Investigation On Occupational Health Surveillance Of Workers Exposed To Carbon Disulfide In A Rayon Fiber Enterprise Duringthe Employment Period

ObjectivesThis project studies the implementation of occupational health surveillance of carbon disulfide (CS2) exposed workers in rayon fiber companies. It analyzes current practical issues and suggests improvements for decision-makingbased on scientific analysis.MethodsThe cross-sectional study and topic interview wereconducted on a field survey on rayon fiber enterprise. The study surveyed the status of workplace exposure, the occupational health surveillance of CS2exposed workers, and the economic cost estimated of the various physical examination indexes.Data was collected with the Epidata3.1software, and analyzed statistically with SPSS.18.Results1. The data of CS2concentration measures in workplace were collected from172sampling stations in4viscose fiber factories during2009-2010. In total2592data points were acquired.71%of the sampling stations in spinning workshops recorded CS2concentrations that exceed the national occupational exposure limit (OEL). The geometric mean of the time-weighted average concentration (TWA) of spinner was10.23mg/m3, which is also above the national OEL.2. In2010, the occupational health physical examination of CS2exposed workers showed that incidences of abnormal neurological signs, retinopathy and glycemia were6.0%,0.6%and1.9%respectively, and the rates increasedwith increasing work age, statistically significant differences among the different work age groups (P<0.05).The abnormal rates in the low exposure group (≤2.5mg/m3), median exposure group(2.5～5mg/m3) and high exposure group (>5mg/m3) were11.0%,6.9%and7.9%respectively. However, there were no statistical differences among groups (P>0.05).3. Three abnormal neurological signs (eyelid, tongue and hand tremors, ETH tremors) were strongly noticeable. The positiverate of ETH tremors was2.4%and increased with work age, with statistically significant differences among the work age groups (P<0.05).4. From2004to2010, the average participation rate of the occupational health examination of CS2exposed workers was only25.3%.The highest participation ratewas38.2%, which is still relatively low.5. The main problems with occupational health surveillance of rayon fiber enterprise were related with the inexperience with occupational health practices, including theinadequacy of management rules and regulations, the shortage of the health surveillance funds, lack of professional knowledge of management personnel, insufficient standardization and irregular archives management, etc.Conclusions1. The key issue of CS2occupational hazard in the rayon fiber enterprise is located in the spinning workshop where workers face a higher exposureenvirement. Enterprise should give the spinning workshop and its workers high priority in prevention and occupational health surveillance2. The results of physical examination of CS2exposed workers showed that the work age is an important factorinfluencing workers health.In the occupational health examination, enterprise should give more attention to workers with long work age, especially for workers that have been active more than20years.3. Positive rates of ETH tremors, both in the CS2exposed workers and CS2poisoning workers were high, and the rates increased with work age. Whether the ETH tremors caused by early nerve damage can be used as an early and more sensitive detection instrument of occupational health examination than other neurological signs, which still requires further research.4. Abnormal rates of retinopathy and glycemia in the exposed workers were0.52%and1.93%respectively, which is lower than in the general population. Whether blood glucose level or fundus tests should remain part of the physical examination index of CS2exposed workers in the occupational health examination, needs to be studied more.5. The average participation rate of the occupational health examination of CS2exposed workers in Rayon fiber enterprise was25.3%, and the highest rate was only38.2%. The main arguments for enterprise to have low participation rates werethe shortage of legal consciousness, insufficient attention, and the monetary cost of the current medical examinations, which was felt to be a heavy burden.In response to the high costs of physical examination, companies slashed the number of workersto participate examination, which indirectly caused the low examination rates.6. Enterprise does not have suitable rules and regulations for occupational health surveillance management in workplace. They lack specific health surveillance funding, professional knowledge of management personnel, and occupational health surveillance archives management are non-standardized and irregularly kept. Thesewere the main factors to influence the work effect of occupational health surveillances.