Advances on associations of exposure to air pollutants during pregnancy with congenital heart disease in offspring / 环境与职业医学

Congenital heart disease (CHD) is the most common birth defect and one of the major causes of neonatal death, with an average prevalence of 9.4‰ worldwide. We reviewed recent epidemiological studies and found that exposure to air pollutants is associated with increased CHD risks, but the associations are inconsistent between exposure to air pollutants and different subtypes of CHD due to developmental and etiological heterogeneity among different subtypes of CHD. It has been reported that air pollutants are associated with increased risks of ventricular septal defect, patent ductus arteriosus, pulmonary stenosis, tetralogy of Fallot, and transposition of the great arteries. However, associations between maternal exposure to air pollutants and atrial septal defect (ASD) are contradictory, with significantly positive associations of inhalable particulate matter and nitrogen dioxide exposure, negative associations of fine particulate matter and carbon monoxide, and mixed associations of sulfur dioxide. Adverse effects of air pollutant on cardiac development cover a wide time window beyond 3-8 weeks during gestation; particulate matter and nitrogen oxide are more likely to affect fetal heart in early pregnancy, while the association strength of carbon monoxide shows a trough in early pregnancy, and sulfur dioxide and ozone affect cardiac health throughout pregnancy. In addition, we discussed the limitations of previous studies on the associations between maternal air pollutant exposure and CHD, and highlighted the application of precise assessment on exposure to air pollutants, the performance of prospective cohort studies and longitudinal studies, and the necessity of studies on CHD subtypes, in order to provide scientific evidence to control exposure to environmental pollutants and CHD occurrence.

Noise-induced hearing loss associated with non-Gaussian noise in manufacturing industry of China: A systematic review and meta-analysis / 环境与职业医学

Background Non-Gaussian noise has become the dominant noise type in industry. However, the epidemiological characteristics of non-Gaussian noise exposure and associated noise-induced hearing loss (NIHL) are still unclear. Objective To summarize the epidemiological characteristics of NIHL associated with non-Gaussian noise in manufacturing industry in China and provide a basis for the early prevention and control of occupational hearing loss. Methods Chinese and English literature on hearing loss associated with non-Gaussian noise in China were retrieved. The overall prevalence was calculated based on the prevalence data provided by each included study. A meta-analysis of studies with Gaussian noise as a control group was also performed and the overall weighted odds ratio (OR) was calculated to compare the effects of non-Gaussian noise and Gaussian noise on hearing loss. Publication bias was evaluated by funnel plot and Egger regression, and a sensitivity analysis was performed by eliminating references in turn. Results A total of 37 cross-sectional studies involving 25 055 Chinese manufacturing workers exposed to non-Gaussian noise were included, 92.5% of whom were male. These workers aged (32.7±9.6) years were exposed to non-Gaussian noise at (87.0±4.2) dB(A) for (6.8±4.9) years. The mean cumulative noise exposure (CNE) was (95.9±8.0) dB(A)·year. The prevalence rate of high-frequency NIHL (HFNIHL) and speech-frequency NIHL (SFNIHL) were 29.0% and 14.2%, respectively. The results of the meta-analysis treating 19 cross-sectional studies with Gaussian noise as a control group showed that there were no significant differences in age, exposure duration, and equivalent continuous A-weighted sound pressure level (LAeq), and CNE between the non-Gaussian noise group and the Gaussian noise group. The overall weighted OR of HFNIHL was 1.87 (95%CI: 1.46−2.41), which was statistically significant. The funnel plot showed good symmetry and the result of Egger regression was t=−0.11, P=0.910 (>0.05), suggesting a low risk of publication bias in this meta-analysis. The sensitivity analysis showed no significant changes of results after eliminating references in turn, indicating that the results were robust. Conclusion Chinese manufacturing workers, mainly young adult males, are exposed to non-Gaussian noise at high levels for a long time and have a high prevalence of NIHL. Compared to workers exposed to Gaussian noise, those exposed to non-Gaussian noise suffer from more serious hearing loss.

Correctly Handle Mutual Relationship of Community and Higher-level Hospitals in order to Make the Most of Community Health Services / 中国医学伦理学

The reasonable disposition of health resources and convenient access to medical service for citizens can be realized by correctly handling the workload inequality between Community and Higher-level Hospitals,expanding the development of community hospitals,and making the most of community health services.By conducting research on the community health services in Wenzhou,we believe the creation of first medical treatment in community hospitals and the "two-way referral system" between superior and subordinate hospitals to be a "win-win" pattern to reduce the burden from patients,improve the operational efficiency of higher-level hospitals and also make benefits for community hospitals.