OBJECTIVEDust sample mass gain is too smaller to satisfy the limit of detection (LOD) even in most cases during dust sampling at workplaces nowdays, especially for respirable fraction. Therefore, it is aimed to solve the problem by increasing sample load with high flow rate samplers.

METHODSIn A and B two shipyards respirable welding fume was sampled by high flow rate cyclone samplers of FSP-10 (10 L/min) for 2-2.5 hours and normal flow rate FSP-2 (2 L/min) for 3-4 hours with a stratigy of parallele sampling at the same workpalce, in order to compare their mass gain, coincidence rate with LOD, and airborn dust concentration.

RESULTSSample mass gain of 0.97±0.40 mg and 1.61±0.86 mg respectively in the two factories by FSP-10 was significantly higher than that of 0.29±0.12 mg and 0.51±0.27 mg by FSP-2 (t-test, P<0.05 in both cases) , increasing herewith the coincidence rate with LOD from 26.8% (when sampling with FSP-2, calculated together with samples of the two factories) to 89.7%. However there was no significant difference in dust concentrations by the two different samplers, 0.53±1.88 vs 0.73±1.61 mg/m(3) by FSP-2 and FSP-10 in the shipyard A and 1.14±1.78 vs 1.01±1.63 mg/m(3) in the factory B (t-test, P>0.05 in every case) . In addtion, sample loading by FSP-2 was found to be correlated to sampling time (R(2)=0.7906, y=0.002 6x) , therefore, it has to sample for ≥192.3 min to meet the LOD (0.5 mg) in case of normal flow rate.

CONCLUSIONBy using of high flow rate cyclone FSP-10 the problem of LOD could be solved, along with increased sample mass and similar respirable dust concentration by the two samplers. Some techincal improvements of FSP-10 and increasing of LOD coincidence rate by other methods was also disscussed.

Air Pollutants, Occupational ; analysis ; Construction Industry ; Dust ; analysis ; Environmental Monitoring ; instrumentation ; Occupational Exposure ; Ships ; Workplace

Objective To study the applicability of two different occupational health risk assessment methods for noise positions in a beer manufacturing enterprise. Methods An occupational health investigation along with the detection of occupational hazard factors were carried out in the workplace of a beer manufacturing enterprise in Wuhan. Workers with 8-hour working day equivalent sound level (LEX,8 h) ≥ 80 dB (A) were selected as research subjects. The ^“Guidelines for Noise Occupational Disease Risk Management^” method and occupational hazard risk index method were used to assess the risk of noise jobs in the beer manufacturing company. The assessment results of the two methods were compared. Results The noise exposure level of the enterprise was between 81.2 and 91.2dB(A). The guideline method predicted that the risk of high-frequency hearing loss and noise deafness for wine bottling workers and labelers on the bottling production line was high after 35 years exposure to noise. Washing，inspection and boxing on the bottling production line and bottling up on the canning production line were at medium risk, and others were at low risk. The evaluation results of the occupational hazard risk index method showed that the bottlers, bottling workers, wine inspectors, labelers and boxers on the bottling production line were at medium risk, and other positions were at low risk. Conclusion The occupational hazard risk index method is more comprehensive to consider all the factors of health risk, and the evaluation results are close to the ^“Guidelines for Noise Occupational Disease Risk Management^” method. The guideline method can quantitatively predict the risk of high-frequency hearing loss and noise deafness, and the risk of hearing loss increases with the extension of years of noise exposure.

Objective To analyze the detection level and distribution characteristics of occupational contraindications in pre-employment occupational health examination, and to provide a reference for relevant management departments to strengthen the control of personnel exposed to occupational hazards. Methods The data of pre-employment occupational health examination of 2 626 workers in a vehicle manufacturing enterprise from September 2018 to December 2020 were collected. The detection rate of occupational contraindications was calculated according to the judgement standard, and the distribution of occupational contraindications in different gender, length of service and age was analyzed. Results The detection rate of occupational contraindications was 13.71%, and there was no significant difference between the genders. The detection rate in the 40-45 years old group was the highest (31.75%), and the difference among the different age groups was statistically significant (χ²=30.16, P<0.01). Among the workers with different length of occupational employment, the detection rate was the highest in the group with 20-25 working years (30.65%), and the difference was statistically significant (χ²=30.20, P<0.01). Conclusion Relevant departments should strengthen the occupational health supervision and management of vehicle manufacturing enterprises and urge enterprises to pay attention to the pre-job occupational health examination as well as the health of workers.

Objective To explore the results, feasibility and existing problems of semi-quantitative and quantitative risk assessment models in the assessment of chemical hazard exposure in optical fiber manufacturing enterprises.  Methods The chemical hazard factors of an optical fiber enterprise in Wuhan were investigated, detected and evaluated, and the semi-quantitative and quantitative risk assessment models of occupational health of chemical hazard factors in the workplace were used for risk assessment. Results In the semi-quantitative risk assessment model, the consistency between the contact index method and the comprehensive index method was good (Kappa=0.820, P<0.01), and the result was grade 2-3.  The evaluation results of the contact ratio method were significantly correlated with those of E/OEL (r²=0.539，P<0.05), and the results were grade 1, 2, 3 and 5.  The non-carcinogenic risk hazard quotient of the quantitative risk assessment model was not consistent with the three semi-quantitative methods (Kappa=0), and the results were grade 1, 2, 3, 4 and 5.   Conclusion The semi-quantitative risk assessment model is more suitable for the risk assessment of the optical fiber industry than the quantitative risk assessment model.