While the rate of commercialisation of products containing nanomaterials accelerates rapidly, the environmental, health and safety studies that should have been done before commercial release occurs are only slowly appearing.
Two recent studies demonstrate how little we know about the potential risks associated with nanomaterials and how poorly our regulators are managing those risks.
A recent US study looked at the extent of exposure and inhalation of airborne nanoparticles in indoor environments. The study found that approximately 10% of consumer products that contain nanomaterials may become airborne and be inhaled, and that the health risks associated with this exposure are not known. This exposure can occur at various stages in the lifecycle of products.
The study’s analysis of exposure levels was based on estimates of the number of products containing nanomaterials using the database compiled by the Project on Emerging Technologies. Based on two years’ data from the mandatory French nanomaterial register, these figures are almost certainly too low – meaning levels of exposure to nanomaterials in aerosol form are likely to be much greater than those estimated in this study.
The study makes a number of recommendations, focusing both on the need for additional research and data and “the clear need for nanomaterial reporting and labelling in consumer products.” These steps are critical for proper risk assessments and the tracking of both the human health and environmental impacts of these materials.
Another recent study looked how effective waste treatment is at removing nano titanium dioxide (TiO2). study found that “under realistic water chemistries there is a possibility for significant release” of nano TiO2. When the nano TiO2 was coated (which it quite often is) and natural organic matter was present – which is a pretty realistic scenario – around 20% of the nano TiO2 remained in the treated water. This is important because effluent from wastewater facilities is either discharged into the environment or added to drinking water supplies. It is estimated that global emissions to water bodies of nano TiO2 via wastewater treatment plants are between 1100 and 29,200 metric tons per year.
There is significant concern regarding the potential health and environmental risks associated with nano TiO2. Some studies have found adverse human health effects and it is well documented that nano TiO2 is toxic to a number of aquatic organisms. It has been found to react with sunlight to produce free radicals that destroy living matter.
Even in the best case scenarios investigated in the study, approximately 5 parts per million of the smaller nano TiO2 aggregates stayed suspended in solution. The study notes that these are “the particles that are of greater health and environmental concern due to their increased reactivity and possible transport through the environment.”
Even the nano TiO2 that is removed from wastewater may still cause harm to the environment – since biosolids extracted from waste water are commonly applied to public and agricultural lands. Evidence is already emerging that nanomaterials may have significant impacts on soil and plant health.
Friends of the Earth is calling for:
- A nano-register to allow the tracking of nanomaterials through the supply chain and risk assessments to be conducted;
- A moratorium on the commercial release of products containing nanomaterials until testing has determined that they are safe;
- The labelling of all products containing nanomaterials to allow consumer choice.