[Re-analysis of occupational hazards in foundry].
OBJECTIVE
To analyze systematically the characteristics of occupational hazards in the foundry, and provide precise data for epidemiology studies and control of occupational hazards in the foundry.


METHODS
Data of airborne dust, chemical occupational hazards and physical occupational agents in environment in the foundry from 1978 to 2008 were dynamically collected. Mean concentration and intensity (geometric mean) of occupational hazards were calculated by job in different years.


RESULTS
Main occupational hazards in the foundry were silica, metal fume, noise and heat stress. Silica existed in all of main jobs. The mean concentration of silica before 1986 was an extremely high level of 8.6 mg/m(3), and then remarkably dropped after 1986, with the level of 2.4 mg/m(3) from 1986 to 1989, 2.7 mg/m(3) from 1990 to 2002 and 2.7 mg/m(3) from 2003 to 2008. The trend of silica concentrations by job was consistent with that in general. Silica concentrations among jobs were significantly different, with highest level in melting (4.4 mg/m(3)), followed by cast shakeout and finishing (3.4 mg/m(3)), pouring (3.4 mg/m(3)), sand preparation (2.4 mg/m(3)), moulding (2.1 mg/m(3)) and core-making (1.7 mg/m(3)). Concentration of respirable dust in pouring was highest (2.76 mg/m(3)), followed by cast shakeout and finishing (1.14 mg/m(3)). Mean concentration of asbestos dust in melting was a relative high level of 2.0 mg/m(3). In core-making and sand preparation, there existed emission production of adhesive, with mean concentrations as followed, ammonia (5.84 mg/m(3)), formaldehyde (0.60 mg/m(3)), phenol (1.73 mg/m(3)) and phenol formaldehyde resin (1.3 mg/m(3)) also existed. Benzene and its homologues existed in cast shakeout and finishing, and the level of benzene, toluene, xylene was 0.2 mg/m(3), 0.1 mg/m(3) and 1.3 mg/m(3), respectively. In pouring and melting, there existed chemical occupational hazards, including benzo(a) pyrene, metal fume (lead, cadmium, manganese, nickel, chromium) and gas(hydrogen sulfide, phosphine, sulfur dioxide, carbon monoxide). Mean concentration of benzo(a) pyrene was a low level of 1.80 x 10(-4) microg/m(3). Physical occupational agents in the foundry were noise, heat stress and vibration. Intensity of heat stress was high in melting, pouring and cast shakeout and finishing, with the level of 30 degrees C, 29 degrees C and 26 degrees C, respectively. Noise was high in cast shakeout and finishing and core-making, with the level of 93.1 dB(A) and 89.5 dB(A), respectively. Vibration existed in core-making and cast shakeout and finishing. Compulsory postures included long standing, seating and bowing.


CONCLUSIONS
Occupational hazards in environment of the foundry are diversified and their concentrations exceed permissible exposure limits stipulated by the national occupational hygienic standards. High-concentrations of dust, metal fume, low-concentrations of variety of chemicals, high-intensity of noise and vibration, heat stress, and harmful compulsory posture, and so on all co-exist in the foundry. Control and protective measures should be strengthened.
Zhang
Min
M
Department of Epidemiology, School of Basic Medicine, Peking Union Medical College, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing 100005, China.
Qi
Cheng
C
Chen
Wei-Hong
WH
Lu
Yang
Y
Du
Xie-Yi
XY
Li
Wen-Jie
WJ
Meng
Chuan-San
CS
D004391:Dust / Q000032:analysis*; D015386:Hazardous Substances / Q000032:analysis*; D008669:Metallurgy; D016273:Occupational Exposure
D004391:Dust; D015386:Hazardous Substances