Evaluation of Respiratory Protection Program in Petrochemical Industries: Application of Analytic Hierarchy Process

BACKGROUND: Respiratory protection equipment (RPE) is the last resort to control exposure to workplace air pollutants. A comprehensive respiratory protection program (RPP) ensures that RPE is selected, used, and cared properly. Therefore, RPP must be well integrated into the occupational health and safety requirements. In this study, we evaluated the implementation of RPP in Iranian petrochemical industries to identify the required solutions to improve the current status of respiratory protection. METHODS: This cross-sectional study was conducted among 24 petrochemical industries in Iran. The survey instrument was a checklist extracted from the Occupational Safety and Health Administration respiratory protection standard. An index, Respiratory Protection Program Index (RPPI), was developed and weighted by analytic hierarchy process to determine the compliance rate (CR) of provided respiratory protection measures with the RPP standard. Data analysis was performed using Excel 2010. RESULTS: The most important element of RPP, according to experts, was respiratory hazard evaluation. The average value of RPPI in the petrochemical plants was 49 ± 15%. The highest and lowest of CR among RPP elements were RPE selection and medical evaluation, respectively. CONCLUSION: None of studied petrochemical industries implemented RPP completely. This can lead to employees' overexposure to hazardous workplace air contaminants. Increasing awareness of employees and employers through training is suggested by this study to improve such conditions.

Review of carcinogenicity of hexavalent chrome and proposal of revising approval standards for an occupational cancers in Korea

BACKGROUND: The objective of this study is to suggest revised recognition standards for occupational disease due to chromium (VI) by reflecting recent domestic and international research works and considering domestic exposure status with respect to target organs, exposure period, and cumulative exposure dose in relation to the chromium (VI)-induced occupational disease compensation. METHODS: In this study, the reports published by major international institutions such as World Health Organization (WHO) International Agency for Research on Cancer (IARC) (2012), Occupational Safety and Health Administration (OSHA) (2006), National Institute for Occupational Safety and Health (NIOSH) (2013), American Conference of Governmental Industrial Hygienists (ACGIH) (2004), National Toxicology Program (NTP) (2014), and Agency for Toxic Substances and Disease Registry (ASTDR) (2012) were reviewed and the recent research works searched by PubMed were summarized. RESULTS: Considering the recent research works and the domestic situation, only lung cancer is conserved in the legislative bill in relation to chromium (VI), and the exposure period is not included in the bill. Nasal and paranasal sinus cancer was excluded from the list of cancers that are compensated as the chromium (VI)- induced occupational disease, while lung cancer remains in the list. In the view of legislative unity, considering the fact that only the cancers having sufficient evidence are included in the conventional list of cancers compensated as occupational disease, nasal and paranasal sinus cancer having limited evidence were excluded from the list. The exposure period was also removed from the legislative bill due to the insufficient evidence. Recent advices in connection with cumulative exposure dose were proposed, and other considerable points were provided with respect to individual occupational relevance. CONCLUSIONS: It is suggested that the current recognition standard which is “Lung cancer or nasal and paranasal sinus cancer caused by exposure to chromium (VI) or compounds thereof (exposure for two years or longer), or nickel compounds” should be changed to “Lung cancer caused by exposure to chromium (VI) or compounds thereof, and lung cancer or nasal and paranasal sinus cancer caused by exposure to nickel compounds”.

Noise Exposure Assessment in a Dental School

OBJECTIVES: This cross-sectional study was performed in the Dental School of Prince of Songkla University to ascertain noise exposure of dentists, dental assistants, and laboratory technicians. A noise spectral analysis was taken to illustrate the spectra of dental devices. METHODS: A noise evaluation was performed to measure the noise level at dental clinics and one dental laboratory from May to December 2010. Noise spectral data of dental devices were taken during dental practices at the dental services clinic and at the dental laboratory. A noise dosimeter was set following the Occupational Safety and Health Administration criteria and then attached to the subjects' collar to record personal noise dose exposure during working periods. RESULTS: The peaks of the noise spectrum of dental instruments were at 1,000, 4,000, and 8,000 Hz which depended on the type of instrument. The differences in working areas and job positions had an influence on the level of noise exposure (p < 0.01). Noise measurement in the personal hearing zone found that the laboratory technicians were exposed to the highest impulsive noise levels (137.1 dBC). The dentists and dental assistants who worked at a pedodontic clinic had the highest percent noise dose (4.60 +/- 3.59%). In the working areas, the 8-hour time-weighted average of noise levels ranged between 49.7-58.1 dBA while the noisiest working area was the dental laboratory. CONCLUSION: Dental personnel are exposed to noise intensities lower than occupational exposure limits. Therefore, these dental personnel may not experience a noise-induced hearing loss.

