OCCUPATIONAL CANCER BURDEN: THE CONTRIBUTION OF EXPOSURE TO PROCESS-GENERATED SUBSTANCES AT THE WORKPLACE

Occupational exposure to respirable crystalline silica, diesel engine exhaust emissions and welding fumes are widespread risk factors for lung cancer, and account for approximately half of the occupational lung cancer burden. If employers succeed in controlling workplace exposures to these process-generated substances, the fraction of lung cancers attributable to occupational exposures could be reduced dramatically.

Epigenetic-Based Biomarkers in the Malignant Transformation of BEAS-2B Cells Induced by Coal Tar Pitch Extract

Background and objectives: The carcinogenicity of coal tar pitch (CTP) to occupational workers has been confirmed by the International Agency for Research on Cancer, especially for lung cancer. Herein, we explored the dynamic changes of epigenetic modifications in the malignant transformation process of CTP-induced BEAS-2B cells and also provided clues for screening early biomarkers of CTP-associated occupational lung cancer. Methods: BEAS-2B cells treated with 3.0 μg/mL CTP extract (CTPE) were cultured to the 30th passage to set up a malignant transformation model, which was confirmed by platelet clone formation assay and xenograft assay. DNA methylation levels were determined by ultraviolet-high performance liquid chromatography. mRNA levels in cells and protein levels in supernatants were respectively detected by Real-Time PCR and enzyme-linked immunosorbent assay. Results: The number of clones and the ability of tumor formation in nude mice of CTPE-exposed BEAS-2B cells at 30th passage were significantly increased compared to vehicle control. Moreover, genomic DNA methylation level was down-regulated. The mRNA levels of DNMT1, DNMT3a and HDAC1 as well as the expression of DNMT1 protein were up-regulated since the 10th passage. From the 20th passage, the transcriptional levels of DNMT3b, let-7a and the expression of DNMT3a, DNMT3b, and HDAC1 proteins were detected to be higher than vehicle control, while the level of miR-21 increased only at the 30th passage. Conclusion: Data in this study indicated that the changes of epigenetic molecules including DNMT1, DNMT3a, DNMT3b, HDAC1, and let-7a occurred at the early stages of BEAS-2B cell malignant transformation after CTPE exposure, which provided critical information for screening early biomarkers of CTP-associated occupational lung cancer.

Exposure assessment of elemental carbon, ultrafine particles, and crystalline silica at highway toll booths

Highway toll booth workers have been reported to be at an increased risk of occupational lung cancer. Moreover, insufficient studies have been performed on exposure assessment of workers at highway toll booths. Elemental carbon (EC), black carbon (BC), and respirable crystalline silica (RCS) concentrations were measured at highway toll booths in Gyeongsangbuk-do (Republic of Korea). The particle number (PN) concentration and size distribution of ultrafine particle were measured using three SMPS devices. The average concentration of the EC inside the booth was 3.3 μg/m³, with the maximum being 5.8 μg/m³. The concentrations of EC were highest for booths that operated exclusively for trucks. The average PN concentration inside the booth was 3.54 × 10⁴ cm^-3, approximately 5-fold higher than the reference indoor background. The average BC concentration in the booths were approximately 8 μg/m³, and the instantaneous peak concentration was 271 μg/m³. The RCS was below the detection limit in all samples. This study revealed that toll workers were most frequently exposed to diesel engine particle less than 100 nm, with an extremely high respiratory deposition rate. Therefore, a respiratory protection program is necessary to safeguard these workers against vehicle-related pollutants.

Radiation Examination of Newborns with General Therapeutic Hypothermia

Purpose: Search of possible criteria of the diagnosis of occupational lung cancer in workers of uranium mines on the basis of the analysis of literary data. Material and methods: The analysis of literary data with the purpose of allocation of possible criteria and their use for the diagnosis of occupational lung cancer at 6 employees of uranium mines. Results: The following criteria for the diagnosis of occupationally caused lung cancer at workers of uranium mines are marked out: • Total effective dose of radiation exposure is more 200–250 mSv (40–50 WLM). • Period in underground conditions is not less than 10 years. • Dust content in a workplace is more than 1 mg/m3. • Hygienic assessment of working conditions – the 3rd class, 3.2–3.4 degree. • The latent period of development of a tumor is not less 10 years. • Development of primary and multiple synchronous or metachronous lung cancer. Also the diagnosis of occupational lung cancer the pulmonary anamnesis (frequent bronchitis, pneumonia, chronic bronchitis of the smoker) has to be considered. On the basis of the marked-out criteria documents of 6 employees of uranium mines, at which lung cancer has been revealed, are considered. On the basis of the carried-out analysis at 5 patients relation of a disease with professional activity has been established. One patient was denied this relation. Conclusion: Authors offer this expert approach to experts’ discussion as above-mentioned criteria is planned to be used by the pathologists who are carrying out observation of workers of uranium production and for the solution of questions of relation of a disease with professional activity of the patient.

Possible Criteria of the Diagnosis of Occupational Lung Cancer in Workers of Uranium Mines

Purpose: Search of possible criteria of the diagnosis of occupational lung cancer in workers of uranium mines on the basis of the analysis of literary data. Material and methods: The analysis of literary data with the purpose of allocation of possible criteria and their use for the diagnosis of occupational lung cancer at 6 employees of uranium mines. Results: The following criteria for the diagnosis of occupationally caused lung cancer at workers of uranium mines are marked out: • Total effective dose of radiation exposure is more 200–250 mSv (40–50 WLM). • Period in underground conditions is not less than 10 years. • Dust content in a workplace is more than 1 mg/m3. • Hygienic assessment of working conditions – the 3rd class, 3.2–3.4 degree. • The latent period of development of a tumor is not less 10 years. • Development of primary and multiple synchronous or metachronous lung cancer. Also the diagnosis of occupational lung cancer the pulmonary anamnesis (frequent bronchitis, pneumonia, chronic bronchitis of the smoker) has to be considered. On the basis of the marked-out criteria documents of 6 employees of uranium mines, at which lung cancer has been revealed, are considered. On the basis of the carried-out analysis at 5 patients relation of a disease with professional activity has been established. One patient was denied this relation. Conclusion: Authors offer this expert approach to experts’ discussion as above-mentioned criteria is planned to be used by the pathologists who are carrying out observation of workers of uranium production and for the solution of questions of relation of a disease with professional activity of the patient.