Focused actions to protect carbon nanotube workers

Abstract

There is still uncertainty about the potential health hazards of carbon nanotubes (CNTs) particularly involving carcinogenicity. However, the evidence is growing that some types of CNTs and nanofibers may have carcinogenic properties. The critical question is that while the carcinogenic potential of CNTs is being further investigated, what steps should be taken to protect workers who face exposure to CNTs, current and future, if CNTs are ultimately found to be carcinogenic? This paper addresses five areas to help focus action to protect workers: (i) review of the current evidence on the carcinogenic potential of CNTs; (ii) role of physical and chemical properties related to cancer development; (iii) CNT doses associated with genotoxicity in vitro and in vivo; (iv) workplace exposures to CNT; and (v) specific risk management actions needed to protect workers.

Malignant pleural mesothelioma: history, controversy and future of a manmade epidemic

“…Surveillance programmes should be extended worldwide, manufacturers in North America being focused more on SWCNTs, and Asia and Europe (mostly Japan followed by China) leading the production of MWCNTs [166]. Exposure control challenges should involve both the evaluation of exposure control techniques, and the management of populations at risk through the identification of work practice recommendations and secondary prevention measures [167,168]. Due to the probable latency, follow-up analysis should be performed on CNT-exposed people.…”

Carbon nanotubes: Properties, biomedical applications, advantages and risks in patients and occupationally-exposed workers

“…14 Workers are involved with CNTs throughout the nanomaterial lifecycle, from research in laboratories, through start-up efforts, manufacture, incorporation of CNTs into products, manipulating CNT containing products, and finally through disposal and recycling of CNTs. 1,15 Proposed occupational air exposure limits (OELs) for specific types of CNTs have ranged in literature from approximately 2 to 50 mg/m 3 based on the estimated risk of non-cancerous adverse lung effects (inflammation and fibrosis). 15 The main work practice recommendations described are: containing tasks in processes that could result in the release of airborne CNTs in the workplace; handling of CNT as slurries rather than dry powders where possible; and dispensing, weighing, or sonication processes should be performed on well-designed ventilated benches or in effective ventilated exposures, performing initial and periodic area and personal exposure monitoring.…”

“…1,15 Proposed occupational air exposure limits (OELs) for specific types of CNTs have ranged in literature from approximately 2 to 50 mg/m 3 based on the estimated risk of non-cancerous adverse lung effects (inflammation and fibrosis). 15 The main work practice recommendations described are: containing tasks in processes that could result in the release of airborne CNTs in the workplace; handling of CNT as slurries rather than dry powders where possible; and dispensing, weighing, or sonication processes should be performed on well-designed ventilated benches or in effective ventilated exposures, performing initial and periodic area and personal exposure monitoring. 15 Medical surveillance of workers involved with CNTs must include initial and periodic evaluations of the respiratory system and exposure registries should be developed for all workers with potential exposure to CNTs.…”

“…15 Medical surveillance of workers involved with CNTs must include initial and periodic evaluations of the respiratory system and exposure registries should be developed for all workers with potential exposure to CNTs. 15 …”

A Road Map Toward a Globally Harmonized Approach for Occupational Health Surveillance and Epidemiology in Nanomaterial Workers

“…Other relevant mechanisms via which nanomaterials are believed to cause effects are particles acting as transport vehicles, [37][38][39] leading to the generation of toxic substances such as free radicals and oxidative stress, [40][41][42] and by the fiber paradigm, according to which long nanotubes are believed to act similar to long asbestos fibers. 32,[43][44][45] There is already a wealth of information in the epidemiological literature about exposure to "traditional" or "classic" particles and other (nonengineered) materials that fall within the European Commission's definition of nanomaterials. These workplace fibers, traditional nanomaterials, and environmental airborne particulate matter indicate the types of effects that should be considered, although as yet unknown effects should not be excluded.…”