What are the risks for exposed workers?

What are the risks for exposed workers?

By AVICENN Team – Last Modified May 2022

New properties, new risks?

At the nanoscale, materials can exhibit enhanced or new properties some of which may be dangerous for exposed workers (higher reactivity, explosiveness, flammability, etc.).

Among them, the potentials of emission and occupational exposure to aerosols during operations involving nanomaterials have been considered as one of the main emerging risks in the workplace since at least 2009 by EU-OSHA.¹See Workplace Exposure to Nanomaterials, EU-OSHA, European Agency for Safety and Health at Work, 2009. 

Risks still poorly understood

The repercussions that exposure to manufactured nanomaterials can have on human health are still largely unknown and marred by uncertainty.

Knowledge relating more specifically to the effects on the health of workers is even more limited.

Rare and limited toxicological studies

The rarity and limits of toxicological studies do not allow us to foresee simple and unequivocal answers on the risks of nanomaterials in the short term. Until recently, in particular, few studies focused on the inhalation of nanomaterials, even though this is the most likely occupational exposure route and the most worrying for exposed workers.²See our sheet on entry points & the future of nanomaterials in the human body. This path is however more taken into account now. Nevertheless, the harmful effects observed in numerous toxicological studies are often disputed or minimized by manufacturers who hide behind the expectation of convincing results from epidemiological studies… in order to play the clock.

Exposure difficult to measure 

Despite the development of more efficient instruments (in terms of sensitivity, reproducibility, flexibility) and the improvement of knowledge³See in particular INRS work on nanomaterials, measurements at workstations are not carried out in a systematic and simple manner. This requires high-performance equipment that is often complex to implement, expensive, combining several techniques as well as technical skills that are still rare.

Epidemiology studies rarely of good quality

Effects that can take years to appear

Health effects on workers may take many years to appear, after a period of repeated exposure and a relatively long lag time between the end of exposure and the date of onset of symptoms or discovery of disease⁴“Chronic effects – such as lung and circulatory infections – can take decades to manifest and be diagnosed” – Aída Maria Ponce Del Castillo (ETUI), Nanomaterials in the workplace, what are the challenges for worker health?May 2013. These conditions do not necessarily have a specific character, there is therefore nothing to distinguish them from another origin, in particular extra-occupational. 

Difficult to establish a clear causal link between professional exposure to nanos and pathologies

The causal link is all the more difficult to determine since workers are often exposed to multiple chemical substances:

• in their workplace, with interactions between nanos and "classic" and sometimes dangerous chemical substances that are difficult to identify and control (we then speak of“cocktail effect”).
• in everyday life, via non-occupational exposure to nanos and chemical substances suffered by the general population as a whole via thefood,water, cosmetics, air pollution, etc.

In the meantime, due to a lack of indisputable toxicological, epidemiological and biomedical data, raw materials in nanometric form continue to be handled by workers without prior information. The French authorities have, however, acknowledged that "Efforts must be continued to improve knowledge and allow, in particular, to refine the assessment of effects and risks"⁵Response of the French authorities to the public consultation "Towards a strategic nanotechnology action plan (SNAP) 2010-2015"March 2010. Work on the risks associated with occupational exposure to nanos is carried out within platforms specializing in nano risks at INERIS, INRS and CEA. 

However, worrying signals

Although incomplete, the data we have are rather worrying: inhaled nanomaterials can in fact diffuse in the body, transform from a physico-chemical point of view, then accumulate in certain organs, in the blood and inside the cells⁶See our sheet on entry points and the future of nanos in the human body  and cause disturbances or even negative effects (pulmonary inflammatory reaction; pulmonary fibrosis; risk of lung cancer in case of inhalation of titanium dioxide nanoparticles and carbon nanotubes long and rigid for example).

As early as 2014, the French National Agency for Health Security (ANSES) had recommended the classification of nanomaterials as dangerous substances within the framework of the European CLP regulations.⁷Assessment of the risks associated with nanomaterials – Issues and update of knowledge, ANSES, April 2014 (online May 15, 2014).

The risk of fire and explosion is also particularly worrying (especially for aluminum, magnesium or lithium nanoparticles as well as for carbon nanotubes)⁸See in particular:
- Nanomaterials in transport and housing: What are the risks associated with thermal degradation?, Simon Delcour, LNE, webinar, June 2019
- Army scientists have a blast with aluminum nanoparticles, US Army Research Laboratory, June 7, 2018.  

