Biomedical subjects

Dong-Uk Park

Publications and source records attributed to Dong-Uk Park.

3 recordsLinked to original sources

PubMed2006

Selecting high-risk micro-scale enterprises using a qualitative risk assessment method.

Micro-scale enterprises (MSEs) with less than 5 employees are subject to be covered by the scheme of the regular workplace environmental inspection and medical health examination from 2002 in Korea. Due to limited resources as well as vast number of enterprises to be covered, there is an urgent need to focus these efforts to only those high-risk MSEs. To identify them, a qualitative risk assessment methodology was developed combining the hazardous nature of chemicals and exposure potentials as modeled by the HSE and the risk categorization technique by the AIHA. Risk Index (RI) was determined by combining characteristics specific to chemicals and scale of use of the chemicals. The method was applied to 514 MSEs that were selected from a random sample of 4000 MSEs. A total of 170 out of 514 MSEs studied were included in the final analysis. Current status and characteristics of MSEs were identified and RI was assigned to chemicals in each industry. Based on the distribution of RIs, the high-risk MSEs were selected. These include: wood and products of wood, chemicals and chemical products, basic metals, other machinery and equipment, motor vehicles, trailer and semi-trailer manufacturing, and furniture manufacturing. Since these MSEs are high-risk ones, more attentions should be focused on them. This method can be applied to other workplaces with no previous history of quantitative workplace inspections.

Commerce↗

PubMed2002

Effect on blood lead of airborne lead particles characterized by size.

Worker exposure to airborne lead particles was evaluated for a total of 117 workers in 12 work-places of four different industrial types in Korea. The particle sizes were measured using 8-stage cascade impactors worn by the workers. Mass median aerodynamic diameters (MMAD) were determined by type of industry and percentage of lead particles as a fraction of airborne lead (PbA) concentration was determined by particle size. Blood lead (PbB) levels of workers who matched airborne lead samples were also examined. A Scheffé's pairwise comparison test showed that MMAD and the fractions of each of respirable particles and lead particles < or =1 microm relative to PbA varied greatly by the type of industry. The concentrations of lead particles < or =1 microm, which the Center for Policy Alternatives model assumes is relatively constant at 12.5 microg/m3, increased with increasing PbA concentration. In addition, a better correlation was detected between concentrations of particles < or =1 microm and concentrations of respirable lead particles (r = 0.82) than that between concentrations of small particles and PbA (r = 0.61). A simple linear regression indicated that PbB correlated better with respirable lead concentration (r2 = 0.35, P = 0.0001) than with PbA concentration and had a higher slope coefficient. Controlling for respirable lead concentration reduced the partial correlation coefficient between PbA concentration and PbB level from 0.56 to 0.20 (P = 0.053). The results indicate that the contribution of respirable lead particles to lead absorption would be greater than that of PbA. This study concludes that the measurement of PbA only may not properly reflect a worker's exposure to lead particles with diverse characteristics. For the evaluation of a worker's exposure to various types of lead particles, it is recommended that respirable lead particles as well as PbA be measured.

Aerosols↗

PubMedDate not supplied

Loss of straight metalworking fluid samples from evaporation during sampling and desiccation.

Straight metalworking fluids (MWFs) were used to evaluate the potential for the loss of MWF mass from filters. Two methods were used to study the stability of MWF mass on filter media. The first was to spike known amounts of MWF onto polyvinyl chloride (PVC) filters, store the filters over silica gel desiccant, and take repeated gravimetric measurements of the filters at intervals of 1, 2, and 3 days. An MWF aerosol mist was generated in a test chamber and collected on PVC filters for the second experimental method. Additional clean air was drawn through a subset of filters (range 0.02-0.48 m(3)), which were then stored over silica gel prior to weighing. Losses due to desiccation were found in filters that had not been exposed to airflow, as well as for filters after aspiration. The losses occurring in spiked filters (range of mean 2.6-15.2%) were higher than those in collected filters (range 0.7-8.1%). The MWF aerosol mass collected on PVC filters decreased with the increasing volume of clean air passing through the filter. In a multiple regression model, to predict the loss of collected MWF due to desiccation, loading mass, fresh MWF, and air passing time of 10 min were significant predictors (p=.0001, R(2)=.374). In particular, only air passage of 10 min was significantly higher (2.13%) than the reference air passage (p=.0054). The investigators concluded that MWF aerosol collected on PVC filters may be lost to evaporation under conditions typical of shipment, storage, and desiccation of sample filters, and with airflow through the filter.

Aerosols↗