Assessment of Occupational Exposure to Indium Dust for Indium-Tin-Oxide Manufacturing Workers.

According to recent research, indium nanoparticles (NPs) are more toxic than micro-sized particles. While cases of indium lung disease have been reported worldwide, very little research has been conducted on the occupational exposure to indium NPs. Recently, an indium-related lung disease was reported in Korea, a global powerhouse for display manufacturing. In this study, we conducted an assessment ofoccupational exposure at an indium tin oxide (ITO) powder manufacturing plant, where the first case of indium lung disease in Korea occurred. Airborne dustwas obtained from a worker's breathing zone, and area sampling in the workplace environment was conducted using real-time monitoring devices. Personal samples were analyzed for the indium concentrations in total dust, respirable dust fraction, and NPs using personal NPs respiratory deposition samplers. The total indium concentration of the personal samples was lower than the threshold limit value recommended by the American Conference of Governmental Industrial Hygienists (ACGIH TLV), which was set as occupational exposure limit (OEL). However, the respirable indium concentration exceeded the recently set ACGIH TLV for the respirable fraction of indium dust. The concentration of indium NPs ranged between 0.003 and 0.010 × 10-2 mg/m3, accounting for only 0.4% of the total and 2.7% of the respirable indium particles. This was attributed to the aggregating of NPs at the µm sub-level. Given the extremely low fraction of indium NPs in the total and respirable dust, the current OEL values, set as the total and respirable indium concentrations, do not holistically represent the occupational exposure to indium NPs or prevent health hazards. Therefore, it is necessary to set separate OEL values for indium NPs. This study covers only the process of handling ITO powder. Therefore, follow-up studies need to be conducted on other ITO sputtering target polishing and milling processes, which typically generate more airborne NPs, to further investigate the effects of indium on workers and facilitate the necessary implementation of indium-reducing technologies.

The scope and specific criteria of compensation for occupational diseases in Korea.

The range of diseases covered by workers' compensation is constantly expanding. However, new regulations are required for the recognition of occupational diseases (ODs) because OD types evolve with changes in industrial structures and working conditions. OD criteria are usually based on medical relevance, but they vary depending on the social security system and laws of each country. In addition, the proposed range and extent of work-relatedness vary depending on the socio-economic conditions of each country. The Labor Standards Act (LSA) and the Industrial Accident Compensation Insurance Act (IACIA) of Korea employ lists based on their requirements without listing causes and diseases separately. Despite a considerable reshuffle in 2003, the basic framework has been maintained for 50 yr, and many cases do not fit into the international disease classification system. Since July 1, 2013, Korea has expanded the range of occupational accidents to include occupational cancers and has implemented revised LSA and IACIA enforcement decrees. There have been improvements to OD recognition standards with the inclusion of additional or modified criteria, a revised and improved classification scheme for risk factors and ODs, and so on.

A case report of lung cancer in a horse trainer caused by exposure to respirable crystalline silica: an exposure assessment.

Here, we present a case of lung cancer in a 48-year-old male horse trainer. To the best of our knowledge, this is the first such case report to include an exposure assessment of respirable crystalline silica (RCS) as a quartz. The trainer had no family history of lung cancer. Although he had a 15 pack/year cigarette-smoking history, he had stopped smoking 12 years prior to his diagnosis. For the past 23 years, he had performed longeing, and trained 7-12 horses per day on longeing arena surfaces covered by recycled sands, the same surfaces used in race tracks. We investigated his workplace RCS exposure, and found it to be the likely cause of his lung cancer. The 8-hour time weight average range of RCS was 0.020 to 0.086 mg/m(3) in the longeing arena. Horse trainers are exposed to RCS from the sand in longeing arenas, and the exposure level is high enough to have epidemiological ramifications for the occupational risk of lung cancer.

Health risk assessment of exposure to chlorpyrifos and dichlorvos in children at childcare facilities.

The present study evaluated 168 childcare facilities from 6 cities in South Korea to assess exposure to organophosphorus pesticides (OPs) in children through 4 major pathways (indoor air, indoor dust, surface wipe of indoor objects, and hand wash water of children). The Excess Cancer Risk (ECR) was calculated based on the Cancer Potency Factor (CPF) and Age Dependent Adjustment Factor (ADAF) in adults. Dichlorvos residues were detected in the indoor air, indoor dust, surface wipes of indoor objects, and the hand wash water of children at frequencies of 47.4, 90, 100, and 100%, respectively. After revision based on the ADAF, total cancer risk in the 50th percentile was 3.99×10(-3) for inhalation, oral intake, and dermal contact in children ages 3 to 4 and 4.63×10(-4) in kindergarteners ages 5 to 6. Inhalation was the primary pathway of pesticide exposure in children in childcare facilities. Children ages 3 to 4 in daycare centers had a Hazard Quotient (HQ) of 0.5 for dichlorvos, which was 50% lower than the risk criterion level of 1 but was higher than the 95% percentile with a HQ of 1.9. This study postulates that children in childcare facilities may be exposed to specific OPs.

Exposure assessment suggests exposure to lung cancer carcinogens in a painter working in an automobile bumper shop.

A 46-year-old man who had worked as a bumper spray painter in an automobile body shop for 15 years developed lung cancer. The patient was a nonsmoker with no family history of lung cancer. To determine whether the cancer was related to his work environment, we assessed the level of exposure to carcinogens during spray painting, sanding, and heat treatment. The results showed that spray painting with yellow paint increased the concentration of hexavalent chromium in the air to as much as 118.33 µg/m(3). Analysis of the paint bulk materials showed that hexavalent chromium was mostly found in the form of lead chromate. Interestingly, strontium chromate was also detected, and the concentration of strontium chromate increased in line with the brightness of the yellow color. Some paints contained about 1% crystalline silica in the form of quartz.

Risk Assessment of Baby Powder Exposure through Inhalation.

This study was conducted to assess the exposure risk through inhalation to baby powder for babies and adults under simulated conditions. Baby powder was applied to a baby doll and the amount of baby powder consumed per application was estimated. The airborne exposure to baby powder during application was then evaluated by sampling the airborne baby powder near the breathing zones of both the baby doll and the person applying the powder (the applicator). The average amount of baby powder consumed was 100 mg/application, and the average exposure concentration of airborne baby powder for the applicator and baby doll was 0.00527 mg/m(3) (range 0.00157~0.01579 mg/m(3)) and 0.02207 mg/m(3) (range 0.00780~ 0.04173 mg/m(3)), respectively. When compared with the Occupational Exposure Limit of 2 mg/m(3) set by the Korean Ministry of Labor and the Threshold Limit Value (TLV) of 2 mg/m(3) set by the ACGIH (American Conference of Governmental Industrial Hygienists), the exposure concentrations were much lower. Next, the exposure to asbestos-containing baby powder was estimated and the exposure risk was assessed based on the lung asbestos contents in normal humans. As a result, the estimated lung asbestos content resulting from exposure to asbestos-containing baby powder was found to be much lower than that of a normal Korean with no asbestos-related occupational history.