Tag Archives: manufactured nanomaterials

European Commission has issued evaluation of nanomaterial risk frameworks and tools

Despite complaints that there should have been more, there has been some research into risks where nanomaterials are concerned. While additional research would be welcome, it’s perhaps more imperative that standardized testing and risk frameworks are developed so, for example, carbon nanotube safety research in Japan can be compared with the similar research in the Netherlands, the US, and elsewhere. This March 15, 2017 news item on Nanowerk features some research analyzing risk assessment frameworks and tools in Europe,

A recent study has evaluated frameworks and tools used in Europe to assess the potential health and environmental risks of manufactured nanomaterials. The study identifies a trend towards tools that provide protocols for conducting experiments, which enable more flexible and efficient hazard testing. Among its conclusions, however, it notes that no existing frameworks meet all the study’s evaluation criteria and calls for a new, more comprehensive framework.

A March 9, 2017 news alert in the European Commission’s Science for Environment Policy series, which originated the news item, provides more detail (Note: Links have been removed),

Nanotechnology is identified as a key emerging technology in the EU’s growth strategy, Europe 2020. It has great potential to contribute to innovation and economic growth and many of its applications have already received large investments. However,there are some uncertainties surrounding the environmental, health and safety risks of manufactured nanomaterials. For effective regulation, careful scientific analysis of their potential impacts is needed, as conducted through risk assessment exercises.

This study, conducted under the EU-funded MARINA project1, reviewed existing frameworks and tools for risk assessing manufactured nanomaterials. The researchers define a framework as a ‘conceptual paradigm’ of how a risk assessment should be conducted and understood, and give the REACH chemical safety assessment as an example. Tools are defined as implements used to carry out a specific task or function, such as experimental protocols, computer models or databases.

In all, 12 frameworks and 48 tools were evaluated. These were identified from other studies and projects. The frameworks were assessed against eight criteria which represent different strengths, such as whether they consider properties specific to nanomaterials, whether they consider the entire life cycle of a nanomaterial and whether they include careful planning and prioritise objectives before the risk assessment is conducted.

The tools were assessed against seven criteria, such as ease of use, whether they provide quantitative information and if they clearly communicate uncertainty in their results. The researchers defined the criteria for both frameworks and tools by reviewing other studies and by interviewing staff at organisations who develop tools.

The evaluation was thus able to produce a list of strengths and areas for improvement for the frameworks and tools, based on whether they meet each of the criteria. Among its many findings, the evaluation showed that most of the frameworks stress that ‘problem formulation’, which sets the goals and scope of an assessment during the planning process, is essential to avoid unnecessary testing. In addition, most frameworks consider routes of exposure in the initial stages of assessment, which is beneficial as it can exclude irrelevant exposure routes and avoid unnecessary tests.

However, none of the frameworks met all eight of the criteria. The study therefore recommends that a new, comprehensive framework is developed that meets all criteria. Such a framework is needed to inform regulation, the researchers say, and should integrate human health and environmental factors, and cover all stages of the life cycle of a product containing nanomaterials.

The evaluation of the tools suggested that many of them are designed to screen risks, and not necessarily to support regulatory risk assessment. However, their strengths include a growing trend in quantitative models, which can assess uncertainty; for example, one tool analysed can identify uncertainties in its results that are due to gaps in knowledge about a material’s origin, characteristics and use.

The researchers also identified a growing trend in tools that provide protocols for experiments, such as identifying materials and test hazards, which are reproducible across laboratories. These tools could lead to a shift from expensive case-by-case testing for risk assessment of manufactured nanomaterials towards a more efficient process based on groupings of nanomaterials; and ‘read-across’ methods, where the properties of one material can be inferred without testing, based on the known properties of a similar material. The researchers do note, however, that although read-across methods are well established for chemical substances, they are still being developed for nanomaterials. To improve nanomaterial read-across methods, they suggest that more data are needed on the links between nanomaterials’ specific properties and their biological effects.

That’s all, folks.

OECD (Organization for Economic Cooperation and Development) and six years of nanomaterials safety work

Thank to Carla Caprioli (@carlacap)for pointing out this OCED (Organization for Economic Cooperation and Development overview document of their health and safety activities regarding nanomaterials, which was announced on Sept. 13, 2012 according SafeNano,

The Organisation for Economic Co-operation and Development Working Party on Manufactured Nanomaterials (OECD WPMN) has released an announcement regarding “Six Years of OECD Work on the Safety of Manufactured Nanomaterials: Achievements and Future Opportunities“.