What similarities with asbestos?  

In animals, effects similar to those of asbestos have been observed: laboratory rats have developed mesothelioma following exposure to certain types of carbon nanotubes. The toxicity of carbon nanotubes has been clarified by many works, not all of them have the same potential for danger. The longer and thinner they are, the more dangerous they are.⁹See our sheet on the risks of carbon nanotubes. As in the case of asbestos, we fear the consequences of a lack of prevention because the health effects are only likely to appear several years – even decades – after exposure to nanomaterials… hence the need of protect workers and set up a device monitoring their health over the long term.

Various cases of pathologies already reported 

Several cases of pathologies observed in workers exposed to nanoparticles have nevertheless already been reported:

Note, at the end of 2017, a legal "first" in Europe on occupational exposure to nanoparticles: a Spanish judge considered that a worker who had undergone a kidney transplant should not be assigned to a position exposing to nanomaterials¹⁴Integral prevention, Primera sentencia en Europa on exposure to nanoparticles, December 15, 2017 (Una juez de Pamplona decides, in an admirable sentence, that a trasplantado de riñón is especially sensitive to nanoparticles). This advice could have significant repercussions in the years to come.

What vigilance?

Too limited protection for workers exposed to nanomaterials

About ten years ago, companies, in France and abroad, were very little able to protect the health and safety of their workers in relation to nano risks.¹⁵See in particular:
– CD Engeman et al., Governance implications of nanomaterials companies' inconsistent risk perceptions and safety practices, Journal of Nanoparticle Research, 14 (3), 1-12, February 2012
– INRS, Identification of employees potentially exposed to nanoparticles, Occupational Health References, n°132, December 2012
– Conti JA et al. Health and safety practices in the nanomaterials workplace: results from an international survey, Environmental Science & Technology, 42 (9), 3155-3162, 2008. The situation is slowly improving: personal protective equipment (PPE) and collective protective equipment are gradually being put in place, particularly for staff in research and development laboratories. These issues of safety of use and health risks are beginning to be taken into account more, but there is still much to do: efforts must be intensified.

Companies reluctant to participate in risk research efforts

In April 2019, INRS launched a first call to companies using amorphous silicas for occupational health research: "Occupational exposure to nanostructured amorphous silicas: biomarkers of early effects" (2019-2022). In the absence of a sufficient number of responses, INRS had to launch a new call two and a half years later, in September 2021… Will it have made it possible to recruit more companies? It is by the yardstick of this type of approach that the gap between the display and the reality of the concept of corporate social responsibility (CSR) can be measured...

Too few practical and directly applicable recommendations

Apart from publications by INRS, the High Council for Public Health (HCSP) or the European Agency for Safety and Health at Work (EU OSHA)¹⁶See our “Nano and Occupational Health” bibliography, few operational recommendations are available to these professionals: so far, no course of action, recommendations from the French National Authority for Health (HAS) or learned societies have been published. 

Occupational health professionals working in companies ask themselves many questions: where are the nanos? how to identify hazards? how to evaluate exposures? what medical follow-up should be carried out? etc Their conclusion is unanimous: intervening and advising are complicated; there is a general lack of knowledge of the risks associated with nanos. These professionals emphasize being isolated in the field, lacking information, having few partners. However, this should not lead to inaction.

Since 2016, many of these occupational health professionals (occupational doctors, nurses, technicians or prevention advisers) have joined working groups on the identification and prevention of risks related to nanomaterials, set up within the framework of regional occupational health plans (PRST).
Tools to guide action have been established and distributed in the regions Bourgogne Franche Comté. as Pays de la Loire. as Auvergne Rhône Alpes and New Aquitaine. In New Aquitaine companies, a network of "nano referents" has been set up in the occupational health services of the 12 departments of this large region, with 4 priority areas: traceability of exposure, information and training on risks, advice on reducing exposure to a minimum, medical supervision and health monitoring.

The trade unions, especially the CFDT, organize awareness/training sessions on nano risks, in conjunction with INRS and AVICENN.

A necessity: intensify efforts!

All these elements together lead to advocating the greatest vigilance, the precautionary principle obliges. The stakes are high: it is neither more nor less thanavoid repeating past mistakes : if the carcinogenic effects of asbestos were demonstrated in the 1930s, it was not until the 1990s that the first prohibition laws came into force...