RESUMEN
Recent technological improvements in the printing industry may have altered noise exposures in printeries. Of the eight printery noise assessments published since 2000, none assessed the exposure of workers using computer-to-plate machines and only two used personal noise dosimetry. This method measures noise levels as the worker moves about and permits examination of the impulsiveness of noise levels. In this study, 104 workers wore personal noise dosimeters for one full shift. Computer-to-plate operators experienced noise exposures of 75 dB(A) on average and were rarely exposed to noise levels greater than 85 dB(A). Noise exposure in excess of 85 dB(A) was still common among offset printer operators. In fact, all workers operating web-fed offset machines spent more than half the shift experiencing noise levels greater than 85 dB(A). We found that the 5-min rolling SD of noise levels accurately reflected the impulsivity observed in the noise level profile.
Asunto(s)
Ruido en el Ambiente de Trabajo , Exposición Profesional , Humanos , IndustriasRESUMEN
This study reports on the occupational inhalation exposure to VOCs of workers in the Kuwaiti printing industry. Using the evacuated canister methodology, we targeted 72 VOCs in three printeries and compared the concentrations to previous reports and relevant occupational exposure levels (OELs). We found that recent efforts in the printing industry to reduce VOC usage had been successful, as concentrations of key hazardous VOCs were substantially lower than anticipated. On the other hand, nearly all target VOCs were found. Non-production areas were sampled along with the offset printing areas, another strength of this study, and revealed exposures to hazardous VOCs among administers and digital printer and CTP operators. Exposure to ototoxic VOCs amounted to 1-3% of the OEL, consisting mostly of ethylbenzene, which was likely in use in two of the study printeries. Exposure to carcinogenic or probably carcinogenic VOCs was 15-20% of the OEL at four locations across the three printeries, consisting mostly of vinyl chloride and benzyl chloride. Vinyl chloride VOC was partially sourced from outdoors, but was also likely used inside the study printeries. Interestingly, concentrations of vinyl chloride were similar in most sampling locations to that of CFC-114, a CFC banned by the Montreal Protocol and not commonly used as a refrigerant. This unexpected finding suggests further study is warranted to identify the use of these VOCs in printeries. Exposure to hazardous VOCs up to nearly 50% of the OEL, consisting largely of bromoform and vinyl chloride. Bromoform was found in all the study printeries, sourced partially from outdoor air. The higher concentrations found inside the study printeries likely resulted from the use of the desalinated water for washing. This finding raises of emissions from sources other than blanket washes, and inks, etc. adding to the total VOC load in printery indoor air. Implications: Results from this study indicate that efforts to reduce worker exposure to VOCs particularly dangerous to human health in recent years have been successful, but there is still much to be done to protect workers. Exposures to ototoxic and carcinogenic VOCs were identified, among both production and non-production workers. Unexpected findings included the apparent use in printing activities of the carcinogen vinyl chloride and CFC-114, banned under the Montreal Protocol. Observed lapses in safety procedures included failure to utilize ventilation systems and closing doors between work areas, indicating management and worker education should remain a priority.