October 19, 2020

expert reaction to study looking at microplastics and infant feeding bottles

A study, published in Nature Food, looked at microplastics and infant feeding bottles.

Dr Fay Couceiro, Senior Research Fellow in Biogeochemistry, University of Portsmouth, said:

 “This article shows the urgency for studies on microplastic impacts on human health. This is a well-considered and robust study although the extrapolation of the data to annual microplastic consumption in different countries is based on limited data. The study’s use of MicroRaman, rather than the more commonly used Fourier transform infrared (FTIR) method, for detection and identification of microplastics is especially important in the context of human health as FTIR identification of particles is limited to 10+ µm and from this study, we see that all of the microplastics are below that size.

“Even if the numbers of annual microplastic consumption by infants are overestimated due to the limited data available, the numbers released by a single correctly prepared feed are alarming. I am particularly concerned to see an extremely high load of nanoparticles, which are known to be capable of crossing cell membranes and entering human tissue. It is these smaller sized microplastic particles that have the potential to be retained by the body while the larger particles have so far all been shown to be excreted after ingestion1. The toxicity of the smaller nanoplastics entering the body’s cells is still severely understudied but nanoplastics have been shown to enter human cells and preliminary data have shown negative impacts2,3.

“Despite these concerns, it is important not to become alarmist and formula feeding is a necessity for many parents who cannot breastfeed for a variety of reasons. The risks from not sterilising bottles or using hot water are well understood and very real, and these known risks of disease must outweigh that of microplastic production until their health risks are understood. Further studies looking at other methods of formula feeding, such as cold sterilisation techniques and usage of pre-prepared formulas, are needed before any chances in guidance can be made.

“The topic of microplastic impacts on human health is in it’s infancy, but as all these studies suggest, it is time that this area is properly researched and so that the risks can be understood and mitigated.”

1 Schwabl, P. et al. Detection of various microplastics in human stool: a prospective case series. Ann. Intern. Med. 171, 453–457 (2019). https://doi.org/10.7326/M19-0618

2 Gopinath, P.M. et al. Assessment on interactive prospectives of nanoplastics with plasma proteins and the toxicological impacts of virgin, coronated and environmentally released-nanoplastics. Sci Rep 9, 8860 (2019). https://doi.org/10.1038/s41598-019-45139-6

3 Prüst et al. The plastic brain: neurotoxicity of micro- and nanoplastics. Particle and Fibre Toxicology (2020) 17:24 https://doi.org/10.1186/s12989-020-00358-y

Prof Oliver Jones, Professor of Analytical Chemistry and Associate Dean of Biosciences and Food Technology, RMIT University In Melbourne Australia, said:

“The findings of this paper may sound quite scary, at first, but we should keep in mind the research only looks at potential microplastic exposure, it does not look at potential effects of such exposure. Indeed, we really know very little about the effects of microplastics to children – or adults for that matter. The particles in the study are listed as being around 1-3 micrometres in size (for comparison, a printed full stop in a newspaper is ~300 μm across); it is quite possible they just pass out of the body very quickly.

“We also need to keep in mind that the final numbers in this paper are not measurements but estimates from a model – and any mathematical model is only as good as the data you put into it.  In this case there is a fair degree of uncertainty since the authors estimate how many bottles were in use in different countries by scraping sales data from the internet – mostly Amazon. They also assume each bottle shed microparticles the same way as in the lab tests, which they may not. This means the numbers listed in the paper should be treated as indications, not absolutes.  We certainly should not be making parents feel bad for using plastic bottles”.

“The above non-withstanding, this study is another piece of the puzzle that illustrates that microplastics problem is likely much bigger than we think. This issue is something we need to start really getting to grips with sooner rather than later.”

‘Microplastic release from the degradation of polypropylene feeding bottles during infant formula preparation’ by Li et al. was published in Nature Food at 16:00 UK time on Monday 19^th October 2020.

DOI: 10.1038/s43016-020-00171-y

Declared interests

Dr Fay Couceiro: I have no conflicting interests in this area.

Prof Oliver Jones: I have no conflicts of interest to declare though I have published research in the area of microplastic analysis (e.g. https://journals.sagepub.com/doi/full/10.1177/0003702820930292).