الفهرس | Only 14 pages are availabe for public view |
Abstract This work was conducted in a plastic factory (Menoufia governorate) to study respiratory and auditory disorders which may arise among workers in that industry. This study included an exposed group of plastic workers (180) who accepted participating in the study and a control (unexposed) group (60) from the worker’s relatives. Both groups were matched for age, sex, residence, marital status, income and educational level. The exposed group and controls were interviewed using a predesigned questionnaire about respiratory and auditory manifestations. Also, they were examined generally and locally for chest and ears. Spirometric measurements as well as Audiometry were carried out for both exposed group and controls aiming to assess pulmonary functions and hearing thresholds. Environmental studies were done by Tabbin Institute for Metallurgical Studies Central Laboratory for the Studies Industrial Pollution (TIMS/ CLISP) periodically via air sampling (using gas analyzer from the respiratory zone of the workers), assessment of noise at the level of workers ears (using sound level meter). Most commonly used plastics polymers are: a) thermoplastic resins as polyethylene, polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), styrene acrylonitrile (SAN), polycarbonate (PC), and acrylic, b) thermoset resins as polyurethane, epoxy, phenolics and polyester. Massive exposure to vinyl chloride may be responsible for irritation of the respiratory tract congestion; oedema and haemorrhages of the lungs have been observed in experimental animals.Impaired Summary and Conclusion 11 5 pulmonary function with decreased alveolocapillary permeability, as measured by single breath transfer for carbon monoxide (TLCO), was observed in workers exposed both to vinyl chloride and polyvinyl chloride dust. The incidence of lung cancers is increased in workers exposed to vinyl chloride. Occupational exposure to styrene is related to an increased risk of hearing loss. Combined exposures to noise and styrene seem to be more ototoxic than exposure to noise alone. The following results were obtained: - Polyvinyl chloride (PVC) and styrene levels were higher than that recommended by the Egyptian Ministry of Trade and Industry, Law 4 Decree 1095/2011 and NIOSH (2002). - Noise level was higher than the permissible exposure limits (PEL) by Egyptian environmental Law 4 for the year 1994 and NIOSH (1998) in some departments. - The prevalence of chest manifestations e.g. cough, dyspnea, wheezes and asthma were significantly higher among exposed group than controls among exposed smokers than exposed non-smokers. . - Regarding auditory manifestations, the exposed workers experienced a significantly higher prevalence of hearing impairment and tinnitus than controls. - Concerning the mean values of spirometric measurements the FEV1%, FEV1/FVC %, FEF25-75% and PEF% were significantly lower among exposed group than controls. Exposed smokers experienced significant lower mean values of the FVC%, FEV1%, FEV1/FVC % and FEF25-75% than exposed non-smokers. Summary and Conclusion 11 6 - Audiometric findings show different grades of decreased hearing threshold. Noise induced hearing loss is bilateral with V-dip depression in audiogram. This appears in some workers of exposed group not control one. - Within exposed group, the grinding department workers showed lower spirometric measurements than other departments and this may be attributed to the higher PVC and styrene level in this department. - Within exposed group, the grinding department workers showed higher prevalence of audiometric findings than other departments and this may be attributed to the higher noise level in this department. from above results, we can conclude that exposure to high level of PVC, styrene and noise in plastic industry are blamed to increase the frequency of chest manifestations, early spirometric changes and occupationally induced hearing loss; respectively. |