OBJECTIVETo characterize the distribution of work-related musculoskeletal disorders (WRMD) among the occupational population.

METHODSA total of 1686 people of various occupations were recruited with random cluster sampling. Standardized Nordic questionnaires for the analysis of musculoskeletal systems were used to evaluate WRMD at the neck, shoulder, or lower back in the past one year. The annual prevalence of WRMD was determined. Difference analysis was performed with t-test, ANOVA, or chi-square test. The relationship between personal characteristics and WRMD was analyzed by unconditional logistic regression.

RESULTS(1) WRMD were most frequently observed at the neck, followed by the lower back, and was least observed at the shoulder (P < 0.05). The prevalence of WRMD among mental workers was significantly higher than those among physical workers and mental-physical workers (P < 0.01). The prevalence of WRMD among female workers was significantly higher than that among male workers (P < 0.05). (2) In general, the prevalence of WRMD significantly rose with the increases in age (<30, 30∼, 40∼, and ≥ 50 years) or working years (<10, 10∼, and ≥ 20 years) (P < 0.05). (3) In the face of sickness or injury, physical workers and mental workers showed a relatively high absence rate but a relatively low medical visiting rate (13.05%). (4) Unconditional logistic regression analysis showed that mental work, gender, and working year were the main influential factors for WRMD among workers.

CONCLUSIONWorkers of different types of occupation, genders, ages, and working years have different risks of WRMD at the neck, shoulder, and lower back.

Adult ; Female ; Humans ; Logistic Models ; Male ; Middle Aged ; Musculoskeletal Diseases ; epidemiology ; Occupational Diseases ; epidemiology

Adolescent ; Adult ; China ; epidemiology ; Female ; Humans ; Male ; Middle Aged ; Occupational Diseases ; epidemiology ; Poisoning ; epidemiology ; Young Adult

OBJECTIVETo investigate the noise hazards in open quarries and to provide a basis for further control of noise hazards.

METHODSAn investigation was performed during 2010 to 2011 among all open quarries in Deqing County of Zhejiang Province, China. The investigation included basic information of the quarries, the occupational health situation and noise intensity at the workplace, and the hearing loss of workers exposed to noise in quarry enterprises. The hearing test results were evaluated based on the Diagnostic criteria of occupational noise-induced hearing loss (GBZ 49-2007).

RESULTSA total of 25 enterprises with open quarries were investigated, of which only 30.4% (17/56) workplaces met the national standard. The median noise level was 92.5 dB (A). Fifty-four (10.6%) out of 508 workers in the 25 enterprises were diagnosed with binaural hearing loss in the initial physical examination, with 18.3% (93/508) under surveillance. The rate of normal hearing among crushing workers, mechanists, drilling workers, and blasting workers ranged between 27.6% and 41.4%, which was significantly lower than that among workers exposed to slight noise hazards (80.0%) or other workers (63.7%) (P < 0.05). With increasing working years, the binaural hearing loss of crushing workers became serious.

CONCLUSIONSerious occupational noise hazards existed in most jobs in open quarries, with crushing workers, mechanists, drilling workers, and blasting workers most seriously jeopardized. Among crushing workers, those working in the first-line or unprotected second?line positions suffered more than the others. Further measures should be taken by the supervision department and the enterprises to control the noise hazards in open quarries.

Hearing ; Hearing Loss, Noise-Induced ; Humans ; Mining ; Noise, Occupational ; Occupational Exposure

Adult ; Female ; Humans ; Male ; Medical Staff, Hospital ; Middle Aged ; Occupational Diseases ; epidemiology ; Urticaria ; epidemiology ; Young Adult

OBJECTIVETo find a sensitive index of early injury of the nervous system in lead-exposed workers and to provide a scientific basis for establishing an efficient occupational health surveillance route.

