods: From June to December 2021, we investigated the information of OI-COPD patients confirmed by Shandong Institute of Occupational Health and Prevention of Occupational Diseases, Guangxi Zhuang Autonomous Region Institute of Occupational Disease Prevention and Control, Qingdao Central Hospital affiliated to Qingdao University and other diagnostic institutions in the past five years, a total of 41 cases. The basic information of OI-COPD cases, occupational risk factors exposure information, medical history, smoking history and clinical symptoms were analyzed retrospectively. The measurement data were tested for normal distribution, which was described by x±s, and compared between groups by t test; Those who do not conform to the normal distribution are described by the median [M (Q(1), Q(3)) ] and analyzed by nonparametric test; The counting data were expressed in frequency and rate (% ), and the comparison between groups was tested. Results: Of the 41 cases, 33 were male and 8 were female. The age of the patient diagnosed with OI-COPD was (49.5±10.3) years old, and the minimum age was 30 years old; Among them, 8 patients had a definite long-term smoking history (more than 5 years) ; The exposure duration of occupational risk factors was (18.6±10.3) years, of which 3 patients had exposure duration of less than 5 years; The occupational risk factors leading to OI-COPD include acids and acid-forming compounds, bases, aldehydes, nitrogen oxides, chlorine and its compounds, etc. The exposure level of occupational risk factors is related to the degree of COPD airflow restriction (χ(2)=6.17, P <0.05). 18 patients with diagnosis age <50 years old were diagnosed as early-onset COPD. The incidence of respiratory symptoms in the early diagnosis COPD group was lower than that in the non-early diagnosis COPD group, and the FEV1% pred was significantly higher than that in the non-early diagnosis COPD group. The difference was statistically significant (P<0.01 ) . Conclusion: The exposure level of occupational risk factors may be the risk factor affecting the degree of COPD airflow restriction. With the increase of the exposure level of COPD patients, the proportion of respiratory symptoms will also increase accordingly.
Humans ; Male ; Female ; Adult ; Middle Aged ; Retrospective Studies ; China/epidemiology* ; Pulmonary Disease, Chronic Obstructive/diagnosis* ; Lung ; Risk Factors ; Occupational Diseases/diagnosis* ; Occupational Exposure/adverse effects*

Occupational disease hazards in plywood manufacturing mainly include wood dust, formaldehyde, phenol, ammonia, noise, terpene, microorganisms, etc. The exposure is complex with multiple factors accompanied or coexisted. In the production process, these factors are exceeded, and mass occupational disease hazard events occurred among workers. Exposure to wood dust, formaldehyde, terpene, etc., put workers at increased risk of cancer. This article provides a review of this issue in order to provide a scientific basis for the prevention and control of occupational disease hazards in plywood manufacturing.
Humans ; Wood/chemistry* ; Occupational Diseases/chemically induced* ; Formaldehyde/adverse effects* ; Terpenes ; Dust ; Occupational Exposure/adverse effects*

Objective: To analyze the concentrations of glyphosate and its metabolites in occupational exposed workers and their possible effects on human health, so as to provide a reference for improving the safe use of glyphosate and toxicity research. Methods: From April to December 2020, 247 workers directly exposed to glyphosate in 5 enterprises were selected as the contact group, and 237 workers who were not exposed to glyphosate and other pesticides in the same enterprise were selected as the control group. Questionnaire survey and occupational health examination were conducted on objects, and the concentrations of glyphosate and its metabolites in the air of workplaces and biological samples were detected. The correlation between the concentrations and the difference of health examination between the two groups were analyzed. Results: The urine glyphosate concentration (0.022-47.668 mg/L), the rate of exceeding the standard (60.32%, 149/247) and the urine aminomethyl phosphonic acid concentration (<0.010-1.624 mg/L) in the contact group were higher than those in the control group [urine glyphosate concentration (<0.020-4.482 mg/L), the rate of exceeding the standard (2.53%, 6/237) and the urine aminomethyl phosphonic acid concentration (<0.010-0.524 mg/L) ], respectively (P<0.001). The exceeding standard rate of glyphosate concentration in the workplace was 33.67% (33/98). The concentration of glyphosate in the workplace was positively correlated with the concentrations of glyphosate and aminomethylphosphonic acid in urine (r(s)=0.804, 0.238, P<0.001), and the concentration of glyphosate in urine was positively correlated with the concentration of aminomethylphosphonic acid in urine (r(s)=0.549, P<0.001). The alanine aminotransferase (ALT), white cell ratio, creatinine, uric acid, the abnormal rates of ALT and total protein (TP) in the contact group were higher than those in the control group, and TP was lower than that in the control group, the differences were statistically different (P<0.05). The abnormal rates of overall liver function, overall renal function, blood routine test, urine routine test, electrocardiogram, liver B ultrasound and blood lipid in the contact group were significantly higher than those in the control group (P<0.05) . Conclusion: The concentration of glyphosate in the workplace is related to the concentrations of glyphosate and aminomethyl phosphonic acid in the urine of workers, and exposure to glyphosate may have some harmful effects on human health.
Humans ; Occupational Exposure/adverse effects* ; Health Status

Cholinesterases/genetics* ; Dimethoate/analogs & derivatives* ; Humans ; Occupational Exposure/adverse effects* ; Polymorphism, Genetic ; Telomere