Impact of plastic on food chain concerns

SYDNEY: They are often smaller than the diameter of a human hair and so tiny they are invisible to the eye, but the impact micro and nanoplastics have on our food safety could be huge, according to a new report.

Fresh concerns have been raised over the effect of these plastics on our food safety and security, in the report from Australia’s science agency CSIRO.

While earlier studies tracked plastics in fish, this research looks at microplastics from a food safety point of view.

The study concluded the micro and nanoplastics entered the food chain through numerous pathways and called for more research to establish how they could affect human health.

‘‘There is a lot of research to be done to better quantify the potential risk,’’ lead author and CSIRO researcher Dr Jordi Nelis said.

‘‘They may really have potential negative effects on food safety and food security.’’

The researcher said plastics were found all in types of food: including fish, meat, chicken, rice, water, takeaway food and even fresh produce.

One of the main ways they entered the human food chain was through food processing and packaging.

‘‘Fresh food, for example, can be plasticfree when it’s picked or caught but contain plastics by the time it’s been handled, packaged and makes its way to us.’’

The paper found agricultural systems were increasingly affected by micro and nanoplastics, raising concerns for global food safety and security.

Plastics are also entering the soil through biosolids used as fertiliser sourced from wastewater treatment, which can contain plastic particles from the washing of synthetic clothing.

‘‘There are clear indicators that microplastics can change soil structure, also that they may affect crop production,’’ Nelis said.

‘‘But we have no idea how many microplastics there are in the soil.’’

While the study did not look at how toxic microplastics can be to human health, it did find big knowledge gaps regarding their impact and measurements, especially in agriculture.

‘‘Limited knowledge exists on the potential risks these MNPs [micro nano plastics] may pose to global food safety and food security,’’ the paper said.

‘‘MNPs may cause changes to agricultural systems such as affecting soil properties, changing microbiomes and plant growth.’’

The study analysed academic literature that found chicks exposed to MNPs exhibited delayed growth and reduced feed intake compared with control groups.

Other studies on microplastic exposure found there was no impact.

The researcher said there was no evidence showing human babies were at risk.