Study on Potential of Occupational Exposure Limits Harmonization in ASEAN-5 Countries

Five countries within the Association of South East Asian Nation (ASEAN-5), which consists of Indonesia, Malaysia, Singapore, Thailand, and Philippines, use a variety of chemicals in their industries and set Occupational Exposure Limit (OEL) as a regulation or reference instrument to control chemical. This study is aimed to assess the potential of OEL harmonization amongst ASEAN-5 since there is extensive labor exchange between South East Asian Region. Seven OELs (three lists from Indonesia) were compared between each other; and also, with TLV ACGIH 2016 and PEL OSHA as references. The geometric similarity measure (GSM) and non-metric multidimensional scaling plots were used for OEL similarities evaluation. There were a total of 713chemical substances in the list being compared; 40 common substances that were available in all OEL lists; and 73 unique substances that appear only in 1 list of OEL. In non-metric multidimensional scaling plots, it was found that 5 OEL have close similarities with both TLV ACGIH 2016 and PEL OSHA. Thailand-OEL and Regulationof Ministry of Health of Indonesia No. 70 of Year 2016 showed dissimilarity with TLV ACGIH 2016 and PEL OSHA 2016 due to having lesser number of substances. There was a potential of OEL harmonization within ASEAN-5 since some similarities in listed substances and concentration limit were found. Keywords: chemical substances, harmonization study, occupational exposure limit, regulatio

Uptake and depuration of gold nanoparticles in Daphnia magna

This study presents a series of short-term studies (total duration 48 h) of uptake and depuration of engineered nanoparticles (ENP) in neonate Daphnia magna. Gold nanoparticles (Au NP) were used to study the influence of size, stabilizing agent and feeding on uptake and depuration kinetics and animal body burdens. 10 and 30 nm Au NP with different stabilizing agents [citrate (CIT) and mercaptoundecanoic acid (MUDA)] were tested in concentrations around 0.5 mg Au/L. Fast initial uptake was observed for all studied Au NP, with CIT stabilized Au NP showing similar rates independent of size and MUDA showing increased uptake for the smaller Au NP (MUDA 10 nm > CIT 10 nm, 30 nm > MUDA 30 nm). However, upon transfer to clean media no clear trend on depuration rates was found in terms of stabilizing agent or size. Independent of stabilizing agent, 10 nm Au NP resulted in higher residual whole-animal body burdens after 24 h depuration than 30 nm Au NP with residual body burdens about one order of magnitude higher of animals exposed to 10 nm Au NP. The presence of food (P. subcapitata) did not significantly affect the body burden after 24 h of exposure, but depuration was increased. While food addition is not necessary to ensure D. magna survival in the presented short-term test design, the influence of food on uptake and depuration kinetics is essential to consider in long term studies of ENP where food addition is necessary. This study demonstrates the feasibility of a short-term test design to assess the uptake and depuration of ENP in D. magna. The findings underlines that the assumptions behind the traditional way of quantifying bioconcentration are not fulfilled when ENPs are studied.Peer reviewed: YesNRC publication: Ye

Controlling silver nanoparticle exposure in algal toxicity testing - A matter of timing

The aquatic ecotoxicity testing of nanoparticles is complicated by unstable exposure conditions resulting from various transformation processes of nanoparticles in aqueous suspensions. In this study, we investigated the influence of exposure timing on the algal test response to silver nanoparticles (AgNPs), by reducing the incubation time and by aging the AgNPs in algal medium prior to testing. The freshwater green algae Pseudokirchneriella subcapitata were exposed to AgNO(3), NM-300 K (a representative AgNP) and citrate stabilized AgNPs from two different manufacturers (AgNP1 and AgNP2) in a standard algal growth inhibition test (ISO 8692:2004) for 48 h and a short-term (2 h) (14)C-assimilation test. For AgNO(3), similar responses were obtained in the two tests, whereas freshly prepared suspensions of citrate stabilized AgNPs were less toxic in the 2-h tests compared to the 48-h tests. The 2-h test was found applicable for dissolved silver, but yielded non-monotonous concentration–response relationships and poor reproducibility for freshly prepared AgNP suspensions. However, when aging AgNPs in algal medium 24 h prior to testing, clear concentration–response patterns emerged and reproducibility increased. Prolonged aging to 48 h increased toxicity in the 2-h tests whereas aging beyond 48 h reduced toxicity. Our results demonstrate that the outcome of algal toxicity testing of AgNPs is highly influenced not only by the test duration, but also by the time passed from the moment AgNPs are added to the test medium. This time-dependency should be considered when nanomaterial dispersion protocols for ecotoxicity testing are developed

