Noise exposure and its impact on health in an auto parts manufacturing enterprise / 中华劳动卫生职业病杂志

Objective: To learn about the noise exposure and health status of workers and analyze factors that may affect the health outcomes of workers in an auto manufacturing enterprise in Tianjin City. Methods: In September 2020, occupational hygiene survey, noise exposure level detection and occupational health examination data collection were carried out in an auto parts manufacturing enterprise. Chi square test and unconditional logistic regression analysis were used to analyze the health effects of noise exposure and hearing loss of 361 noise exposure workers. Results: The rates of over-standard noise exposure, hearing loss and hypertension were 69.39% (34/49) , 33.24% (120/361) and 11.36% (41/361) , respectively. There were upward trends on age and noise-working years for hearing loss and hypertension rates (χ(2)=-5.95, -6.16, -2.81, -2.74, P<0.05) . Unconditional logistic regression analysis showed that age>35 years old, noise exposure length of service >10 years and noise L(EX, 8 h)>85 dB (A) were risk factors for hearing loss (OR=3.57, 95%CI: 1.09, 11.75; OR=4.05, 95%CI: 1.97, 8.25; OR=1.75, 95%CI: 1.00, 3.05; P=0.036, 0.001, 0.047) . Conclusion: This company has a high rate of job noise exceeding the standard, and noise-exposed workers have more serious hearing loss. Age, noise exposure and high noise exposure are risk factors for hearing loss.

Characterization, Biocompatibility, and Optimization of Electrospun SF/PCL/CS Composite Nanofibers.

In this study, composite nanofibers (SF/PCL/CS) for the application of dressings were prepared with silk fibroin (SF), polycaprolactone (PCL), and chitosan (CS) by electrospinning techniques, and the effect of the fiber diameter was investigated using the three-stage Taguchi experimental design method (L9). Nanofibrous scaffolds were characterized by the combined techniques of scanning electron microscopy (SEM) and transmission electron microscopy (TEM), a cytotoxicity test, proliferation tests, the antimicrobial activity, and the equilibrium water content. A signal-to-noise ratio (S/N) analysis indicated that the contribution followed the order of SF to PCL > flow rate > applied voltage > CS addition, possibly owing to the viscosity and formation of the beaded fiber. The optimum combination for obtaining the smallest fiber diameter (170 nm) with a smooth and uniform distribution was determined to be a ratio of SF to PCL of 1:2, a flow rate of 0.3 mL/hr, and an applied voltage of 25 kV at a needle tip-to-collector distance of 15 cm (position). The viability of these mouse fibroblast L929 cell cultures exceeded 50% within 24 hours, therefore SF/PCL/CS could be considered non-toxic according to the standards. The results proposed that the hydrophilic structure of SF/PCL/CS not only revealed a highly interconnected porous construction but also that it could help cells promote the exchange of nutrients and oxygen. The SF/PCL/CS scaffold showed a high interconnectivity between pores and porosity and water uptake abilities able to provide good conditions for cell infiltration and proliferation. The results from this study suggested that SF/PCL/CS could be suitable for skin tissue engineering.