Ria Devereux
Previous studies have shown that micro and nano plastics are present in the human body including blood samples. This study expands on existing studies by looking at coronary blood and looking at these samples and chronic coronary disease and acute myocardial infarction.
The study does not show that micro and nanoplastics cause heart attacks. Instead, this study strengthens the theory or hypothesis that micro and nanoplastics may be harmful to our health but it does not change our current understanding or provide definitive causality.
There are multiple limitations within this study, including a small sample size (61 people), observational cross-sectional design, excluding a lot of potential micro and nanoplastics routes i.e diet, occupational exposure to name a few. Due to the studies design being cross sectional, it looks at exposure and disease at the same time and as a result it cannot say whether micro and nanoplastics caused the disease, increased due to the disease or are just in the blood due to environmental exposure. Another issue is that samples were taken during or after an event so it’s not clear if the presence of microplastic was high before the event.
The high percentage of smokers within the STEMI and CCS both over 70% also raises questions especially as the packs per year is higher in the STEMI group. This confirms what we already know about heart attacks being linked to smoking, but it makes it harder to work out if there is a link between microplastics and heart attacks, microplastics and smoking or if microplastic exposure is from something else.
The study is interesting and whilst it does not prove that micro-nano plastics cause heart attacks it does show the difficulties of moving microplastic studies that investigate impact on the human body from an extremely highly controlled laboratory study to real world human populations where studies become complicated by multiple factors like genetics, lifestyle, exposure and other factors influence disease risk.