Microplastics in infant formula: Research finds feeding bottles rife with contamination

20 Oct 2020 --- Irish researchers have found millions of microplastics are releasing from infant-feeding bottles (IFBs) during formula preparation. Moreover, they note a strong relationship between heat and microplastic release, meaning warmer liquids (formula or water used to sterilize bottles) result in a far greater release of microplastics.

However, it still remains to be seen whether microplastics can negatively impact infant health. “Around the implications – the simple answer is – we just don’t know. This is a new and rapidly evolving area of research and the data on the potential impact on human health is not well developed,” Professor Liwen Xiao from Trinity College, tells NutritionInsight.

The study indicates the daily use of plastic products is a prevalent source of microplastic release, meaning that the routes of exposure are much closer to us than previously thought. “We need to urgently assess the potential risks of microplastics to human health.”

“We are calling on policymakers to reassess the current guidelines for formula preparation when using plastic infant feeding bottles. Crucially, we have found that it is possible to mitigate the risk of ingesting microplastics by changing practices around sterilization and formula preparation,” says professor John Boland from Trinity College’s School of Chemistry.

The study’s key findings
Polypropylene infant-feeding bottles (PP-IFBs) can release up to 16 million microplastics and trillions of smaller nanoplastics per liter, the researchers support.

Sterilization and exposure to high-temperature water significantly increase microplastic release from 0.6 million to 55 million particles per liter when temperature increases from 25 to 95 °C.

Other PP-ware products (kettles, lunchboxes) release similar levels of microplastics, the researchers add.

The study indicates that the daily use of plastic products is a major source of microplastic release.The team undertook a global survey and estimated the exposure of 12-month-old infants to microplastics in 48 regions. Following current guidelines for infant feeding bottle sterilization and feeding formula preparation, the average daily exposure level for infants is in excess of 1 million microplastics. 

Oceania, North America and Europe have the highest levels of potential exposure, at 2,100,000, 2,280,000, and 2,610,000 particles per day, respectively.

Reducing the release of microplastics
The level of microplastics released from PP-IFBs can be significantly reduced by following modified sterilization and formula preparation procedures, the researchers support.

The researchers – from AMBER, the SFI Research Centre for Advanced Materials and Bioengineering Research, TrinityHaus and the Schools of Engineering and Chemistry at Trinity College Dublin – developed a set of recommendations for infant formula preparation when using plastic IFBs that minimize microplastic release.

Led by Dr. Jing Jing Wang and Professors Boland and Xiao, the team analyzed the potential for microplastics release from PP-IFBs during formula preparation by following international guidelines.

These recommendations include: 

• Sterilizing the bottle following WHO recommended guidelines and allow it to cool.
• Preparing sterilized water by boiling in a non-plastic kettle.
• Rinsing the sterilized bottle using room temperature sterilized water at least three times.

When preparing infant formula, the team suggests: 

• Preparing hot water using a non-plastic kettle.
• Preparing infant formula in a non-plastic container using at least 70℃ water. Cool to room temperature and transfer prepared formula into a high-quality plastic infant feeding bottle.

“Understanding microplastics’ fate and transport through the body following ingestion is an important focus of future research. Determining the potential consequences of microplastics on our health is critical for the management of microplastic pollution,” Xiao explains.

Zooming in on microplastics
According to the team, there is growing evidence to suggest that micro and nanoplastics are released into our food and water sources through the chemical and physical degradation of larger plastic items. 

Studies have demonstrated the potential transfer of micro and nanoplastics from oceans to humans via the food chain, but little is known about the direct release of microplastics from plastic products through everyday use.Polypropylene infant-feeding bottles can release up to 16 million microplastics per liter.

PP is one of the most commonly produced plastics for food preparation and storage globally. However, the capacity of PP to release microplastics was not appreciated until now, the researchers say.

They also note that given the prevalence of plastic products in daily food storage and food preparation and the fact that every PP product tested in the study released similar levels of microplastics, there is an urgent need for technological solutions.

“We don’t yet know the risks to human health of these tiny plastic particles, but we can develop behavioral and technological solutions and strategies to mitigate against their exposure,” say lead authors, Dr. Dunzhu Li and Dr. Yunhong Shi, researchers at CRANN and Trinity’s School of Engineering. 

In this space, a study by the Australian Cooperative Research Centre for Contamination Assessment and Remediation of the Environment found that opening plastic packages can catapult up to 75,000 microplastics across 3 m. 

In August, the World Health Organization (WHO) indicated that microplastics’ impact on human health appears to be minimal at current levels. 

However,  WHO stressed it was working from “limited information” and there is a pressing need to establish more standardized methods for measuring microplastic particles in water; more studies on the sources and occurrence of microplastics in freshwater; and the efficacy of different treatment processes.

Meanwhile, the European Commission unveiled a €750 billion (US$887 billion) COVID-19 recovery plan to revitalize the EU economy, which supports the European Green Deal. The latter was recently reinforced with a new Circular Economy Action Plan considering mandatory plastic requirements for recycled content, waste reduction measures and actions to reduce microplastic contamintation in packaging.

By Kristiana Lalou