To investigate the
health impacts of crystalline
silica mixed
dust and other potential
occupational hazards on
workers in
ceramic factories, a
cohort study of 4851
workers registered in the
employment records in 3
ceramic factories in Jingdezhen city of
China between 1972 and 1974 was identified. The cohort
mortality was traced throughout 2003 with an accumulation of 128970.2
person-years, revealed 1542 deaths. Standardized
mortality ratios (SMRs) were calculated for the main
causes of death by using
Chinese national
mortality rates as reference. The
mortality from all causes in three
ceramic factories was 12.0 per thousand and the cumulative
mortality was 31.8%.
Malignant neoplasm,
cardiovascular diseases,
respiratory diseases,
infectious diseases were the first four illnesses that threaten
workers'
life, and they accounted for 73.2% of all deaths. The results of this study showed that the standardized
mortality ratio for all subjects was 1.02, which is very close to that expected on the basis of the
China national
mortality rates. Statistically significant
mortality excesses for respiratory
disease (SMR=1.36),
pneumoconiosis (SMR=37.34),
infectious disease (SMR=5.70) and
pulmonary tuberculosis (SMR=3.88) were observed. The
mortality of 2938
dust-exposed
workers was higher than that of 1913 non
dust-exposed
workers. Except for
pneumoconiosis, the
mortality from
lung cancer, non-malignant
respiratory diseases and
pulmonary tuberculosis in
dust-exposed
workers were significantly increased as compared with that in non-exposed
workers, and the
relative risks (RRs) were 1.86 (1.16-2.99), 2.50 (1.84-3.40), 1.81 (1.34-2.45). The exposure-response relationships between cumulative
dust exposure level and
mortality from all causes,
colorectal cancer,
lung cancer,
respiratory diseases, and
pulmonary tuberculosis were also identified. The findings indicated that
silica mixed
dust in
ceramic factories has harmful impact on the
workers'
health and
life span in
ceramic factory.