A study commissioned by the EU Observatory for Nanomaterials has found a lack of data on female fertility. Studies on reproductive performance were also scarce. As such, the study calls for more coordinated tests and follow up of outcomes when concerns are identified.
This lack of data results in uncertainties on the potential toxic effects of nanomaterials over multiple generations.
The available information identified a concern for developmental toxicity for the materials that were tested and indicates that nanomaterials may be able to cross the placental barrier and reach developing foetuses, as well as affect critical organ systems.
The report also identifies a lack of studies comparing bulk and nanoforms of the same substance, resulting in uncertainties in possible differences in toxicity.
Reproductive and developmental toxic effects can occur after repeatedly being exposed to a substance. There is concern that nanomaterials may cause these effects due to their ability to pass cell membranes and biological barriers in our bodies.
The study makes several recommendations for testing such as following OECD test guideline principles as much as possible, even when full study guidelines cannot be applied.
Screening was carried out for 2 152 publications, out of which 111 relevant studies covering 19 nanomaterials and using mainly in vivo testing were reviewed in more detail.
Nano titanium dioxide and nano silver were the most frequently tested materials and were used in 48 % of the reviewed studies. Both have widespread uses, for example, nano titanium dioxide is used in sunscreens to absorb UV light and nano silver is used in many textiles such as pillowcases and plush toys for its antimicrobial properties.
Nano-sized particles of zinc oxide, silicon oxide and carbon-based nanomaterials contributed to 34 % of the studies, while the remaining 18 % focused on 13 different nanomaterials.
The study was carried out for the EUON by DHI A/S and the Danish National Research Centre for the Working Environment.
EUON aims to increase the transparency of information available to the public on the safety and markets of nanomaterials in the EU. A key aim of the observatory is to create a one-stop shop for information, where EU citizens and stakeholders including NGOs, industry, and regulators can find accessible and relevant safety information on nanomaterials on the EU market. The EUON uses a part of its funding to carry out studies on different aspects related to the safety and uses of nanomaterials on the EU market.