Occupational disease hazards in plywood manufacturing mainly include wood dust, formaldehyde, phenol, ammonia, noise, terpene, microorganisms, etc. The exposure is complex with multiple factors accompanied or coexisted. In the production process, these factors are exceeded, and mass occupational disease hazard events occurred among workers. Exposure to wood dust, formaldehyde, terpene, etc., put workers at increased risk of cancer. This article provides a review of this issue in order to provide a scientific basis for the prevention and control of occupational disease hazards in plywood manufacturing.
Humans ; Wood/chemistry* ; Occupational Diseases/chemically induced* ; Formaldehyde/adverse effects* ; Terpenes ; Dust ; Occupational Exposure/adverse effects*

The present review summarizes the results of several follow-up studies assessing an asbestos product manufacturing plant in Chongqing, China, and discusses three controversial issues related to the carcinogenicity of asbestos. The first issue is the amphibole hypothesis, which asserts that the carcinogenicity of asbestos is limited to amphiboles, such as crocidolite, but not serpentines, such as chrysotile. However, considering the possible multiple component of asbestos carcinogenicity in the presence of tobacco smoke or other carcinogens, chrysotile cannot be regarded as non-carcinogenic. Additionally, in a practical sense, it is not possible to assume "pure" chrysotile due to its ubiquitous contamination with tremolite, which is a type of amphibole. Thus, as the International Agency for Research on Cancer (IARC) assessed, all forms of asbestos including chrysotile should be regarded carcinogenic to humans (Group 1). The second issue is the chrysotile/tremolite paradox, which is a phenomenon involving predominant levels of tremolite in the lung tissues of individuals who worked in locations with negligible levels of tremolite due to the exclusive use of chrysotile. Four possible mechanisms to explain this paradox have been proposed but this phenomenon does not support the claim that amphibole is inert. The final issue discussed is the textile mystery, i.e., the higher incidence of cancer in asbestos textile plants compared to asbestos mines where the same asbestos was produced and the exposure levels were comparable. This phenomenon was first reported in North America followed by UK and then in the present observations from China. Previously, levels of fiber exposure were calculated using a universal converting coefficient to estimate the mass concentration versus fiber concentration. However, parallel measurements of fiber and mass concentrations in the workplace and exposed air indicated that there are wide variations in the fiber/mass ratio, which unjustifies the universal conversion. It is possible that contamination by airborne non-fibrous particles in mines with mass fiber conversion led to the overestimation of fiber concentrations and resulted in the textile mystery. Although the use and manufacturing of asbestos has been banned in Japan, more than 10 million tons of asbestos had been imported and the majority remains in existing buildings. Thus, efforts to control asbestos exposure should be continued.
Asbestos ; classification ; toxicity ; Asbestos, Amphibole ; toxicity ; Asbestos, Serpentine ; toxicity ; Carcinogens ; China ; Follow-Up Studies ; Humans ; Lung Neoplasms ; chemically induced ; epidemiology ; Manufacturing and Industrial Facilities ; statistics & numerical data ; Mining ; statistics & numerical data ; Occupational Diseases ; epidemiology ; Occupational Exposure ; adverse effects ; Textiles ; Tobacco Smoking ; epidemiology

BACKGROUND: Plastic resins are complex chemicals that contain toluene diisocyanate (TDI) and/or trimellitic anhydride (TMA), which cause occupational allergies (OA), including respiratory allergies. Serum IgGs against TDI and TMA have been suggested as potential markers of the exposure status and as exploring cause of OA. Although TDI-specific IgG has been examined for suspected OA, TMA-specific IgG is not commonly evaluated in a urethane foam factory. This study therefore investigated both TDI- and TMA-specific IgGs in suspected OA patients and to evaluate the usefulness of the measurement of multiple chemical-specific IgG measurement for practical monitoring. METHODS: Blood samples were collected from two male workers who developed respiratory allergies supposedly caused by occupational exposure to TDI and/or TMA for the presence of TDI- and TMA-specific IgGs. In addition, blood samples from 75 male workers from a urethane foam factory, along with 87 male control subjects, were collected in 2014 and tested for the same IgGs in 2014. The presence and levels of TDI- and TMA-specific serum IgGs were measured using dot blot assays. RESULTS: We found that controls had mean concentrations of TDI- and TMA-specific IgGs of 0.98 and 2.10 μg/mL, respectively. In the two workers with respiratory allergies, the TDI-specific IgG concentrations were 15.6 and 9.51 μg/mL, and TMA-specific IgG concentrations were 4.56 and 14.4 μg/mL, which are clearly higher than those in controls. Mean concentrations of TDI- and TMA-specific IgGs in the factory workers were 1.89 and 2.41 μg/mL, respectively, and are significantly higher than those of the controls (P < 0.001 and P < 0.026 for TDI- and TMA-specific IgGs, respectively). CONCLUSION The workers suspected of OA showed an evidently high level of TDI- and TMA-specific IgG, and these levels in workers at the urethane foam factory were also significantly higher than those in controls. In conclusion, the measurement of TDI- and TMA-specific IgG among workers using plastic resins is helpful to monitor their exposure status.
Adult ; Air Pollutants, Occupational ; adverse effects ; immunology ; Environmental Monitoring ; Humans ; Immunoglobulin G ; blood ; immunology ; Japan ; Male ; Manufacturing and Industrial Facilities ; statistics & numerical data ; Middle Aged ; Occupational Diseases ; blood ; chemically induced ; Occupational Exposure ; adverse effects ; statistics & numerical data ; Phthalic Anhydrides ; immunology ; toxicity ; Respiratory Hypersensitivity ; blood ; chemically induced ; Toluene 2,4-Diisocyanate ; immunology ; toxicity ; Workforce

