MICROPLASTICS AND NANOPLASTICS

Worldwide production of plastic has increased exponentially since the end of World War II, as has the volume of related waste, resulting in a ubiquitous global dispersal of plastic debris in the environment. Plastics are progressively fragmented by various weathering and biological processes, leading to the formation of microplastics (MPLs) and ultimately nanoplastics (NPLs). MPLs and NPLs are typically defined as polymer particles smaller than 5 mm and 1000 nm, respectively, although cut-off definitions in the literature differ. In addition, plastics in the MPL size range are intentionally manufactured as ingredients of consumer products like industrial abrasives, or microbeads in cosmetics, and can become fragmented into nanoplastics. Since plastic has low degradability and long-life in the environment, the continued accumulation of MPLs and NPLs in environmental compartments and their potential impacts on biota and human health has emerged as an urgent planetary problem. The European Commission’s SCHEER committee (SCHEER – Scientific Committee on Health, Environmental, and Emerging Risks, 2018) recently issued a statement listing MPLs and NPLs in the environment as one of 14 priority issues.

There is abundant literature reporting the presence of MPLs in aquatic and terrestrial ecosystems, as well as demonstrating their impacts on biota at individual and community level. Only very recently, MPLs and NPLs have also been detected in drinking water, urban ambient air, and a range of food items, including other than seafood. Thus, human populations are exposed to MPLs and NPLs in everyday life with unknown health effects. Smaller MPLs are known to be the most abundant size fraction in drinking water and the marine environment, but we still have only patchy evidence on their occurrence, and we have no such information whatsoever for NPLs. From a biological standpoint, smaller MPLs and NPLs are expected to be the most relevant fraction, as they are taken up by the respiratory or gastrointestinal epithelia, and may reach systemic circulation and organs.

The impact of MPL has been partly addressed by a few EU policies (REACH, Single Use Plastics and Fishing Gear, The Marine Strategy Framework Directive, and the EU Plastics Strategy). However, current knowledge on exposure and hazard is insufficient for a formal health risk assessment of MPLs and NPLs, and to regulate MPLs and NPLs in food, drinking water, air, and other media. Despite the exponentially growing number of scientific publications on MPLs, many uncertainties remain. A number of research needs have been identified by the European Food Safety Agency (EFSA), the Science Advise for Policy by European Academies (SAPEA), and the WHO, including the need to: develop and standardise analytical methods for MPLs, particularly for smaller sizes (<150 mm); understand the uptake, fate, and local effects of plastic particles in the gastrointestinal tract; improved and harmonised methods for assessing exposure, fate, and effects; understand the potential modes of toxicity of different MPL and NPL size and shape combinations using carefully selected human models.

To date, the health effects of exposure to MPLs/NPLs are largely unknown. Most of the few toxicological studies conducted so far have assessed much higher concentrations than those currently reported in the environment, particles that are not representative of those found in the real-world setting, or relatively short exposure times. Importantly, there have not yet been any human studies in real-life conditions. Only by providing robust evidence about the real-life exposure and risks for humans can we make cost-effective decisions and design legislative actions to eventually protect the population.

Our research is aimed to support hazard identification and human health risk assessment of MPLs and NPLs by generating data on exposure to these plastic particles, their early biological effects in human populations, and the underlying toxicological pathways.

NANOPARTICLES AND FOOD

Nanoscience is one of the most innovative disciplines with strong potentialities in many areas, including food science. The presence of nanomaterials (NMs) in everyday products is on an ever-growing trend. While nanoscale ingredients may offer potential benefits, their safety remains poorly understood, and a growing body of research is raising concerns about their use in the food industry. Many NMs are commonly available on the market (sunscreens, cosmetics, moisturizers, stain, moisture and odor repellent fabrics and clothing, etc). In particular, nano-hydroxyapatite (nano-HA), nano silicon dioxide (SiO2) and titanium dioxide (TiO2), are being used in several products ranging from food and beverage ingredients to packaging. Taking into consideration that babies’ bodies and immune system are developing and can be especially susceptible to exposures from hazardous NMs, there is a lack of specific toxicology studies for these vulnerable population sample. Our research group aims at providing new insights on the potential toxicity of NPs contained in baby formula by in vivo mice and ex vivo newborn studies, from the gene to the protein level.