As nanomaterials started to be used in commercial applications, OECD launched a programme of work in 2006 to ensure that the approaches for hazard, exposure and risk assessment for manufactured nanomaterials are of a high quality, science-based and internationally harmonised.

Based on this, the OECD and its member countries have come to the conclusion that the approaches for the testing and assessment of traditional chemicals are in general appropriate for assessing the safety of nanomaterials, but may have to be adapted to the specificities of nanomaterials. As with other chemicals, it is clear that each nanomaterial may pose specific challenges, but in most instances, they can be addressed with existing test methods and assessment approaches. In some cases, it might be necessary to adapt methods of sample preparation and dosimetry for safety testing. Similarly, adaptations may be needed for certain Test Guidelines but it will not be necessary to develop completely new approaches for nanomaterials. OECD continues to review all existing methodologies to identify and implement the necessary changes needed for their application to nanomaterials.

The four-page document won’t provide any new information or insights for long time observers but for new observers it does offer a listing of the OECD-published documents on safety and engineered nanomaterials. This excerpt from p. 4 of the document describes the OECD’s future plans,

There is still much to learn before our understanding of the safely [sic] use of manufactured nanomaterials is sufficient. However, the work achieved so far allows a better understanding of remaining “unknowns”. Knowing that the general approaches for the testing and assessment of traditional chemicals are in general appropriate for assessing the safety of nanomaterials, OECD will now focus on those specific aspects of manufactured nanomaterials, which require the adaptation and/or development of specific testing methods used for assessing human health and environmental safety as well as on developing guidance documents for assessing manufactured nanomaterials adapted to their specifities. This will  include guidance on estimating exposure (including fate and transport) on how to use results on physicochemicals [sic] endpoints in exposure assessment and mitigation measures to reduce exposure to safe levels (defining appropriate exposure metrics). At the same time, as R&D on manufactured nanomaterials/nanotechnologies is increasing, OECD remains vigilant in order to address emerging issues in a timely and resource efficient way.

It’s a good to find compilations either to point you in the right direction for your document or to confirm that you’ve found everything on the subject and on very rare occasions you may realize you found something everyone else missed.

Soybeans and nanoparticles

They seem ubiquitous today but there was a time when hardly anyone living in Canada  knew much about soybeans.  There’s a good essay about soybeans and their cultivation in Canada by Erik Dorff for Statistics Canada, from Dorff’s soybean essay,

Until the mid-1970s, soybeans were restricted by climate primarily to southern Ontario. Intensive breeding programs have since opened up more widespread growing possibilities across Canada for this incredibly versatile crop: The 1.2 million hectares of soybeans reported on the Census of Agriculture in 2006 marked a near eightfold increase in area since 1976, the year the ground-breaking varieties that perform well in Canada’s shorter growing season were introduced.

Soybeans have earned their popularity, with the high-protein, high-oil beans finding use as food for human consumption, animal rations and edible oils as well as many industrial products. Moreover, soybeans, like all legumes, are able to “fix” the nitrogen the plants need from the air. This process of nitrogen fixation is a result of a symbiotic interaction between bacteria microbes that colonize the roots of the soy plant and are fed by the plant. In return, the microbes take nitrogen from the air and convert it into a form the plant can use to grow.

This means legumes require little in the way of purchased nitrogen fertilizers produced from expensive natural gas-a valuable property indeed.

Until reading Dorff’s essay, I hadn’t early soybeans had been introduced to the Canadian agricultural sector,

While soybeans arrived in Canada in the mid 1800s-with growing trials recorded in 1893 at the Ontario Agricultural College-they didn’t become a commercial oilseed crop in Canada until a crushing plant was built in southern Ontario in the 1920s, about the same time that the Department of Agriculture (now Agriculture and Agri-Food Canada) began evaluating soybean varieties suited for the region. For years, soybeans were being grown in Canada but it wasn’t until the Second World War that Statistics Canada began to collect data showing the significance of the soybean crop, with 4,400 hectares being reported in 1941. In fact, one year later the area had jumped nearly fourfold, to 17,000 hectares…

As fascinating as I find this history, this bit about soybeans and their international importance explain why research about soyboans and nanoparticles is of wide interest (from Dorff’s essay),

The soybean’s valuable characteristics have propelled it into the agricultural mix in many parts of the world. In 2004, soybeans accounted for approximately 35% of the total harvested area worldwide of annual and perennial oil crops according to the Food and Agriculture Organization of the United Nations (FAO) but only four countries accounted for nearly 90% of the production with Canada in seventh place at 1.3% (Table 2). Soymeal-the solid, high-protein material remaining after the oil has been extracted during crushing-accounts for over 60% of world vegetable and animal meal production, while soybean oil accounts for 20% of global vegetable oil production.

