Study Importance: Please rate the importance (0 = should be ignored/fatal flaw; 5=highest importance) of this study to the current understanding in the field. Please explain your rating

Answer Explanations

• 3

  Expert 5
  1. Scientific Importance: The study significantly contributes to the current understanding in the field, addresses a timely and relevant research problem. However, this study would be useful in providing a baseline as well as opening up new avenues for future research and suggests important questions for further investigation; unfortunately the issues with analytical methods, and the lack of using latest methodologies, techniques, and trends in microscopy, micro-spectroscopy (micro-FTIR, micro-Raman, SEM-EDS) coupling with the advanced and latest technique such as pyro-GC/MS which indicates a significant limitation. Also, the pyro-GC/MS could measure the concentration but not the shape and size; it’s a destructive method; and flawed with matrix effect for PVC and PET particularly (section 1.1). Therefore, coupling with micro-Raman and/or micro-FTIR techniques could confirm the single particle-based analysis as well as particles size and shape identification; which is this is lacking. 
   

  2. Interdisciplinary Impact: The study could discuss its potential impact on related fields or its interdisciplinary implications, highlighting how the findings might inform or influence other areas of research. 
• 2

  Expert 4
  Human exposure to MNPs is a topic of current scientific interest.  From that perspective, the study is important.  The authors have been able to secure some 'rare' specimens for research.  Apart from that the study lacks rigor in several critical elements to support their data and findings.  The quality/integrity of such specimens for intended purpose and the analytical method to measure target chemicals are poorly developed and executed.
   
• 5

  Expert 1
  The current study marks a substantial advancement over previous research, offering potentially valuable insights into the relationship between environmental exposure to microplastics and reproductive health.
• 3

  Expert 2
  I find it difficult to rate the study importance. When considering the study design and methods used as well as the presentation and interpretation of the results, then the study importance is to be ranked as being very low (1). However, on the other hand the topic of microplastics in especially human tissues is of great regulatory and scientific interest and study results like in this case, although being immature and flawed in my opinion, are often taken for granted, quoted a lot, and they are actually used for building cases for regulatory actions and identification of further research. This has the potential of taking the wrong actions and focussing on less-relevant research needs.
  The study in my opinion does not advance the state of the science and my overall evaluation is that far more background research is needed before the study results can be reliably interpreted and used for policy making or any other regulatory action.
• 5

  Expert 3
  Pros
  -  Human and animal health consequences from microplastics are very important to study. 
  -  There have been only a few studies on human health outcomes of microplastics and we need a lot more research in this area to fully understand the consequences of these materials that we are exposed to at relatively high doses. 
  - Although I am very critical of the specific findings and methods conducted, I feel that this work was deserving of publication. Early studies like this will often have methodological challenges that are figured out as the field matures. 
  
  Cons  
  - None