METHODSA total of 317 lead-exposed workers (blood lead levels: 26.90∼ 912.80 µg/L, determined with the atomic absorption spectrum) were divided into four groups according to the normal blood lead level (201 µg/L), acceptable upper limit of blood lead (400 µg/L), and diagnostic value (600 µg/L). The motor nerve conduction function was examined and analyzed by one-way ANOVA.

RESULTSThe distal latency and amplitude of the median nerve were significantly different between groups. The median distal latency of the highest blood lead group (>600 µg/L) was 3.63 ms, which was significantly longer than the average level (3.30 ms), and the median nerve amplitude of the highest blood lead group was 5.63 µV, significantly lower than the average level (7.27 µV). No significant difference was found between different groups in motor conduction velocity. Significant difference was found in ulnar nerve amplitude between groups. The ulnar nerve amplitude of the highest blood lead group was 4.31 µV, significantly lower than the average level (4.87 µV). No significant differences were observed in other parameters between groups.

CONCLUSIONThe distal latency and amplitude of the median nerve can be used as a sensitive index for the diagnosis of early subclinical motor nerve injury in lead?exposed workers.

Adult ; Humans ; Lead ; blood ; Lead Poisoning ; blood ; physiopathology ; Neural Conduction ; drug effects ; Occupational Exposure

Humans ; Occupational Exposure ; Railroads

Adult ; Air Pollutants, Occupational ; adverse effects ; Health Status ; Humans ; Male ; Middle Aged ; Occupational Exposure ; adverse effects ; Toluene 2,4-Diisocyanate ; adverse effects ; Young Adult

OBJECTIVETo study the excision repair capacity of human 8-oxoguanine DNA N-glycosylase 1 (hOGG1) for 8-OH-dG and the oxidative DNA damage among workers exposed to nickel in stainless steel production environment.

METHODSA total of 231 workers exposed to nickel in a stainless steel production enterprise were recruited as nickel exposure group, and another 75 water pump workers in that enterprise were recruited as control group. The workplace occupational hazard factors were determined. Double-antigen sandwich ELISA was used to determine urinary 8-OH-dG level; RT-PCR was used to determine hOGG1 mRNA level. Pearson correlation was used to analyze the correlation between urinary 8-OH-dG level and hOGG1 mRNA level.

RESULTSLevel of 8-OH-dG was compared between different types of nickel-exposed workers and control workers; rolling mill workers showed no significant difference from the control group (P > 0.05), while steel making workers and steel slag disposing workers showed significant differences from the control group (P < 0.05). Level of 8-OH-dG was also compared between nickel-exposed workers with different working years and control workers; nickel-exposed workers with 0∼5 and 6∼10 working years showed no significant differences from the control group (P > 0.05), while other exposed workers showed significant differences from the control group (P < 0.05). Different types of nickel-exposed workers all showed significant differences from the control group in hOGG1 mRNA level (P < 0.05). Nickel-exposed workers with 0∼5 working years showed no significant difference from the control group in hOGG1 mRNA level (P > 0.05), while other exposed workers showed significant differences from the control group (P < 0.05). Pearson correlation analysis showed that urinary 8-OH-dG level was positively correlated with hOGG1 mRNA level (r = 0.993) in different types of nickel-exposed workers, and the correlation was significant at α = 0.01 (P < 0.05); urinary 8-OH-dG level also showed a positive correlation with hOGG1 mRNA level in nickel-exposed workers with different working years (r = 0.968), and the correlation was significant at α = 0.01 (P < 0.05).

CONCLUSIONExposure to nickel increases oxidative DNA damage among steel workers, and hOGG1 shows active excision repair capacity for 8-OH-dG.

Adult ; DNA Damage ; DNA Glycosylases ; metabolism ; DNA Repair ; Humans ; Male ; Metallurgy ; Middle Aged ; Nickel ; adverse effects ; Occupational Exposure ; adverse effects ; Stainless Steel ; Young Adult

OBJECTIVETo investigate the relationship between the genetic polymorphisms of matrix metalloproteinase-2 (MMP-2) (-735) and matrix metalloproteinase-3 (MMP-3) (-1171) and the susceptibility to silicosis.

