Exposure Limits for Nanoparticles: Report of an International Workshop on Nano Reference Values

Broekhuizen, Pieter van; Veelen, Wim Van; Streekstra, Willem-Henk; Schulte, Paul A.; Reijnders, L.

doi:10.1093/annhyg/mes043

Cited by 47 publications

(35 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, exposure limits have yet to be set for any type of NP due to limited studies on which to base such limits (van Broekhuizen et al, 2012). The permissible exposure limit for Cd as set by OSHA (2012) is a time-weighted average of 5 μg/m 3 with an action level of 2.5 μg/m 3 over the course of an eight-hour work shift, which can result in exposure levels of up to 20 μg per day.…”

Section: Discussionmentioning

confidence: 99%

Short-term inhalation of cadmium oxide nanoparticles alters pulmonary dynamics associated with lung injury, inflammation, and repair in a mouse model

Blum

Rosenblum

Grünig

et al. 2014

Inhalation Toxicology

View full text Add to dashboard Cite

Context Cadmium oxide nanoparticles (CdO NPs) are employed in optoelectronic devices and as a starting material for generating quantum dots as well as for medical imaging and targeting of pharmaceutical agents to disease sites. However, there are lack of data concerning short- and long-term effects of CdO NPs on the lungs. Objective To determine the effects of inhaled CdO NPs at an occupationally relevant concentration on pulmonary injury and repair, and on systemic immunity in adult male mice Methods Mice were exposed to 240 μg CdO NPs/m3 for seven days (3 h/d) and lavage levels of pulmonary injury/inflammatory markers, bacterial uptake by circulating phagocytes, and lung histology examined either one or seven days following the final exposure. Results Levels of total protein, lactate dehydrogenase activity, cytokine markers of inflammation (i.e. interleukin-1β, tumor necrosis factor-α, and interferon-γ), tissue remodeling matrix metalloproteinases (MMP)-2 and -9 activity, and phagocytic activity of circulating phagocytes were significantly increased one day after the final exposure. By seven days post-exposure, MMP-2 activity decreased to control levels, while MMP-9 activity remained significantly above control values, although dropping by about half from day one. Conclusions This study demonstrates that short-term inhalation exposure to CdO NPs can stimulate pathways in the lungs associated with inflammation, cell injury, and tissue remodeling as well as alter immune function. Findings here demonstrate that even short-term inhalation exposure to CdO NPs in the workplace could lead to deleterious pulmonary effects in exposed workers.

show abstract

Section: Discussionmentioning

confidence: 99%

Short-term inhalation of cadmium oxide nanoparticles alters pulmonary dynamics associated with lung injury, inflammation, and repair in a mouse model

Blum

Rosenblum

Grünig

et al. 2014

Inhalation Toxicology

View full text Add to dashboard Cite

show abstract

“…However, one must interpret the results cautiously as direct reading instruments respond to all aerosols regardless of their source; the instrument response may not be solely due to process generated aerosols. (4, 6, 50) …”

Section: Discussionmentioning

confidence: 99%

“…Aerosol concentrations measured before and after these tasks are used to estimate in-plant local background concentrations that are a combination of ambient air pollution and emissions from other in-plant operations that can contribute to the overall measurement. (6) Local background concentrations were measured to assess the contribution from the process under study versus incidental and other process contaminants.…”

Section: Methodsmentioning

confidence: 99%

“…(10) There have also been suggestions for lower, provisional occupational exposure limits as compared to bulk (or parent) materials. (5, 6, 11) As a result, decisions concerning engineering controls and personal protective equipment (PPE) need to be made by referring to the relevant exposure limits (if available) or exposure goals based on supplier recommendations or manufacturers’ exposure goals.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Exposure Controls for Nanomaterials at Three Manufacturing Sites