2,4-dinitrophenol (DNP), an organic compound which frequently used in industry, is considered to have high toxicity. This study aimed to investigate the early changes of lymphocyte subpopulations in patients with occupational 2,4-DNP poisoning. Totally 9 patients with acute occupational 2,4-DNP poisoning and 30 healthy volunteers as control were enrolled. The patients received immediately comprehensive supportive treatments, including large-dose glucocorticoid and repeated hemoperfusion (HP). The ratio of CD4+/CD8+ T cells were significantly higher in patients upon admission compared to healthy controls (P < 0.01); however, counts of total lymphocytes, CD3+, CD3+CD4+, CD3+CD8+, B (CD19+), and natural killer (NK) cells (CD16+CD56+) were significantly reduced (all P < 0.001). The NK cell count was negatively correlated with initial plasma 2,4-DNP concentration (r = -0.750, P = 0.026). Thus, acute occupational 2,4-DNP poisoning was accompanied by immediate complex immune cell reactions, especially NK cells might play important role in severe 2,4-DNP poisoning.
2,4-Dinitrophenol ; poisoning ; toxicity ; Adult ; China ; Coloring Agents ; poisoning ; toxicity ; Female ; Humans ; Killer Cells, Natural ; drug effects ; Lymphocyte Subsets ; drug effects ; Male ; Middle Aged ; Occupational Diseases ; chemically induced ; T-Lymphocytes ; drug effects

To determine the correlation between the working environment and the health status of employees in solar greenhouse, 1171 employees were surveyed. The results show the 'Greenhouse diseases' are affected by many factors. Among general uncomforts, the morbidity of the bone and joint damage is the highest and closely related to labor time and age. Planting summer squash and wax gourd more easily cause skin pruritus. Asthma-related cough, eye disease, and skin pruritus are significantly correlated with the cultivation of wax gourd. The application of inorganic fertilizer and fertigation dramatically induce the bone and joint damage. The smell of covering film greatly influence skin pruritus. Personal protection is badly scanty and normative occupational health and safety need to be completed.
Adult ; Asthma ; chemically induced ; Cough ; chemically induced ; Crops, Agricultural ; Educational Status ; Environment, Controlled ; Eye Diseases ; chemically induced ; Fertilizers ; toxicity ; Humans ; Middle Aged ; Nose Diseases ; chemically induced ; Occupational Exposure ; Pesticides ; toxicity ; Pruritus ; chemically induced ; Risk Factors ; Stomach Diseases ; chemically induced ; Workplace

OBJECTIVETo understand the toxic effects of manganese exposure on health by measurement of manganese concentration and occupational health inspection among workers in an enterprise exposed to manganese, and to provide a basis for occupational disease control.

METHODSThe air concentrations of manganese in 12 workplaces where workers often stayed were measured by typical sampling; occupational health inspection was performed among a total of 538 workers in the enterprise by cluster sampling.

RESULTSThe average concentrations of manganese in the workplace from 2011 to 2013 were 0.179 mg/m(3), 0.122 mg/m(3), and 0.082 5 mg/m(3), respectively, indicating a significant decrease in manganese level within the three years by rank-sum test (P < 0.05). The results of health inspection showed that 165 (30.7%) out of 538 workers had abnormal indices, and the incidence of autonomic nervous system abnormalities reached 32.7% (176/538). There was no correlation between manganese concentration in the workplace and the incidence of abnormal indices in health inspection, while the manganese concentration in the workplace was positively correlated with the incidence of autonomic nervous system symptoms (r = 0.718, P < 0.05).