Comparison of the Standard Threshold Shift Criteria for Evaluating Hearing Conservation Programs / 대한산업의학회지

OBJECTIVES: Workers from a factory was selected to compare 8 standard threshold shift criteria with the Korean diagnostic criteria of noise-induced hearing loss for this cohort study. METHODS: From 1990 to 1999, 491 workers at a manufacturing company with complete record of the hearing test covering the range of 0.5~6 kHz for 10 consecutive years were finally selected. Eight standard threshold shift criteria (15 dB once, NIOSH (1972), 10 dB average 3~4 kHz, OSHA STS, AAOHNS, 15 dB twice, 15 dB 1~4 kHz, OSHA STS twice) along with the Korean standard for diagnosing the noise-induced hearing loss (the average hearing threshold at 0.5, 1 and 2 kHz) were compared to calculate the degree of the threshold shift and the minimum time required to detect the change. RESULTS: Those workers showing at least one positive shift in the 'once'criteria of NIOSH (1972) were 92.5%; the 'average'criteria of 10 dB average 3~4 kHz were 35.8%; 'twice'criteria of 15 dB twice were 44.4%. The duration from the baseline to the year showing the first positive shift was from 3.2 +/- 3.1 years (NIOSH, 1972) to 6.0 +/- 2.1 years (OSHA STS twice). The percentage of true positive shift ranging from 20.4% (AAO-HNS) to 69.8% (NIOSH, 1972). There were 10 (2%) which met the Korean diagnostic criteria of noise-induced hearing loss. CONCLUSIONS: Currently the concept of hearing threshold shift in diagnosing the hearing loss was adopted in Korea thus in this study we determined the validity and the effect of the various hearing threshold shift criteria and showed that NIOSH (1972) criteria was the best of all. In the future, hearing data from various manufacturing workers should be compared to thoroughly evaluate the threshold shift criteria and to establish adequate standard for Korean workers.

Usefulness of High Resolution Computed Tomography (HRCT) in the Diagnosis of Asbestos-Related Lung Diseases / 대한산업의학회지

OBJECTIVES: This study was carried out to improve the medical surveillance program of workers exposed to asbestos by examining the usefulness of High Resolution Computed Tomography (HRCT) in the diagnosis of asbestos-related lung disease. METHODS: The study subjects comprised 162 workers in a ship-repairing yard, 68 of whom had been directly exposed to asbestos and 94 indirectly exposed. The 'Occupational Safety & Health Administration (OSHA) asbestos standard, medical surveillance program' and HRCT were conducted to analyze the aspects of the asbestos-related lung disease. The OSHA asbestos standard, medical surveillance program consists of simple chest x-ray, spirometry and medical questionnaire. RESULTS: Seventeen (10.5%) of the 162 subjects, 10 (14.7%) directly exposed and 7 (7.4%) indirectly exposed, revealed asbestos-related lung disease on HRCT. The sensitivity and specificity of simple chest x-ray for asbestos-related lung disease were 70.6% and 98.6%, and the positive and negative predictive values were 85.7% and 96.6% respectively, as compared with HRCT. HRCT was an effective diagnostic tool especially to detect early asbestos-related lung disease. The study results indicated a relative significant association between the results of spirometry and HRCT. The variables significantly associated with asbestos-related lung disease on HRCT were work duration, smoking history (pack-years), past history of respiratory disease, cough and dyspnea. CONCLUSIONS: In the diagnosis of asbestos-related lung disease, HRCT should be considered not only for workers with positive findings on simple chest x-ray, but also workers with specific findings on spirometry, occupational history, smoking history, and past history of respiratory disease, or with respiratory symptoms such as cough and dyspnea.

Ambient Noise Levels in the Audiometric Test Rooms Used for Special Periodic Health Examination / 대한산업의학회지

OBJECTIVES: The ambient noise levels in the test rooms affect the workers's hearing threshold. The present study was designed to assess the ambient noise levels in the test rooms to determine if valid hearing tests, both pure-tone air conduction and bone-conduction, could be performed in these environments. METHODS: In the present study, third octave band ambient noise sound pressure levels were measured in 124 audiometric test rooms used for clinical audiometry, and the results were compared with the ANSI third octave band maximum permissible ambient noise levels (MPANLs) for each test condition and frequency range. RESULTS: The ambient noise SPLs were highest in the lower frequencies, and this decreased as the frequency increased. For the "ears covered"condition, about 24.2% of the rooms were in compliance (pass) with the MPANLs for the 125-8000 Hz, 35.5% were in compliance for the 250-8000 Hz range and 55.6% were in compliance for the 500-8000 Hz range. For the "ears not covered"condition, only about 8.1% of the rooms passed for the 125-8000 Hz, 13.7% of the rooms passed for the 250-8000 Hz range and 34.7% of the rooms passed for the 500-8000 Hz range. All 124 rooms met the OSHA MPANLs. CONCLUSIONS: The results of this study strongly indicate that clinical audiometry is being conducted in test rooms having unacceptable or excessive ambient noise levels.

