ABSTRACT
<p><b>OBJECTIVE</b>To investigate the incidence of malignant tumors among fluoride-exposed workers in aluminum industry.</p><p><b>METHODS</b>Sampling points were set in the working positions at different radii around an workshop for treating the waste gas from aluminum electrolysis, and the concentrations of fluoride ions, aluminum, and benzo[a]pyrene (B[a]P) in air were measured by electrode method, atomic absorption spectrophotometry, and high performance liquid chromatography, respectively. The incidence of tumors among the workers in the aluminum plant from 1995 to 2009 was investigated by questionnaires and medical records and then statistically analyzed.</p><p><b>RESULTS</b>There was a negative correlation between the concentrations of fluoride and aluminum and the radius around the fluoride source at each sampling point. B[a]P was not detected at each sampling point. The crude incidence rate of tumors among factory workers was 117.95/100 000 (standardized rate = 58.81/100 000); the standardized incidence rate of tumors was higher in female workers than in male workers (male-to-female ratio = 1:2.64). The peak age of onset of tumors was 40 ∼ 49 years. The most and second most common tumors were liver cancer and lung cancer in male workers and breast cancer and lung cancer in female workers. Compared with the unexposed population in the city where the aluminum plant was located, the female fluoride-exposed workers had an increased tumor incidence, 2.14 times that of the city's average level, and the fluoride-exposed workers had a younger age of onset of tumors and approximately the same types of tumors.</p><p><b>CONCLUSION</b>Fluoride exposure may lead to an increasing trend in tumor incidence among female workers in aluminum industry.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Aluminum , Fluorides , Metallurgy , Neoplasms , Epidemiology , Occupational ExposureABSTRACT
<p><b>OBJECTIVE</b>To study the effects of low level manganese (Mn) exposure on the serum neuroendocrine hormones levels of the welders.</p><p><b>METHODS</b>The exposure group consisted of 41 male welders, 40 male workers without exposing to harmful agents served as controls. The serum contents of prolactin (PRL), luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (TST) and thyroid stimulating hormone (TSH) of 81 subjects were detected by chemiluminescence immunoassay.</p><p><b>RESULTS</b>The geometric mean value of airborne Mn concentrations was 0.03 mg/m(3) (0.003 - 0.519 mg/m(3)) in the welding circumstances. The levels of Mn in red blood cells (RBCs) and urinary Mn of the exposure group were significantly higher than those of control group (P < 0.01). The contents of serum LH and TSH of the exposure group were 2.89 ± 0.69 mIU/ml and 1.45 ± 0.56 uIU/ml, which were significantly lower than those (3.82 ± 1.61 mIU/ml and 2.19 ± 1.28 µIU/ml) of control group (P < 0.01). The serum contents of LH, FSH and TSH of the group exposed to Mn for < 5 years were significantly lower than those of the control group, The serum TST level of the group exposed to Mn for < 5 years was significantly higher than those of the control group and group exposed to Mn for 5 ∼ years, the serum FSH level of the group exposed to Mn for < 5 years was significantly lower than that of the group exposed to Mn for 10 years (P < 0.05 or P < 0.01). The serum contents of LH and TSH of the group exposed to Mn for 5 ∼ years were significantly lower than those of the control group (P < 0.05 or P < 0.01). The serum contents of PRL, LH and TSH of the group exposed to Mn for 10 years were significantly lower than those of the control group (P < 0.05). There was negative correlation between blood (RBC) Mn and urinary Mn (r = -0.310, P < 0.05), also there was negative correlation between serum PRL and serum TST (r = -0.409, P < 0.01), the positive correlation between serum LH and serum FSH was observed (r = 0.361, P < 0.05).</p><p><b>CONCLUSION</b>The results of present study showed that the long exposure to low level of Mn may decrease the levels of serum PRL, LH and TSH in workers occupationally exposed to Mn, which can influence the metabolism of neuroendocrine hormones to certain extent.</p>