CONCLUSIONThe manganese concentration in the workplace is positively correlated with the incidence of autonomic nervous system symptoms. Early exposure to a low level of manganese can induce functional changes and potential damages in the nervous system.

Humans ; Incidence ; Manganese ; analysis ; Nervous System ; drug effects ; physiopathology ; Occupational Diseases ; chemically induced ; epidemiology ; Occupational Exposure ; analysis ; Occupational Health ; standards ; Workplace

Benzene ; poisoning ; Chronic Disease ; Humans ; Occupational Diseases ; chemically induced ; Occupational Exposure ; adverse effects

OBJECTIVETo investigate atmospheric mercury concentration in the workplace and urinary mercury concentration in workers exposed to mercury in a thermometer factory, and to determine the levels and influencing factors of urinary Β₂-microglobulin (Β₂-MG) and retinol-binding protein (RBP) in these workers.

METHODSAn occupational health survey of the workplace was completed according to relevant national occupational health standards. Questionnaire survey and occupational health examination were conducted in 178 workers exposed to mercury in the factory. Statistical analysis was accomplished using SPSS 19.0.

RESULTSIn the workplace, atmospheric mercury concentration was out of limits at seven of eight detection points expressed by short-term exposure limit; it was out of limits at all the eight detection points shown by time-weighted average. Statistically significant difference in atmospheric mercury concentration was found among different detection points (F = 138.714, P < 0.001). The geometric mean of urinary mercury concentration measured in 154 workers was 171.607 µg/g. There were 127 workers with urinary mercury concentration exceeding the standard (82.5% over-standard rate). Significant difference in urinary mercury concentration was shown in the workers among different positions (χ² = 44.531, P < 0.01). Urinary mercury concentration was positively correlated with atmospheric mercury concentration (r = 0.624, P < 0.01). The mean urinary Β₂-MG level measured in 148 workers was 0.142 mg/L, and seven workers had urinary Β₂-MG levels greater than 0.3 mg/L (4.7% abnormal rate). The mean urinary RBP level measured in 153 workers was 0.485 mg/L, and 19 workers had urinary RBP levels greater than 0.7 mg/L (12.4% abnormal rate). Ordinal logistic regression showed that age >34 years (OR = 4.88, 95%CI: 2.24∼10.62) and length of service >15 years (OR = 2.50, 95%CI: 1.06-5.92) were risk factors for increased urinary Β₂-MG level. Age >45 years (OR = 7.52, 95%CI: 2.50∼22.65) was a risk factor for increased urinary RBP level.

CONCLUSIONIn the thermometer factory under study, atmospheric and urinary mercury concentrations both seriously exceeded the standards, which were harmful to the health of workers. High atmospheric mercury concentration, old age, and long length of service were risk factors for increased urinary Β₂-MG and RBP levels in workers exposed to mercury.

Adult ; Environmental Exposure ; Humans ; Kidney ; drug effects ; Kidney Diseases ; chemically induced ; Mercury ; analysis ; toxicity ; Occupational Exposure ; Risk Factors ; Threshold Limit Values ; Time Factors ; Workplace

Adult ; Bis(Chloromethyl) Ether ; poisoning ; Humans ; Lung Neoplasms ; chemically induced ; Male ; Middle Aged ; Occupational Diseases ; chemically induced

OBJECTIVETo investigate the health status of painting and coating workers in an automobile manufacturing enterprise in Guangzhou, China and analyze the influential factors for the health status of these workers, and to provide health intervention measures and strategies.

METHODSTypical sampling was used to select an automobile manufacturing enterprise; according to whether the subjects were in contact with paint and coatings, paint spraying workers in the painting workshop were selected as the exposed group, and the staff in the administration, procurement, and marketing departments as the control group. Physical examination was performed by doctors among these subjects.

RESULTSThe exposed group had significantly higher positive rates of dizziness, headache, bleeding gums, chest tightness, and skin itching than the control group (P < 0.05). The exposed group had a nonsignificantly higher rate of abnormal ECG than the control group (P > 0.05), but the exposed group had a significantly higher incidence of various blocks (P = 0.020) and significantly lower leukocyte count, erythrocyte count, and male workers' hemoglobin level (P < 0.05), as compared with the control group.

CONCLUSIONVolatile organic solvents have adverse effect on the health of paint spraying workers in the automobile manufacturing enterprise, so regular physical examination should be performed to strengthen health interventions and improve health.

Adult ; Automobiles ; Female ; Health Status ; Humans ; Male ; Occupational Diseases ; chemically induced ; Occupational Exposure ; adverse effects ; Paint ; adverse effects ; Volatile Organic Compounds ; adverse effects