Halitosis en pacientes con problemas periodontales / Halitosis in patients with periodontal problems

La halitosis es una condición frecuente, que todas las personas en algún momento de su vida padecen, el odontólogo es el profesional más ligado con este problema. El objetivo de este estudio fue determinar la asociación entre la halitosis y la severidad de la enfermedad periodontal. Se realizó un estudio transversal descriptivo en donde se evaluaron 200 pacientes cuyo motivo de consulta fue la halitosis. Se utilizó un alímetro para medir los compuestos volátiles de sulfuro (CVS) y se determinó la asociación con enfermedad periodontal. El 19.3 por ciento de los pacientes con halitosis presentan enfermedad periodontal, el 43.2 por ciento problemas sistémicos asociados, y el 6 por ciento problemas emocionales. En el 31.5 por ciento, la cantidad de CVS fue menor a 300 partes por billón (ppb)

Survey on the Prevalence of Carpal Tunnel Syndrome in Simple Repetitive Workers Who Use Upper Extremities / 대한산업의학회지

OBJECTIVES: This study was carried out to survey on the prevalence of Carpal Tunnel Syndrome(CTS) in high risk jobs(meat and fish processing plant and wood plant), by application of Nerve Conduction Study(NCS), a confirmatory diagnostic method. METHODS: Experimental group was 69 workers sampled from meat and fish processing plants and 17 workers sampled from wood plants, who were simple, repetitive workers using upper extremities and control group was 28 workers sampled from managers, secretaries and keepers. All employees were examined through work history, physical examination and NCS. RESULTS: 18 workers(26.09%) in meat and fish processing plants, and 5 workers(29.41%) in wood plants had compatible findings to NIOSH diagnostic criteria for CTS. The experimental group had more symptoms(complaint of upper extremities, Visual Analogue Scale >or= 4(VAS: total 10 point)), signs(Tinel and Phalen test) and prevalence of CTS than control group ( por=7 years). CONCLUSIONS: The prevalence of CTS in meat and fish processing plant and wood plant were 26.09% and 29.41% respectively. Authors propose that meat and fish processing and wood plants should be managed as a risk job category which were designated by OSHA in 1996

Evaluation method for vinyl chloride exposed workers

BACKGROUND: This study was conducted to evaluate vinly chloride exposure in vinyl chloride and poly vinyl chloride manufacturing factories. The object of this study was compare two different type of air sampling method that of, NIOSH and OSHA recommended and Investigate quantitative correlation between level of vinyl chloride exposure and urinary thiodiglycolic acid excretion. METHODS: Air sampling was conducted by two method and sampling mediums were located at workers breathing zone in the same location. Sampling mediums were changed in 60 minute interval and sampling pumps were recalibrated at the same time. Urine was collected before and end of shift were stored frozen and determined by GC/FID analysis. RESULTS: In NIOSH method, time weighted average was 3.562 +/- 2.898 ppm and OSHA method time weighted average was 4.051 +/- 3.700 ppm. Concentration of urinary TdGA in before shift was 0.527 +/- 0.828 g/g creatinine and end of shift was 4.190 +/- 7.665 mg/g creatinine. Difference of urinary TdGA between end of shift to before shift was 3.662 +/- 7.865 mg/g creatinine. In NIOSH method, correlation coefficient between 8hour-time weighted average (8hrs-TWA) and urinary concentration of TdGA was r=0.666. and last period vinyl chloride level (6th-TWA) and urinary TdGA concentration was r=0.972. In OSHA method, correlation coefficient between last period vinyl chloride level (6th-TWA) and urinary concentration of TdGA was r=0.976 and this was highest value. CONCLUSION: There was no statistically significant difference in NIOSH method and. OSHA method. A correlation were found between level of vinyl chloride exposure and urinary thiodiglycolic acid excretion. Also, vinyl chloride exposure had significantly effected on the urinary thiodiglycolic acid excretion.