Heitbrink¹,

Lo²,

Dunn³

2014

Journal of Occupational and Environmental Hygiene

View full text Add to dashboard Cite

Because nanomaterials are thought to be more biologically active than their larger parent compounds, careful control of exposures to nanomaterials is recommended. Field studies were conducted at three sites to develop information about the effectiveness of control measures including process changes, a downflow room, a ventilated enclosure, and an enclosed reactor. Aerosol mass and number concentrations were measured during specific operations with a photometer and an electrical mobility particle sizer to provide concentration measurements across a broad range of sizes (from 5.6 nm to 30 μm). At site A, the dust exposure and during product harvesting was eliminated by implementing a wait time of 30 minutes following process completion. And, the dust exposure attributed to process tank cleaning was reduced from 0.7 to 0.2 mg/m3 by operating the available process ventilation during this task. At site B, a ventilated enclosure was used to control dust generated by the manual weigh-out and manipulation of powdered nanomaterials inside of a downflow room. Dust exposures were at room background (under 0.04 mg/m3 and 500 particles/cm3) during these tasks however, manipulations conducted outside of the enclosure were correlated with a transient increase in concentration measured at the source. At site C, a digitally controlled reactor was used to produce aligned carbon nanotubes. This reactor was a closed system and the ventilation functioned as a redundant control measure. Process emissions were well controlled by this system with the exception of increased concentrations measured during the unloading the product. However, this emission source could be easily controlled through increasing cabinet ventilation. The identification and adoption of effective control technologies is an important first step in reducing the risk associated with worker exposure to engineered nanoparticles. Properly designing and evaluating the effectiveness of these controls is a key component in a comprehensive health and safety program.

show abstract

“…There are provisional exposure limit values for ENMs, called nano reference values (NRVs), which are designed to provide warning concentration levels for ENMs, to judge when exposure control measures should be taken [64,65]. The NRVs are designed for ENM particles in the range of 1–100 nm and thus cannot be utilized here, because the NDs had agglomerated into particles approximately over 500 nm.…”

Section: Discussionmentioning

confidence: 99%

Range-Finding Risk Assessment of Inhalation Exposure to Nanodiamonds in a Laboratory Environment

Koivisto

Palomäki

Viitanen

et al. 2014

IJERPH

View full text Add to dashboard Cite

This study considers fundamental methods in occupational risk assessment of exposure to airborne engineered nanomaterials. We discuss characterization of particle emissions, exposure assessment, hazard assessment with in vitro studies, and risk range characterization using calculated inhaled doses and dose-response translated to humans from in vitro studies. Here, the methods were utilized to assess workers’ risk range of inhalation exposure to nanodiamonds (NDs) during handling and sieving of ND powder. NDs were agglomerated to over 500 nm particles, and mean exposure levels of different work tasks varied from 0.24 to 4.96 µg·m−3 (0.08 to 0.74 cm−3). In vitro-experiments suggested that ND exposure may cause a risk for activation of inflammatory cascade. However, risk range characterization based on in vitro dose-response was not performed because accurate assessment of delivered (settled) dose on the cells was not possible. Comparison of ND exposure with common pollutants revealed that ND exposure was below 5 μg·m−3, which is one of the proposed exposure limits for diesel particulate matter, and the workers’ calculated dose of NDs during the measurement day was 74 ng which corresponded to 0.02% of the modeled daily (24 h) dose of submicrometer urban air particles.

show abstract

Exposure Limits for Nanoparticles: Report of an International Workshop on Nano Reference Values

Cited by 47 publications

References 16 publications

Short-term inhalation of cadmium oxide nanoparticles alters pulmonary dynamics associated with lung injury, inflammation, and repair in a mouse model

Short-term inhalation of cadmium oxide nanoparticles alters pulmonary dynamics associated with lung injury, inflammation, and repair in a mouse model

Exposure Controls for Nanomaterials at Three Manufacturing Sites

Range-Finding Risk Assessment of Inhalation Exposure to Nanodiamonds in a Laboratory Environment

Contact Info

Product

Resources

About