Report: Inhalation of ​Nanomaterials Causes “Most Significant” Health Effects
A summary report published in December by the Danish Environmental Protection Agency (EPA) states that inhalation of nanomaterials is the exposure route that provides the most significant health effects to consumers and others. The report, “Better Control of Nanomaterials,” discusses the overall results of the Danish government’s four-year initiative to better understand the pathways of exposure to nanomaterials and the potential risks to consumers and the environment. The initiative comprises 30 separate projects that assessed nanosilver in textiles; the fate of nanomaterials in the environment; dermal, oral, inhalation, and eye exposures to nanomaterials; titanium dioxide in consumer products; release of nanomaterials from ink and toner cartridges for printers; and several other related topics. The initiative also includes the establishment of a register of products containing nanomaterials. Potential risks from several products and scenarios were assessed as part of the initiative. Failure to use respiratory protective equipment during the application of nanomaterial-containing paint with a spray gun is one example of how consumers may be exposed. Another scenario that presents a likely risk of inhalation exposure is sanding surfaces treated with water-based primer that contains nano-titanium dioxide. Possible risks of inhalation exposure exist for products such as face powder containing nano-silica, disinfectant sprays containing nano-silver, and cement containing nano-TiO2. Nanomaterial-containing sunscreen pump spray and dental fillings present “uncertain” risks, according to the Danish EPA, which cautions that many of its findings are based on conservative, worst-case assumptions given the general scarcity of available information on the health effects of exposure to nanomaterials.
Although the focus of the report is on exposures to consumers and the environment, it notes that the highest ​risk of inhalation of nanomaterials exists in the working environment.
Some aerosol paint sprays that do not contain nanoparticles result in the formation of nano-structures on painted surfaces, according to the summary report, which may present health risks. However, spray products in general present some health risks, and the project on assessment of aerosol sprays was unable to determine whether products containing nanoparticles present a greater risk. Uncertain risks were associated with oral exposure from chewing gum containing nano-TiO2 and from consuming food additives containing nano-silica. Oral exposures to sunscreen lotion, sunscreen pump spray, and sunscreen lipstick presented possible risks to consumers, but the report notes that risks related to dermal exposure “apparently are not significant, which is in accordance with the existing knowledge indicating that nanomaterials are not absorbed through the skin and do not, to a substantial degree, lead to damages of the skin.” In addition, eye exposure does not seem to present substantial risk to consumers.
Although the focus of the report is on exposures to consumers and the environment, it notes that the highest risk of inhalation of nanomaterials exists in the working environme​nt, where workers produce products containing nanomaterials and must contend with waste management related to production.
Though workers’ exposures may be larger than consumers’ and may extend through their entire working lives, the report also mentions that nanomaterials are typically used in the working environment with ventilation, personal protective equipment, and other protective measures that are not always used in consumer settings. The full report has been translated into English and is available as a PDF on the Danish EPA’s website.