METHODSA case-control study was conducted in 113 patients diagnosed with stage I silicosis (case group) and 115 dust-exposed workers without silicosis (control group); the two groups had the same sex, ethnic group, and type of dust and similar age and cumulative exposure time. Polymerase chain reaction-restriction fragment length polymorphism was used to determine the genotypes of MMP-2 (-735) and MMP-3 (-1171).

RESULTSNo significant difference was observed in age, cumulative exposure time, or smoking rate between cases and controls (P > 0.05). The frequencies of genotypes C/C, C/T, and T/T at MMP-2 C-735T in the case group were 57.5% (65/113), 31.0% (35/113), and 11.5% (13/113), respectively, which were significantly different from those of the control group (69.6% (80/115), 26.9% (31/115), and 3.5% (4/115)), χ² = 6.542, P < 0.05). The frequencies of T allele in cases and controls were 27.0% and 17.0%, respectively, which were significantly different from each other χ² = 6.704, P < 0.05). Carriage of T allele at MMP-2 C-735T increased the risk of silicosis (OR = 1.811, 95% CI: 1.151-2.847). The frequencies of genotypes 6A/6A, 5A/6A, and 5A/5A at MMP-3 A-1171A were 67.2% (76/113), 24.8% (28/113), and 8.0% (9/113), respectively, in the case group, versus 59.1% (68/115), 37.4% (43/115), and 3.5% (4/115) in the control group (χ² = 5.519, P > 0.05).

CONCLUSIONGenetic polymorphism at MMP-2 C-735T is significantly associated with the development of silicosis. Carriage of T allele increases the risk of silicosis among workers exposed to dust. No significant association was found between MMP-3 A-1171A polymorphism and silicosis in this study.

Adult ; Aged ; Aged, 80 and over ; Case-Control Studies ; Genetic Predisposition to Disease ; Genotype ; Humans ; Matrix Metalloproteinase 2 ; genetics ; Matrix Metalloproteinase 3 ; genetics ; Middle Aged ; Polymorphism, Genetic ; Silicosis ; genetics

OBJECTIVETo investigate the association between single nucleotide polymorphisms (SNPs) in glutathione peroxidase 1 (GPX-1) gene, rs3448, rs1050450, rs1800668, and rs1987628, and the susceptibility to noise-induced hearing loss (NIHL) among Chinese Han population.

METHODSA case-control study was conducted to investigate the threshold shift of the left ear at 3000 Hz among the workers of Chinese Han population who were exposed to the same level of sound pressure. Two hundred and one (10%) of the subjects with the highest level of threshold shift were recruited in susceptible group, while 202 of (10%) of the subjects with the lowest level of threshold shift were recruited in tolerant group. Targeted occupational health survey and questionnaire survey were performed among these people. For each individual, genome DNA was extracted from 5 ml of fasting peripheral venous blood. Four SNPs (GPX-1 rs3448, rs1050450, rs1800668, and rs1987628) were genotyped by the TaqMan SNP genotyping kit. The main effects of SNPs and the association between NIHL susceptibility and SNPs were analyzed by logistic regression.

RESULTSThe C allele of rs1987628 was a risk factor for NIHL, with an odds ratio (OR) of 2.531 (95%CI: 1.878-3.411) as compared with the T allele. The CC genotype of rs1987628 was more associated with NIHL than the TT genotype (OR = 3.500, 95% CI: 1.984-6.174; adjusted OR = 3.544, 95% CI: 1.974 ∼ 6.364).

CONCLUSIONAmong Chinese Han population, GPX-1 SNP rs1987628 may be associated with the susceptibility to NIHL.

Adult ; Case-Control Studies ; Female ; Genetic Predisposition to Disease ; Glutathione Peroxidase ; genetics ; Hearing Loss, Noise-Induced ; genetics ; Humans ; Male ; Polymorphism, Single Nucleotide ; Young Adult