There’s been a recent study on the impact of nanoparticles on soybeans at the University of California at Santa Barbara (UC Santa Barbara) according to an Aug. 20, 2012 posting by Alan on the Science Business website, (h/t to Cientifica),

Researchers from University of California in Santa Barbara found manufactured nanoparticles disposed after manufacturing or customer use can end up in agricultural soil and eventually affect soybean crops. Findings of the team that includes academic, government, and corporate researchers from elsewhere in California, Texas, Iowa, New York, and Korea appear online today in the Proceedings of the National Academy of Sciences.

The research aimed to discover potential environmental implications of new industries that produce nanomaterials. Soybeans were chosen as test crops because their prominence in American agriculture — it is the second largest crop in the U.S. and the fifth largest crop worldwide — and its vulnerability to manufactured nanomaterials. The soybeans tested in this study were grown in greenhouses.

The Aug. 20, 2012 UC Santa Barbara press release has additional detail abut why the research was undertaken,

“Our society has become more environmentally aware in the last few decades, and that results in our government and scientists asking questions about the safety of new types of chemical ingredients,” said senior author Patricia Holden, a professor with the Bren School [UC Santa Barbara’s Bren School of Environmental Science & Management]. “That’s reflected by this type of research.”

Soybean was chosen for the study due to its importance as a food crop –– it is the fifth largest crop in global agricultural production and second in the U.S. –– and because it is vulnerable to MNMs [manufactured nanomaterials]. The findings showed that crop yield and quality are affected by the addition of MNMs to the soil.

The scientists studied the effects of two common nanoparticles, zinc oxide and cerium oxide, on soybeans grown in soil in greenhouses. Zinc oxide is used in cosmetics, lotions, and sunscreens. Cerium oxide is used as an ingredient in catalytic converters to minimize carbon monoxide production, and in fuel to increase fuel combustion. Cerium can enter soil through the atmosphere when fuel additives are released with diesel fuel combustion.

The zinc oxide nanoparticles may dissolve, or they may remain as a particle, or re-form as a particle, as they are processed through wastewater treatment. At the final stage of wastewater treatment there is a solid material, called biosolids, which is applied to soils in many parts of the U.S. This solid material fertilizes the soil, returning nitrogen and phosphorus that are captured during wastewater treatment. This is also a point at which zinc oxide and cerium oxide can enter the soil.

The scientists noted that the EPA requires pretreatment programs to limit direct industrial metal discharge into publicly owned wastewater treatment plants. However, the research team conveyed that “MNMs –– while measurable in the wastewater treatment plant systems –– are neither monitored nor regulated, have a high affinity for activated sludge bacteria, and thus concentrate in biosolids.”

The authors pointed out that soybean crops are farmed with equipment powered by fossil fuels, and thus MNMs can also be deposited into the soil through exhaust.

The study showed that soybean plants grown in soil that contained zinc oxide bioaccumulated zinc; they absorbed it into the stems, leaves, and beans. Food quality was affected, although it may not be harmful to humans to eat the soybeans if the zinc is in the form of ions or salts, in the plants, according to Holden.

In the case of cerium oxide, the nanoparticles did not bioaccumulate, but plant growth was stunted. Changes occurred in the root nodules, where symbiotic bacteria normally accumulate and convert atmospheric nitrogen into ammonium, which fertilizes the plant. The changes in the root nodules indicate that greater use of synthetic fertilizers might be necessary with the buildup of MNMs in the soil.

At this point, the researchers don’t know how zinc oxide nanoparticles and cerium oxide nanoparticles currently used in consumer products and elsewhere are likely to affect agricultural lands. The only certainty is that these nanoparticles are used in consumer goods and, according to Holden, they are entering agricultural soil.

The citation for the article,

Soybean susceptibility to manufactured nanomaterials with evidence for food quality and soil fertility interruption by John H. Priester, Yuan Ge, Randall E. Mielke, Allison M. Horst Shelly Cole Moritz, Katherine Espinosa, Jeff Gelb, Sharon L. Walker, Roger M. Nisbet, Youn-Joo An, Joshua P. Schimel, Reid G. Palmer, Jose A. Hernandez-Viezcas, Lijuan Zhao, Jorge L. Gardea-Torresdey, Patricia A. Holden. Published online [Proceedings of the National Academy of Sciences {PNAS}] before print August 20, 2012, doi: 10.1073/pnas.1205431109

The article is open access and available here.