Study on Potential of Occupational Exposure Limits Harmonization in ASEAN-5 Countries

Five countries within the Association of South East Asian Nation (ASEAN-5), which consists of Indonesia, Malaysia, Singapore, Thailand, and Philippines, use a variety of chemicals in their industries and set Occupational Exposure Limit (OEL) as a regulation or reference instrument to control chemical. This study is aimed to assess the potential of OEL harmonization amongst ASEAN-5 since there is extensive labor exchange between South East Asian Region. Seven OELs (three lists from Indonesia) were compared between each other; and also, with TLV ACGIH 2016 and PEL OSHA as references. The geometric similarity measure (GSM) and non-metric multidimensional scaling plots were used for OEL similarities evaluation. There were a total of 713chemical substances in the list being compared; 40 common substances that were available in all OEL lists; and 73 unique substances that appear only in 1 list of OEL. In non-metric multidimensional scaling plots, it was found that 5 OEL have close similarities with both TLV ACGIH 2016 and PEL OSHA. Thailand-OEL and Regulationof Ministry of Health of Indonesia No. 70 of Year 2016 showed dissimilarity with TLV ACGIH 2016 and PEL OSHA 2016 due to having lesser number of substances. There was a potential of OEL harmonization within ASEAN-5 since some similarities in listed substances and concentration limit were found. Keywords: chemical substances, harmonization study, occupational exposure limit, regulatio

Kajian Risiko Pajanan Sinar Gama dan Radon pada Pekerja di Area Terowongan Eksplorasi Uranium Remaja, Kalimantan Barat

Kajian risiko pajanan radiasi gama dan gas radon dilakukan di area terowongan eksplorasi uranium dalam upaya melindungi pekerja dari bahaya radiasi pengion di tempat kerja. Pengukuran pajanan sinar gama dan konsentrasi gas radon dilakukan di dalam terowongan eksplorasi uranium Remaja dan sekitar kamp pekerja di daerah Kalan, Kalimantan Barat. Pajanan sinar gama diukur menggunakan surveimeter gama, sementara pajanan radon (222Rn/220Rn) menggunakan detektor pasif RADUET. Konsentrasi gas radon dan toron di dalam terowongan secara umum cukup tinggi, berkisar antara 188,84 hingga 495,86 Bq/m3 (rata-rata 375,80 Bq/m3) sementara toron berkisar antara 58,07 hingga 340,73 Bq/m3 (rata-rata 189,80 Bq/m3). Nilai tersebut berada di atas reference level radon (300 Bq/m3) yang disaranakan oleh International Commission on Radiation Protection (ICRP). Dosis efektif tahunan sinar gama mencapai nilai 147,88 mSv di dalam terowongan eksplorasi. Nilai tersebut berada di atas nilai batas dosis untuk pekerja, yaitu 20 mSv. Pengendalian pajanan sangat penting dilakukan dengan memenuhi prinsip “as low as reasonably achievable” (ALARA) dan proteksi radiasi eksterna untuk melindungi pekerja di dalam terowongan dari masalah kesehatan yang disebabkan oleh pajanan dari sinar gama, radon, dan toron

GIS-based mapping of noise from mechanized minerals ore processing industry

Monitoring workers’ exposure to occupational noise is essential, especially in industrial areas, to protect their health. Therefore, it is necessary to collect information on noise emitted by machines in industries. This research aims to map the noise from mechanized mineral ore industry using the kriging interpolation method, and ArcGIS 10.5.1 to spatially process and analyze data. The experimental calculation result of the semivariogram showed a 0.83 range value, with an essential parameter of 1.75 sill and a spherical total theoretical model. The result shows that the main machines with the highest power consumption and the Leq value are located in the southwest position of the sampled areas with a noise map-projected to assess the workers’ noise exposure level. In conclusion, the study found that the highest noise level was generated ranged from 88 to 97 dBA and contributed to the whole sound pressure level at certain positions